Wednesday night (1/6), I decided to work on improving my 220 MHz mobile "station". Up until now, I've been using a Comet tri-band whip with a 5W TYT F9 HT, and that's worked okay. But I've had a 5/8-wave mobile antenna sitting around for about a week now, waiting to be tuned.
The Opek VH-1216 is a monoband whip with a matching network at the base. It's pretty simple; no phasing coils or loading coils. Unfortunately, it doesn't ship tuned to the amateur FM portion of the band. I really don't have the tools to nibble away at a stainless rod, but I have a brother in St. Louis Park that does. He has an angle grinder that slices through the rod easily, and a wire wheel to take off the burr. It took me longer to explain the process to him than it did to make the first cut and test it with an SWR metre. In total, I'd guess that two inches at least had to be trimmed off, but the match was nearly perfect on FM simplex frequencies and pretty darn good at repeater input frequencies.
My expectation was for a bit of improvement over the Anli DC-124H tri-band whip and the Comet SSB224 tri-band whip that I'd been using before. Multi-band antennae are always a compromise, and are intermod magnets because they are open to a much larger range of frequencies than a monoband. Mostly, though, I just expected a better match by using the monoband.
I was using my Kenwood TH-F6A HT for a mobile rig. Normally, this isn't a great choice because the F6A is a wide-band receiver that works from HF to 1.2 GHz, and it has a front end that will let virtually anything through for that reason. I did this because I wanted to see if a monoband antenna would reduce the intermod issues.
To test the antenna, I chose a long-shot repeater that I had trouble reaching from home: the 223.900- (100.0 PL) Aggrandizer. Being in one of the lowest spots in St. Louis Park, and running only five watts, I fully expected a failure to even "ker-chunk" the .900 machine. To my immense surprise, the signal came back at S9! Still, there was no way that I could reach the 224.94- repeater in New Brighton...was there? Yeah. I got an S6 from it.
This was starting to get exciting! As I got on the I-394 frontage road, the 224.94 was now about S8, and I even got an intermittent S3 from the .880 in Maplewood. Even better, I heard no intermod at all. Satisfied that I was actually getting out, I threw out my sign on the 223.940 HandiHam repeater in hopes of getting a signal check. Just because you can "ker-chunk" repeaters, that doesn't mean that you're readable.
And so I got another surprise. WA0RA (Ron) came back to my sign, and he was on the 220 side. The 223.940- is cross-band linked to the two-metre 145.450 and a few UHF repeaters, and I expected to get someone on one of the other bands. Instead, I got a great test of my reach in to the repeater in Arden Hills. The 223.940 was S9, of course, and Ron said that I was full-quieting into it. It was "only" 12 miles away, but it would be a stretch to call my rig "modest", too.
I stuck with Ron on the 223.94, half-believing that I'd drop out as I worked my way through the hills and valleys of New Hope. As it turned out, Ron had just got a 25W Alinco monoband mobile and had an exterior J-pole set up. As he was in Blaine, he was blasting into the Arden Hills repeater at full power, but he soon dropped down to 10W. We have a new operator on the local 1.25M band, and that's good news. I'll have to try some FM simplex with him when I run into him on the local repeaters.
Overall, my new antenna has worked really well. Driving around Plymouth, I'm getting great signals from the local 1.25M repeaters. My goal is to use my TYT HT as a 1.25M mobile to access the HandiHam network when I switch to a full-powered UHF monoband rig soon. It sure looks as if I'll be able to reach the 1.25M HandiHam repeater easily from this side of town. If you've got an HT for the 1.25M band, you might be surprised what you can do with a home-made 1/4-wave ground-plane or a J-pole.
Showing posts with label antennae. Show all posts
Showing posts with label antennae. Show all posts
Saturday, 9 January 2016
Saturday, 9 May 2015
UHF vertical dipole
I saw this UHF dipole on AliExpress for only $5 (with free shipping) and it made me want to point it out as another inexpensive option for indoor HT use. It has an adhesive surface so that it can be stuck to a window and used as a vertical dipole. Vertical dipoles have decent gain and low SWR, as long as the feed-line is kept perpendicular to the antenna for a distance.
Obviously, the cable is the thin, lossy type that's entirely inappropriate for UHF frequencies. Some simple modification can fix that easily, though. Just cut the cable about 15 inches (not critical) from the antenna feed-point and crimp on a new connector (e.g. SO-239 or PL-259). Then you can use RG-8X to connect between your radio and the short piece of lousy cable. Remember, you can't let the short piece of lousy cable hang down. It has to be held at a right angle, so you can tape it to the wall (or use some other clever solution).
This is another very unobtrusive means of getting on UHF for those that live in apartments, or even those that would like a second radio in another room (e.g. the kitchen) without running another feed-line to their "good" antenna. You'll find that a vertical dipole has better gain than a mag-mounted 1/4-wave whip.
Of course, you could also simply make a vertical dipole by cutting the connector off a piece of RG-8X, soldering a piece of wire to the centre conductor and another to the ground braid, and taping the wires to your window. You'll need a dual-band SWR meter, but you should probably have one of those if you intend to experiment with antennae anyway. If nothing else, borrow one from a local ham. Just trim the wires with tiny cuts until the SWR is best -- probably between six and seven inches.
Obviously, the cable is the thin, lossy type that's entirely inappropriate for UHF frequencies. Some simple modification can fix that easily, though. Just cut the cable about 15 inches (not critical) from the antenna feed-point and crimp on a new connector (e.g. SO-239 or PL-259). Then you can use RG-8X to connect between your radio and the short piece of lousy cable. Remember, you can't let the short piece of lousy cable hang down. It has to be held at a right angle, so you can tape it to the wall (or use some other clever solution).
This is another very unobtrusive means of getting on UHF for those that live in apartments, or even those that would like a second radio in another room (e.g. the kitchen) without running another feed-line to their "good" antenna. You'll find that a vertical dipole has better gain than a mag-mounted 1/4-wave whip.
Of course, you could also simply make a vertical dipole by cutting the connector off a piece of RG-8X, soldering a piece of wire to the centre conductor and another to the ground braid, and taping the wires to your window. You'll need a dual-band SWR meter, but you should probably have one of those if you intend to experiment with antennae anyway. If nothing else, borrow one from a local ham. Just trim the wires with tiny cuts until the SWR is best -- probably between six and seven inches.
New 2M Yagi is exciting
The 2M Yagi that I ordered off of EBay arrived, and it works great! Simplicity itself, it's made out of PVC pipe and tape measures. The boom is sectional, and the elements fold in for relatively compact storage and carrying. At a price of $35, the seller is definitely making a profit, but the design is a sound one. The only thing that I'd even begin to take issue with is the choice of a BNC connector on the coaxial cable pigtail. The seller should at least offer SMA or PL-259 as an option, especially since the three-foot pigtail will probably need to be extended.
I improvised a mount on my tripod by putting a wooden dowel in the horizontal mount hole and using hose clamps to attach the "handle" of the Yagi to the dowel. I'm working on a more robust mounting scheme, as well as an adapter that would allow this antenna to be mounted on any common photographic tripod. Still, just to test it out, this hokey arrangement worked well enough.
Setting my FT-897D on the lowest VHF output available (5W), I adjusted the mast of the tripod to be about shoulder height. This would allow the antenna to be used on my balcony without being seen from the ground and attracting the attention of my neighbours. Pointing it roughly east, I tried a relatively easy repeater first to test the SWR -- the 145.290- in New Brighton. The SWR was virtually flat, and the repeater came back with a full-scale signal (as it usually does, even with a 1/4-wave whip). Next, I tried K0LAV's (Paul) new 147.390+ repeater with identical results.
Moving on to bigger challenges, I tried the St. Paul 145.310+ and 145.170- repeaters. These usually both require at least 10W to "ker-chunk", and 15W to work readably, with my whip from here on the other side of town. With the new Yagi (mounted fairly low, remember), they both opened up with only 5W and came back with full-scale (S++) signals instead of their usual S9. Likewise with the 146.985- in Inver Grove Heights. Now we were getting somewhere!
Pointing the beam north, while still keeping it low, the Isanti 145.210- responded with 5W and an S9 signal -- and this was with the signal going through the wall on the balcony. That was promising. Swinging the beam to the south-west brought in the Faribault 146.790- machine with an S4 signal, though I couldn't "ker-chunk" it with such low power.
So I raised the mast to roof-top height, as it was already getting dark anyway. Free of obstructions, 5W now opened up the Faribault repeater and gave S8 on the return. The Baldwin 145.250- also came in clearly. The Balsam Lake 147.195+ repeater took 10W to "ker-chunk" it, and only came back S4 or so, but that's a decent haul for such a compromise arrangement without superior propagation conditions.
I was pretty pleased with the performance and the options this new antenna would offer me, even keeping it low. Even better was that I now finally had a horizontal 2M antenna for weak-signal work. I turned it to mount horizontally and kept it a roof-top level, trying some two-metre CW. I was very surprised to find that horizontal polarisation eliminated virtually all of the interference with my TV and stereo -- and the potential for annoying my neighbours. Unsurprisingly, I found no one coming back to me on CW. Likewise with two-metre SSB on 144.200, but that mode of operation is now open to me.
Lowering the antenna, I was just about to call it a night when I got the crazy idea to try the new Yagi on UHF. I set the output to the lowest level (2W) to avoid damaging the radio, and uttered the words "KD0TLS test" on the MARA 444.800+ repeater. The SWR was higher, but still within acceptable range (about 1.6:1). That was pretty amazing in itself, but it was even more amazing to hear K0LAV and KE0ALI (Josh) come back to my sign with a report that I was full-quieting into the machine. With just two watts and the mast un-raised!
With it's light weight (virtually nothing), it's dual-band capability, and its ability to break down and fold up, this could be an inexpensive option to play with FM satellites, take camping, or take down to the park for a little portable operation on a sunny day. It also allows you to greatly improve your signal operating indoors with an HT. I was able to attach it to a floor mic stand (like musicians use to mic their amps), and get acceptable performance indoors -- though it works much better outdoors on VHF.
What it's not good for is mounting on your roof, since the tape measure elements aren't rigid at all. For portable use in windy conditions, you could tape thin wooden dowels to the elements, I suppose.
I picked up a length of PVC pipe, and I'll be working on an improved mounting solution. I expect that this new antenna will be used quite often in my rotation at my restrictive condo location.
I improvised a mount on my tripod by putting a wooden dowel in the horizontal mount hole and using hose clamps to attach the "handle" of the Yagi to the dowel. I'm working on a more robust mounting scheme, as well as an adapter that would allow this antenna to be mounted on any common photographic tripod. Still, just to test it out, this hokey arrangement worked well enough.
Setting my FT-897D on the lowest VHF output available (5W), I adjusted the mast of the tripod to be about shoulder height. This would allow the antenna to be used on my balcony without being seen from the ground and attracting the attention of my neighbours. Pointing it roughly east, I tried a relatively easy repeater first to test the SWR -- the 145.290- in New Brighton. The SWR was virtually flat, and the repeater came back with a full-scale signal (as it usually does, even with a 1/4-wave whip). Next, I tried K0LAV's (Paul) new 147.390+ repeater with identical results.
Moving on to bigger challenges, I tried the St. Paul 145.310+ and 145.170- repeaters. These usually both require at least 10W to "ker-chunk", and 15W to work readably, with my whip from here on the other side of town. With the new Yagi (mounted fairly low, remember), they both opened up with only 5W and came back with full-scale (S++) signals instead of their usual S9. Likewise with the 146.985- in Inver Grove Heights. Now we were getting somewhere!
Pointing the beam north, while still keeping it low, the Isanti 145.210- responded with 5W and an S9 signal -- and this was with the signal going through the wall on the balcony. That was promising. Swinging the beam to the south-west brought in the Faribault 146.790- machine with an S4 signal, though I couldn't "ker-chunk" it with such low power.
So I raised the mast to roof-top height, as it was already getting dark anyway. Free of obstructions, 5W now opened up the Faribault repeater and gave S8 on the return. The Baldwin 145.250- also came in clearly. The Balsam Lake 147.195+ repeater took 10W to "ker-chunk" it, and only came back S4 or so, but that's a decent haul for such a compromise arrangement without superior propagation conditions.
I was pretty pleased with the performance and the options this new antenna would offer me, even keeping it low. Even better was that I now finally had a horizontal 2M antenna for weak-signal work. I turned it to mount horizontally and kept it a roof-top level, trying some two-metre CW. I was very surprised to find that horizontal polarisation eliminated virtually all of the interference with my TV and stereo -- and the potential for annoying my neighbours. Unsurprisingly, I found no one coming back to me on CW. Likewise with two-metre SSB on 144.200, but that mode of operation is now open to me.
Lowering the antenna, I was just about to call it a night when I got the crazy idea to try the new Yagi on UHF. I set the output to the lowest level (2W) to avoid damaging the radio, and uttered the words "KD0TLS test" on the MARA 444.800+ repeater. The SWR was higher, but still within acceptable range (about 1.6:1). That was pretty amazing in itself, but it was even more amazing to hear K0LAV and KE0ALI (Josh) come back to my sign with a report that I was full-quieting into the machine. With just two watts and the mast un-raised!
With it's light weight (virtually nothing), it's dual-band capability, and its ability to break down and fold up, this could be an inexpensive option to play with FM satellites, take camping, or take down to the park for a little portable operation on a sunny day. It also allows you to greatly improve your signal operating indoors with an HT. I was able to attach it to a floor mic stand (like musicians use to mic their amps), and get acceptable performance indoors -- though it works much better outdoors on VHF.
What it's not good for is mounting on your roof, since the tape measure elements aren't rigid at all. For portable use in windy conditions, you could tape thin wooden dowels to the elements, I suppose.
I picked up a length of PVC pipe, and I'll be working on an improved mounting solution. I expect that this new antenna will be used quite often in my rotation at my restrictive condo location.
Sunday, 19 October 2014
My new UHF / GMRS antenna
I got a new antenna, and it's "different". No, it's not some cheap Chinese antenna that's deceptively marketed and doesn't work. It's the Italian-made Sirio GP 430 UHF antenna that I bought from DNJ Radio. It's a lot like a beer can with three radials sticking out of the bottom, and an SO-239 on the bottom. A tube is supposed to go in the bottom and allow you to mount it to a mast, but that mount is out-of-stock at the moment. So I set it up on a table on my balcony and tried it out like you see below.
I got this antenna because I was tired of switching between my UHF (440 MHz) ham antenna and my GMRS antenna while using my UHF TYT TH-9000. As you can see from the label, this antenna covers both.
Okay, if you can't read it, it says 380 - 480 MHz. That's pretty wide-band, and it's possible because of the large OD of the radiating element. It's a 1/4-wave folded dipole, which means "unity gain". But the idea of "gain" from vertical antennae is sort of deceptive to begin with. The angled radials help to keep the angle of radiation lower than what I get from my 1/4-wave whip mag-mounted on the balcony's steel cap.
I didn't get it for "gain", anyway. Aside from allowing 440 and GMRS operation with the same antenna, I was looking for a ground-plane antenna. My other gambles on UHF ground-planes have been disappointing, and the balcony's steel cap is not an ideal ground for a mag-mounted whip. I'd expect "gain" over my dual-band mobile whips just by virtue of having the ground radials. And it looks as if that steel cap will be gone next year when they renovate the balconies, so I need a real ground solution.
The other reason that I got this antenna was for stealth. I live in a condo, and antennae aren't really allowed. Much of what comprises the concept of stealth is merely placing antennae in plain sight, while making them appear (to a non-ham) as something other than an antenna. For example, a length of PVC pipe conceals a roll-up J-pole. Most hams would immediately recognise this as an antenna if it were mounted on a condo balcony. Non-hams just see a piece of PVC pipe, which isn't against the HOA regulations. Horizontally-strung wires, with the tell-tale centre conductor and coax running out, are a dead give-away, on the other hand. You could put an upside-down flower pot over a mag-mounted 1/4-wave UHF whip on your steel patio table. Nobody would think twice about it, except perhaps to think that you're slightly untidy. With this UHF antenna, all that I need to do is conceal the radials -- perhaps with cloth or nylon to make it look like an umbrella. Sure, it would look a bit stupid...but it wouldn't look like an antenna to a non-ham. That stupid-looking umbrella-thing opens up all of the 440 MHz repeaters to me, plus GMRS, and nobody's going to know but me.
The SWR was virtually flat on both UHF and GMRS just setting it on the balcony table. Setting it on the floor inside, or on top of a metal rack outside, produced higher mismatches but not high enough to warrant concern. Once it's mounted on a piece of PVC or wooden dowel, I expect that SWR won't be an issue.
Just because it tunes up, that doesn't means that it performs well, though. I set it near the window in my home office, and the received signals from repeaters were generally lower using the GP 430 than using a Browning BR-180 dual-band mag-mounted on top of an old stereo receiver. But I don't plan on using it indoors.
Sirio makes another UHF / GMRS antenna that has more gain, is cheaper, but is not quite as stealthy.
I got this antenna because I was tired of switching between my UHF (440 MHz) ham antenna and my GMRS antenna while using my UHF TYT TH-9000. As you can see from the label, this antenna covers both.
Okay, if you can't read it, it says 380 - 480 MHz. That's pretty wide-band, and it's possible because of the large OD of the radiating element. It's a 1/4-wave folded dipole, which means "unity gain". But the idea of "gain" from vertical antennae is sort of deceptive to begin with. The angled radials help to keep the angle of radiation lower than what I get from my 1/4-wave whip mag-mounted on the balcony's steel cap.
I didn't get it for "gain", anyway. Aside from allowing 440 and GMRS operation with the same antenna, I was looking for a ground-plane antenna. My other gambles on UHF ground-planes have been disappointing, and the balcony's steel cap is not an ideal ground for a mag-mounted whip. I'd expect "gain" over my dual-band mobile whips just by virtue of having the ground radials. And it looks as if that steel cap will be gone next year when they renovate the balconies, so I need a real ground solution.
The other reason that I got this antenna was for stealth. I live in a condo, and antennae aren't really allowed. Much of what comprises the concept of stealth is merely placing antennae in plain sight, while making them appear (to a non-ham) as something other than an antenna. For example, a length of PVC pipe conceals a roll-up J-pole. Most hams would immediately recognise this as an antenna if it were mounted on a condo balcony. Non-hams just see a piece of PVC pipe, which isn't against the HOA regulations. Horizontally-strung wires, with the tell-tale centre conductor and coax running out, are a dead give-away, on the other hand. You could put an upside-down flower pot over a mag-mounted 1/4-wave UHF whip on your steel patio table. Nobody would think twice about it, except perhaps to think that you're slightly untidy. With this UHF antenna, all that I need to do is conceal the radials -- perhaps with cloth or nylon to make it look like an umbrella. Sure, it would look a bit stupid...but it wouldn't look like an antenna to a non-ham. That stupid-looking umbrella-thing opens up all of the 440 MHz repeaters to me, plus GMRS, and nobody's going to know but me.
 |
| View from the bottom |
Just because it tunes up, that doesn't means that it performs well, though. I set it near the window in my home office, and the received signals from repeaters were generally lower using the GP 430 than using a Browning BR-180 dual-band mag-mounted on top of an old stereo receiver. But I don't plan on using it indoors.
Sirio makes another UHF / GMRS antenna that has more gain, is cheaper, but is not quite as stealthy.
Friday, 10 October 2014
The Hype of Vertical Antenna "Gain"
One of the things that makes me roll my eyes in on-the-air discussions is the subject of the "gain" of vertical antennae. The conventional wisdom is that you want the highest gain possible, but this is a fallacy.
Vertical antennae are omnidirectional. It's not like a vertical Yagi or log periodic that concentrates your signal in a particular direction. Whatever "gain" you get from a vertical antennae comes from the angle of radiation (often called "tilt" or "take off angle"). The angle of radiation also changes with the height the antenna is mounted, and the quality of the ground plane. A lower or higher angle of radiation can be good or bad, depending on your situation.
A 1/4-wave whip on your car is going to have a higher angle of radiation -- about 45 degrees. But the 1/4-wave "unity gain" (insert scoff here) also has the widest lobes. This means that the difference between the "gain" at 45 degrees "tilt" and the gain at 15 degrees "tilt" isn't nearly as pronounced as what you would find at those same angles with a 5/8-wave whip -- all other factors being equal.
The 5/8-wave whip gives you a lower angle of radiation -- about 15 degrees, if you have a ground-plane. You can get that angle lower if you want to drive around with an 5/8-wave antenna mounted 70 feet or so above your car. But that "gain" is concentrated in a much narrower angular range. Generally speaking, the higher that any antenna is mounted, the lower the angle of radiation.
A lower angle of radiation is not always better, though. If you're in a valley and the repeater is high up on a hill, the 1/4-wave is the better choice. On flat terrain, the 5/8-wave is superior -- again, all other factors being equal.
The quality of the ground-plane is an additional factor. In a mobile situation, your car's body is the ground-plane, and it creates (or tries to create) an identical antenna of the same wavelength, only beneath the "real" antenna. The reason that you see 1/4-wave ground-plane antennae with the radials sloping downward at a 45-degree angle is that this tends to lower the angle of radiation. If you try to pull this trick off with a 5/8-wave antenna, you should use sloping 5/8 radials. In a mobile situation, you aren't using radials at all, though. If your antenna isn't mounted on the roof, there might not even be 5/8-wavelength between the feed-point and ground to construct an electrically and magnetically sound imaginary lower portion.
On UHF mobile applications especially, much of the perceived "gain" of a 5/8 whip comes by virtue of the fact that the antenna is simply higher than a 1/4-wave whip. Altitude is the trump card on UHF, as the band is much more line-of-sight. But a 1/4-wave, with it's wider lobes, can offer more potential to bounce off electrically-reflective tall buildings and such at UHF frequencies, and thus extend your range in ways that a 5/8-wave can't.
It's complicated subject, but this idea that a 5/8-wave whip has more "gain" and makes your signal stronger in every case is hype. This also neglects the idea of the use of a phasing coil to create "1/4-wave over 1/4-wave" or "5/8-over 5/8" whips. For example, the Browning BR-180 is a 5/8-over 5/8 UHF mobile whip. An arrangement like this generally lowers the angle of radiation significantly more than a straight whip, but the lobes are even narrower. As your "gain" is now compressed into a tight band, any movement of the antenna creates stronger "flutter" than you would see in a standard whip. The 1/4-wave also has much less "flutter", because of its wider lobes. It also is shorter, and thus generally more rigid.
More "gain" can easily make your radio more susceptible to "intermod", too. Even though the 'experts' - who merely parrot "conventional wisdom" - have been told by their Wise Elders that a 5/8-wave is the hands-down superior antenna (more GAIN!), it's more complicated than that. If you are out in the suburban or exurban reaches trying to get into a repeater in town, a 5/8-wave would probably be your best choice. If you are driving around inside Minneapolis proper and talking on the .850, though, a 1/4-wave whip would be the superior antenna.
Repeaters often use stacked verticals to get a negative angle of radiation (i.e. point the signal back at the ground). A 5/8-wave antenna on a tall building is a disaster, because the signal will still be pointing up into the sky.
Again, vertical antennae don't concentrate your transmitted signal in any particular horizontal direction, unless you have multiple antennae in a collinear arrangement on your vehicle or something like a vertical multi-element Yagi at home. Whatever 'gain' you get from a simple whip is concentrated at an angle into the sky.
Vertical antennae are omnidirectional. It's not like a vertical Yagi or log periodic that concentrates your signal in a particular direction. Whatever "gain" you get from a vertical antennae comes from the angle of radiation (often called "tilt" or "take off angle"). The angle of radiation also changes with the height the antenna is mounted, and the quality of the ground plane. A lower or higher angle of radiation can be good or bad, depending on your situation.
A 1/4-wave whip on your car is going to have a higher angle of radiation -- about 45 degrees. But the 1/4-wave "unity gain" (insert scoff here) also has the widest lobes. This means that the difference between the "gain" at 45 degrees "tilt" and the gain at 15 degrees "tilt" isn't nearly as pronounced as what you would find at those same angles with a 5/8-wave whip -- all other factors being equal.
The 5/8-wave whip gives you a lower angle of radiation -- about 15 degrees, if you have a ground-plane. You can get that angle lower if you want to drive around with an 5/8-wave antenna mounted 70 feet or so above your car. But that "gain" is concentrated in a much narrower angular range. Generally speaking, the higher that any antenna is mounted, the lower the angle of radiation.
A lower angle of radiation is not always better, though. If you're in a valley and the repeater is high up on a hill, the 1/4-wave is the better choice. On flat terrain, the 5/8-wave is superior -- again, all other factors being equal.
The quality of the ground-plane is an additional factor. In a mobile situation, your car's body is the ground-plane, and it creates (or tries to create) an identical antenna of the same wavelength, only beneath the "real" antenna. The reason that you see 1/4-wave ground-plane antennae with the radials sloping downward at a 45-degree angle is that this tends to lower the angle of radiation. If you try to pull this trick off with a 5/8-wave antenna, you should use sloping 5/8 radials. In a mobile situation, you aren't using radials at all, though. If your antenna isn't mounted on the roof, there might not even be 5/8-wavelength between the feed-point and ground to construct an electrically and magnetically sound imaginary lower portion.
On UHF mobile applications especially, much of the perceived "gain" of a 5/8 whip comes by virtue of the fact that the antenna is simply higher than a 1/4-wave whip. Altitude is the trump card on UHF, as the band is much more line-of-sight. But a 1/4-wave, with it's wider lobes, can offer more potential to bounce off electrically-reflective tall buildings and such at UHF frequencies, and thus extend your range in ways that a 5/8-wave can't.
It's complicated subject, but this idea that a 5/8-wave whip has more "gain" and makes your signal stronger in every case is hype. This also neglects the idea of the use of a phasing coil to create "1/4-wave over 1/4-wave" or "5/8-over 5/8" whips. For example, the Browning BR-180 is a 5/8-over 5/8 UHF mobile whip. An arrangement like this generally lowers the angle of radiation significantly more than a straight whip, but the lobes are even narrower. As your "gain" is now compressed into a tight band, any movement of the antenna creates stronger "flutter" than you would see in a standard whip. The 1/4-wave also has much less "flutter", because of its wider lobes. It also is shorter, and thus generally more rigid.
More "gain" can easily make your radio more susceptible to "intermod", too. Even though the 'experts' - who merely parrot "conventional wisdom" - have been told by their Wise Elders that a 5/8-wave is the hands-down superior antenna (more GAIN!), it's more complicated than that. If you are out in the suburban or exurban reaches trying to get into a repeater in town, a 5/8-wave would probably be your best choice. If you are driving around inside Minneapolis proper and talking on the .850, though, a 1/4-wave whip would be the superior antenna.
Repeaters often use stacked verticals to get a negative angle of radiation (i.e. point the signal back at the ground). A 5/8-wave antenna on a tall building is a disaster, because the signal will still be pointing up into the sky.
Again, vertical antennae don't concentrate your transmitted signal in any particular horizontal direction, unless you have multiple antennae in a collinear arrangement on your vehicle or something like a vertical multi-element Yagi at home. Whatever 'gain' you get from a simple whip is concentrated at an angle into the sky.
Thursday, 22 May 2014
My new stuff, plus various tidbits
I've had a bit of good luck this week with my antenna situation. For those of you that haven't seen my tripod-mounted antenna at Aerials In The Park (AITP) - which is most hams in the metro - I have a thirteen-foot aluminum tripod (fully extended) with a radial NMO mount that allows me to use mobile whips as ground-plane antennae. I had problems with this arrangement at AITP due to high SWR. I've now discovered that one of the right-angle adapters for the coaxial cable was defective and affecting the SWR, with the effect being most pronounced on UHF. Because the LMR 400 cable is so stiff, I need a right-angle adapter to avoid keeping my FT-897 eight inches from the wall when it sits on my desk. I was really happy to find that I could reach the MAGIC 444.050+ UHF machine run by N0GOI (Terry) with only ten watts last night using this new arrangement. Before, I struggled to get into his repeater with fifteen watts from here in Plymouth. The radials make a lot of difference over the mag-mount that I usually use, as the steel cap of the balcony only extends in two directions. The mag-mount antenna is fine for the majority of local repeaters, and has excellent SWR, but the new radial arrangement allows me to reach more challenging repeaters.
Next on the list is getting the VHF/UHF Yagi tuned up that the guys at AITP helped me re-assemble. While it doesn't mount horizontally for weak-signal modes, I'm still looking forward to a dramatic improvement in my two-metre FM performance -- especially simplex. While I have to keep it low enough that it can't be seen from the ground during daylight hours, I still expect big things.
In a few weeks, I expect the arrival of my UHF TYT TH-9000 from China. I'm thinking about putting it in my home office and using it for 70 cm and GMRS with an indoor antenna, but I'm realistic enough to settle for setting it next to my 1.25M TH-9000 and using an exterior antenna. I've also got a new power supply that has enough juice to let me run either the UHF or 1.25M rig at full power. My successes with 1.25M FM simplex make me think that UHF FM simplex might be practical. As always, I'll be looking for people willing to experiment with this, as well as GMRS.
Next week, I should be getting the VHF version of the tiny UHF mobile antenna that I wrote about previously. The UHF model worked surprisingly well, and I expect that this new antenna will let me hit the major local two-metre machines with a readable signal from my car. I'll write up a report on its performance, and hopefully I can get some signal reports from some of you out there to help with that. I really don't understand how these "phantom elite" antennae work, and if they were cheaper I'd cut one open to satisfy my curiosity. Wouldn't it be interesting to be able to drive around town with a 5W HT and a 3" antenna, while working two-metre repeaters? It's not for everybody, of course.
What else?
Amazon still has the TYT TH-9000 1.25M models available, as does 446shop. These won't be around very long, though. Somebody buy two and set up a makeshift repeater until we get the others back into shape.
N0YNT (Matt) is mulling over setting up some kind 1.25M repeater at the U of M, though it sounds more like a translator than a true repeater. As I understand it, it would re-transmit the signals on the 147.150 and 444.425 machines on 222 MHz, but would not allow two-way communications on the band. N0DSH (Frank) is generously donating a four-element Yagi to the cause, so this could actually get off the ground and get some activity on the 222 MHz band. Matt also bought several two-metre repeaters at Dayton to add to his hoard, so who knows what new machines might be appearing on VHF in the future?
N0GOI (Terry) is picking up two VHF repeaters from the South-west to go in to Mille Lacs County for SkyWarn. At some point, they may be linked to the metro. Also at some point, Terry's 444.050+ machine might be linked to the HandiHam network, adding St. Paul to the UHF side of the cross-band scheme.
N0XOC has a tumblr blog up focused on HF with some interest in NVIS antennae. Let's hope that he keeps it up, because he's doing some interesting experimentation.
KD0UDM (Neal) has an experimental, low-power 1.25M repeater set up at 224.240 MHz. Can you "ker-chunk" it? Send him a signal report if you can.
Next on the list is getting the VHF/UHF Yagi tuned up that the guys at AITP helped me re-assemble. While it doesn't mount horizontally for weak-signal modes, I'm still looking forward to a dramatic improvement in my two-metre FM performance -- especially simplex. While I have to keep it low enough that it can't be seen from the ground during daylight hours, I still expect big things.
In a few weeks, I expect the arrival of my UHF TYT TH-9000 from China. I'm thinking about putting it in my home office and using it for 70 cm and GMRS with an indoor antenna, but I'm realistic enough to settle for setting it next to my 1.25M TH-9000 and using an exterior antenna. I've also got a new power supply that has enough juice to let me run either the UHF or 1.25M rig at full power. My successes with 1.25M FM simplex make me think that UHF FM simplex might be practical. As always, I'll be looking for people willing to experiment with this, as well as GMRS.
Next week, I should be getting the VHF version of the tiny UHF mobile antenna that I wrote about previously. The UHF model worked surprisingly well, and I expect that this new antenna will let me hit the major local two-metre machines with a readable signal from my car. I'll write up a report on its performance, and hopefully I can get some signal reports from some of you out there to help with that. I really don't understand how these "phantom elite" antennae work, and if they were cheaper I'd cut one open to satisfy my curiosity. Wouldn't it be interesting to be able to drive around town with a 5W HT and a 3" antenna, while working two-metre repeaters? It's not for everybody, of course.
What else?
Amazon still has the TYT TH-9000 1.25M models available, as does 446shop. These won't be around very long, though. Somebody buy two and set up a makeshift repeater until we get the others back into shape.
N0YNT (Matt) is mulling over setting up some kind 1.25M repeater at the U of M, though it sounds more like a translator than a true repeater. As I understand it, it would re-transmit the signals on the 147.150 and 444.425 machines on 222 MHz, but would not allow two-way communications on the band. N0DSH (Frank) is generously donating a four-element Yagi to the cause, so this could actually get off the ground and get some activity on the 222 MHz band. Matt also bought several two-metre repeaters at Dayton to add to his hoard, so who knows what new machines might be appearing on VHF in the future?
N0GOI (Terry) is picking up two VHF repeaters from the South-west to go in to Mille Lacs County for SkyWarn. At some point, they may be linked to the metro. Also at some point, Terry's 444.050+ machine might be linked to the HandiHam network, adding St. Paul to the UHF side of the cross-band scheme.
N0XOC has a tumblr blog up focused on HF with some interest in NVIS antennae. Let's hope that he keeps it up, because he's doing some interesting experimentation.
KD0UDM (Neal) has an experimental, low-power 1.25M repeater set up at 224.240 MHz. Can you "ker-chunk" it? Send him a signal report if you can.
Saturday, 17 May 2014
A Tale of Two Antennae Manufacturers
Prior to the last AITP (Aerials In The Park) event, I ordered two antennae: a Jetstream JTBM270 Yagi and a Centerfire UHF 1/4-wave ground-plane. At the first event, I found that the radials for my clever mount were more suited for VHF than UHF, so I figured out a way to easily swap antennae on the tripod by switching masts. So I had four antennae: the VHF radial-mount with a 5/8-wave mobile whip, the UHF 1/4-wave ground-plane, a 1.25M Centerfire Yagi, and the Jetstream VHF/UHF Yagi.
Of these, the Jetstream VHF/UHF Yagi was the most expensive and most frustrating. The assembly instructions were vague, the elements were colour-coded to confound colour-blind people like me, and it arrived with missing hardware. Not a single lock-washer was included, and a set screw was missing for the T-match. Within an hour of receiving it, I was on the phone with Jetstream in Ohio asking them to send the missing hardware. My call was handed to a guy that never gave his name, never apologised, and seemed highly confused. He obsessed over whether the antenna was VHF or UHF, as if that mattered with regard to lock-washers and set screws. I gave him the model number twice, and told him that it was a dual-band Yagi, which apparently is an unacceptable answer. He pointedly asked me to look at the package that the antenna came in and tell him if it said "UHF" or "VHF". He did this twice. I finally read the entire package to him verbatim, which he simply, flat-out, did not believe. Was I sure it was a Jetstream antenna? Yeah, I was. Finally, after much sighing, he took my address and said that he would send the missing hardware. It's been two weeks now, and it still isn't here. Instead, I went to the hardware store the day before AITP and got everything that I needed.
In total contrast, I had to contact Centerfire Antenna after AITP because I had lost one of the elements for my 1.25M Yagi at the event. A quick email to Ben there was immediately responded to on a Sunday, and he said that a replacement element would be sent the next day. He even followed up and notified me that it had been sent. And it actually arrived. No charge, no argument, no run-around. And the entire issue was entirely my fault.
So I'm back on 222 MHz again, after a couple of weeks. I've also ordered a new power supply so that I can use my 1.25M TH-9000 at full power, if need be. Today I'm going to work on the Jetstream Yagi and get it tuned up. And I should be back in business and ready for the next AITP event.
Of these, the Jetstream VHF/UHF Yagi was the most expensive and most frustrating. The assembly instructions were vague, the elements were colour-coded to confound colour-blind people like me, and it arrived with missing hardware. Not a single lock-washer was included, and a set screw was missing for the T-match. Within an hour of receiving it, I was on the phone with Jetstream in Ohio asking them to send the missing hardware. My call was handed to a guy that never gave his name, never apologised, and seemed highly confused. He obsessed over whether the antenna was VHF or UHF, as if that mattered with regard to lock-washers and set screws. I gave him the model number twice, and told him that it was a dual-band Yagi, which apparently is an unacceptable answer. He pointedly asked me to look at the package that the antenna came in and tell him if it said "UHF" or "VHF". He did this twice. I finally read the entire package to him verbatim, which he simply, flat-out, did not believe. Was I sure it was a Jetstream antenna? Yeah, I was. Finally, after much sighing, he took my address and said that he would send the missing hardware. It's been two weeks now, and it still isn't here. Instead, I went to the hardware store the day before AITP and got everything that I needed.
In total contrast, I had to contact Centerfire Antenna after AITP because I had lost one of the elements for my 1.25M Yagi at the event. A quick email to Ben there was immediately responded to on a Sunday, and he said that a replacement element would be sent the next day. He even followed up and notified me that it had been sent. And it actually arrived. No charge, no argument, no run-around. And the entire issue was entirely my fault.
So I'm back on 222 MHz again, after a couple of weeks. I've also ordered a new power supply so that I can use my 1.25M TH-9000 at full power, if need be. Today I'm going to work on the Jetstream Yagi and get it tuned up. And I should be back in business and ready for the next AITP event.
Saturday, 22 February 2014
1.25M FM antennae
Maybe you are excited about the 1.25M band, and what's in store for the metro. Maybe you just are thinking that 222 MHz is the only band that you don't have a radio for. You may be looking at a TYT TH-9000 1.25M mobile and thinking that you could afford that and make it work. Or you might have your eye on a TYT HT for the band that you could press into service as a mobile / base.
Previously, I looked at your rig options for the 1.25M (222 MHz) band. But you'll also need an antenna to make effective use of any of these radios.
I have an Anli tri-band mobile antenna that's about three feet long. It's about as good as a 1/4-wave on VHF, in terms of performance (specs aside). On 1.25M, though, it works very well. When I was using it as a mobile antenna, I received a lot of signal reports telling me of strong "picket fencing" while I was in motion. So I took it off the car and attached it to a mag-mount on my balcony. Though it's too conspicuous at my condo for daylight use, it makes a very good base antenna after nightfall. Obviously, "picket fencing" isn't an issue for this purpose. I've also used it indoors with very good results on local repeaters.
For mobile use, though, I'm looking at the Comet SSB-224 tri-band loaded whip. N0YNT (Matt) has been using this for a while without complaint, and he has a nice signal on the 1.25M band.
For monoband mobile or home use, however, Laird Technologies makes a (roughly $7) 1/4-wave NMO whip that's as simple as you can get. A mag-mount with NMO thread will let you use this whip inside on a metal surface that has about a foot of space to act as a ground plane. 1.25M is not as suitable as UHF is for interior antennae, however. It will still work, though.
For omnidirectional base station use, Centerfire Antenna offers a simple 1/4-wave ground-plane for $30 (plus $3 shipping). The vertical element is about a foot high, so it can also be used indoors in a closet or placed outside without unduly affecting the aesthetics of a home.
If a directional antenna is what you feel you need, Laird Technologies has a 3-element Yagi for around $90. This might be what you need if you want to operate simplex or only have one repeater that you want to reach. Centerfire also has a cheaper 3-element Yagi ($45 plus $3 shipping) for the band, which is what I use. Both of these can also be used as hand-held solutions, rather than being mounted, because of their relatively small size. I set mine on a tripod on my balcony, for example.
M-Squared also offers a five-element Yagi (222-5SS) for $89. If you really have a desire to spend some money, look at their 222XP30 for a "mere" $430.
Bear in mind that 1.25M FM isn't allowed hardly anywhere outside of North America, and there isn't much of an equivalent commercial market alongside of the amateur radio market. This means that radios and antennae for the 1.25M FM band are a definite speciality niche, and you won't find a wide variety of gear for the band like you do with two metres. Still, there are affordable options out there beyond a "rubber duck" for hams that want to make use of the band.
Commercial interests have their eye on the 1.25M amateur radio spectrum, and it's a lot easier for the FCC to justify selling it off to the highest bidder when the amateur radio community isn't using it. Any licensed ham can use the 222 MHz frequencies, so why not do your part to help save this band? An HT and a ground-plane antenna will serve you well on these frequencies, and 1.25M has great propagation for mobile use, too. Set up a simplex link with EchoLink and your 222 MHz radio to allow those without a radio to access the band. Let your local radio club know that it's worthwhile for them to investigate putting up a repeater for the band. And, most of all, actually get on there and use it.
Previously, I looked at your rig options for the 1.25M (222 MHz) band. But you'll also need an antenna to make effective use of any of these radios.
I have an Anli tri-band mobile antenna that's about three feet long. It's about as good as a 1/4-wave on VHF, in terms of performance (specs aside). On 1.25M, though, it works very well. When I was using it as a mobile antenna, I received a lot of signal reports telling me of strong "picket fencing" while I was in motion. So I took it off the car and attached it to a mag-mount on my balcony. Though it's too conspicuous at my condo for daylight use, it makes a very good base antenna after nightfall. Obviously, "picket fencing" isn't an issue for this purpose. I've also used it indoors with very good results on local repeaters.
For mobile use, though, I'm looking at the Comet SSB-224 tri-band loaded whip. N0YNT (Matt) has been using this for a while without complaint, and he has a nice signal on the 1.25M band.
For monoband mobile or home use, however, Laird Technologies makes a (roughly $7) 1/4-wave NMO whip that's as simple as you can get. A mag-mount with NMO thread will let you use this whip inside on a metal surface that has about a foot of space to act as a ground plane. 1.25M is not as suitable as UHF is for interior antennae, however. It will still work, though.
For omnidirectional base station use, Centerfire Antenna offers a simple 1/4-wave ground-plane for $30 (plus $3 shipping). The vertical element is about a foot high, so it can also be used indoors in a closet or placed outside without unduly affecting the aesthetics of a home.
If a directional antenna is what you feel you need, Laird Technologies has a 3-element Yagi for around $90. This might be what you need if you want to operate simplex or only have one repeater that you want to reach. Centerfire also has a cheaper 3-element Yagi ($45 plus $3 shipping) for the band, which is what I use. Both of these can also be used as hand-held solutions, rather than being mounted, because of their relatively small size. I set mine on a tripod on my balcony, for example.
M-Squared also offers a five-element Yagi (222-5SS) for $89. If you really have a desire to spend some money, look at their 222XP30 for a "mere" $430.
Bear in mind that 1.25M FM isn't allowed hardly anywhere outside of North America, and there isn't much of an equivalent commercial market alongside of the amateur radio market. This means that radios and antennae for the 1.25M FM band are a definite speciality niche, and you won't find a wide variety of gear for the band like you do with two metres. Still, there are affordable options out there beyond a "rubber duck" for hams that want to make use of the band.
Commercial interests have their eye on the 1.25M amateur radio spectrum, and it's a lot easier for the FCC to justify selling it off to the highest bidder when the amateur radio community isn't using it. Any licensed ham can use the 222 MHz frequencies, so why not do your part to help save this band? An HT and a ground-plane antenna will serve you well on these frequencies, and 1.25M has great propagation for mobile use, too. Set up a simplex link with EchoLink and your 222 MHz radio to allow those without a radio to access the band. Let your local radio club know that it's worthwhile for them to investigate putting up a repeater for the band. And, most of all, actually get on there and use it.
Tuesday, 14 January 2014
Experiments in local vertical VHF SSB
On Sunday (1/12), three of us tried to do two-metre simplex in SSB mode with vertical antennae. You may recall my previous post discussing this. It was not a glowing success, and we really didn't understand why.
N0YNT (Matt) and KD0UIH (Chuck) could work each other on 144.210, but I was more-or-less out of the conversation and below the noise level. UHF SSB operation on 432.200 was a failure for all involved.
Chuck and I had tried to do FM simplex on two metres before in November. I had expected it to go very well. After all, we were only 15 miles apart, and had 50W to work with. My reasoning was that, if I could reach a repeater in St. Paul with around five watts, I certainly should be able to reach Chuck in St. Paul with ten times that power.
And yet, I was wrong.
KD0UIH and I were unable to hear each other using VHF FM simplex. Instead, we had someone from the VHF .370 act as a relay, and we had to acknowledge that as a mysterious failure.
I didn't let the matter rest, though. There had to be some way to get simplex communications to work locally on VHF. Sure there was two-metre sideband, but that required a horizontal antenna, and we all had verticals. But we kept talking about it, and it dawned on us that we only needed a horizontal antenna to talk to other operators using a horizontal antenna. If everyone involved in the QSO was using a vertical antenna, then it should work. I was confident that a weak signal mode would succeed where FM's need for a strong signal had failed.
And yet, I was wrong.
My confidence had convinced me that I could get away with using a mag-mount dual-band 1/4-wave that tuned up to the SSB part of the band. It was a marginal antenna, but this was going to easy, so it didn't matter, right?
So last night (1/13), I had my very best VHF antenna mounted on my balcony after dark. I had confirmed that it tuned up on 144.210. I tried a few SSB transmissions, and found that it interfered with my TV reception, and created a little audio interference on the stereo. I shrugged and tuned around the local FM repeaters. I ran in to N0YNT and N0DSH (Frank) on the UHF .425, and we talked about the failure of the night before.
On a whim, I asked Matt if he was willing to try it again with the improved antenna on my end. He agreed, and we rolled up to 144.210 without a lot of expectation for success.
And yet, I was wrong.
This time, N0YNT came through clearly at a level of S8 from St. Paul! He gave me a similar report. Even better, KD0WZW (Pete) had been listening to the conversation on the .425 and he had come along for the ride. He gave Matt and I an S7 signal report from Lino Lakes, which is about what I had him at (maybe S6 at times). And all of us were using vertical antennae with a weak signal mode. The experiment was a success.
I guess that the problem was that I had chosen to use a lousy antenna for our first experiment. I had chalked the good signals between N0YNT and KD0UIH down to proximity, but the real factor was that they were both using decent antennae.
Due to the interference issues, I don't expect to do a lot of two-metre sideband work out of my place, vertical or otherwise. But it's something that I could set up as a portable or mobile option away from home.
This kind of thing isn't really compatible with the fading weak-signal two-metre work done by others around the State, because we are using vertical antennae. Yes, we've all heard stories of two-metre SSB QSOs using horizontal beams over long distances. None of us, however, have a horizontal antenna for the band. It's not practical for my location, and I'm happy with using a vertical considering that most other people don't have a two-metre horizontal antenna, either.
Just because I can't operate two-metre SSB out of my home, that doesn't preclude others from doing it, though. We basically just confirmed that it's possible for most hams to have simplex communications across the metro area with the vertical antenna that they already have. They need an all-mode radio, of course, and that means that an HT isn't going to do it. It's also different than the quiet of FM.
Still, for a Technician wishing to "upgrade" in the hobby, wouldn't local vertical VHF SSB be more practical than HF?
HF operation needs a lot of yard, sympathetic neighbours, big antennae, and high power. Local vertical VHF SSB, however, allows a ham to use the same J-pole or ground-plane that they already have, while allowing them to get away from repeaters. The problem is, however, that it requires enough other vertically-oriented hams to make it viable. Communication with the old, horizontally-polarised community is not going to work.
As with everything else on ham radio, activity draws activity. If it were to become known that four or five hams were meeting on 144.210 on vertical SSB, it would attract people for the novelty alone. Roundtables would form, and new hams might be persuaded to look at all-mode gear. Who knows? It might lead to local (or regional) PSK31 activity (which is quiet) with vertical polarisation. With voice-to-text apps on smart-phones, and apps like DroidPSK, it might catch on.
But I've been wrong about this stuff before.
N0YNT (Matt) and KD0UIH (Chuck) could work each other on 144.210, but I was more-or-less out of the conversation and below the noise level. UHF SSB operation on 432.200 was a failure for all involved.
Chuck and I had tried to do FM simplex on two metres before in November. I had expected it to go very well. After all, we were only 15 miles apart, and had 50W to work with. My reasoning was that, if I could reach a repeater in St. Paul with around five watts, I certainly should be able to reach Chuck in St. Paul with ten times that power.
And yet, I was wrong.
KD0UIH and I were unable to hear each other using VHF FM simplex. Instead, we had someone from the VHF .370 act as a relay, and we had to acknowledge that as a mysterious failure.
I didn't let the matter rest, though. There had to be some way to get simplex communications to work locally on VHF. Sure there was two-metre sideband, but that required a horizontal antenna, and we all had verticals. But we kept talking about it, and it dawned on us that we only needed a horizontal antenna to talk to other operators using a horizontal antenna. If everyone involved in the QSO was using a vertical antenna, then it should work. I was confident that a weak signal mode would succeed where FM's need for a strong signal had failed.
And yet, I was wrong.
My confidence had convinced me that I could get away with using a mag-mount dual-band 1/4-wave that tuned up to the SSB part of the band. It was a marginal antenna, but this was going to easy, so it didn't matter, right?
So last night (1/13), I had my very best VHF antenna mounted on my balcony after dark. I had confirmed that it tuned up on 144.210. I tried a few SSB transmissions, and found that it interfered with my TV reception, and created a little audio interference on the stereo. I shrugged and tuned around the local FM repeaters. I ran in to N0YNT and N0DSH (Frank) on the UHF .425, and we talked about the failure of the night before.
On a whim, I asked Matt if he was willing to try it again with the improved antenna on my end. He agreed, and we rolled up to 144.210 without a lot of expectation for success.
And yet, I was wrong.
This time, N0YNT came through clearly at a level of S8 from St. Paul! He gave me a similar report. Even better, KD0WZW (Pete) had been listening to the conversation on the .425 and he had come along for the ride. He gave Matt and I an S7 signal report from Lino Lakes, which is about what I had him at (maybe S6 at times). And all of us were using vertical antennae with a weak signal mode. The experiment was a success.
I guess that the problem was that I had chosen to use a lousy antenna for our first experiment. I had chalked the good signals between N0YNT and KD0UIH down to proximity, but the real factor was that they were both using decent antennae.
Due to the interference issues, I don't expect to do a lot of two-metre sideband work out of my place, vertical or otherwise. But it's something that I could set up as a portable or mobile option away from home.
This kind of thing isn't really compatible with the fading weak-signal two-metre work done by others around the State, because we are using vertical antennae. Yes, we've all heard stories of two-metre SSB QSOs using horizontal beams over long distances. None of us, however, have a horizontal antenna for the band. It's not practical for my location, and I'm happy with using a vertical considering that most other people don't have a two-metre horizontal antenna, either.
Just because I can't operate two-metre SSB out of my home, that doesn't preclude others from doing it, though. We basically just confirmed that it's possible for most hams to have simplex communications across the metro area with the vertical antenna that they already have. They need an all-mode radio, of course, and that means that an HT isn't going to do it. It's also different than the quiet of FM.
Still, for a Technician wishing to "upgrade" in the hobby, wouldn't local vertical VHF SSB be more practical than HF?
HF operation needs a lot of yard, sympathetic neighbours, big antennae, and high power. Local vertical VHF SSB, however, allows a ham to use the same J-pole or ground-plane that they already have, while allowing them to get away from repeaters. The problem is, however, that it requires enough other vertically-oriented hams to make it viable. Communication with the old, horizontally-polarised community is not going to work.
As with everything else on ham radio, activity draws activity. If it were to become known that four or five hams were meeting on 144.210 on vertical SSB, it would attract people for the novelty alone. Roundtables would form, and new hams might be persuaded to look at all-mode gear. Who knows? It might lead to local (or regional) PSK31 activity (which is quiet) with vertical polarisation. With voice-to-text apps on smart-phones, and apps like DroidPSK, it might catch on.
But I've been wrong about this stuff before.
Saturday, 10 August 2013
Dreaming up situations
Maybe you're thinking about getting a licence, and you're looking at those really cheap Chinese hand-helds on the web today and thinking how really easy it would be to talk to people in your area -- outside of an emergency, of course. How do you go about doing that?
Sure, we can look at hamradioschool's advice on the subject. Remember, the guy in his story had a choice. W0STU just offered options. Got that disclaimer? The guy in his story also had an attic, lived in a mountainous area with a menace of forest fires, and could barely reach the local repeater with his "rubber duck" antenna. BTW, we should stick with W0STU's terminology and always refer to a rubber duck as a "really convenient, crappy" antenna. A rubber duck, especially on a dual-band radio, is "crappy" -- but it often will hit repeaters in an urban or suburban setting just fine. Some people may be surprised to find that not everyone lives in Colorado, or that the realities faced by an urban ham are different from those of a rural ham. Those people would mostly be described as naive and provincial, of course.
See, I live in Plymouth, MN. It's a Northwest suburb of Minneapolis. Forest fires aren't a problem. I don't have an attic, because I live in a condo. The HOA where I live doesn't allow any exterior antenna that they can recognise as such. Before that, I lived in an apartment. My landlord wouldn't allow an antenna, and pretty much none of them will. There's concerns about lightning and liability. There are also issues about damaging the roof during an installation and drilling holes for the cable, and other stuff along those lines. It's pretty easy to say "No" if you're a landlord. Maybe people like W0STU don't live in that world, or they think that uttering the word "emergency" magically changes minds. In my world, the word "eviction" or "fine" is pretty persuasive.
So, before I go into some suggestions, I just want to point out (as W0STU does) that these are only possibilities. I don't control your life, and you can do whatever you want. Clear now? That makes a big difference, I guess. Maybe your situation is different than mine. If you can set up a 50-foot tower, or the closest repeater is 50 miles away, these solutions might not be for you. Hell, I'll just say it: they aren't for you, okay?
If you live in a suburban or urban setting, you probably have repeaters (either VHF or UHF) nearby. You might have a repeater 7.5 miles away, as W0STU's buddy does, but have terrain interfering. Oddly, one thing that you don't do is work simplex, as everyone in K0NR's world does. You might want to reach other repeaters where the cool people hang out, but they are farther away. You need an external antenna beyond the "really convenient, crappy" rubber duck antenna that came with your radio. I know that confuses you, but there are inexpensive and really easy options.
The one that I settled on right away is the mag mount antenna. You can take it off your car and use it inside, too. I have a balcony that has a sheet steel cap, and I slap the mag mount antenna on that. They are (well) under $30 and come with cable. Another option is to use the mag mount antenna inside. Yeah, W0STU doesn't mention this, because it's a bit "ghetto" for his tastes, I guess. You can slap a mag mount antenna on top of a metal file cabinet, refrigerator, baseboard heater -- whatever is magnetic. I used a metal paint can for GMRS for years. You really want something that's at least 2-1/2 feet long, though. A steel ironing board, a metal shelf, the lid from a steel drum, a steel tire rim -- these will all work. The metal acts as a "ground plane" for the mag mount antenna, effectively making it larger than it really is electrically. With a "really convenient, crappy" rubber duck antenna, your body is the ground plane. You aren't made of iron.
I bought this one. You can get a Tram 1185 from other places, too. You can also get a separate mag mount without an antenna, and get an antenna to attach to it. There is also the Nagoya UT-108, which has cheap cable but is very unobtrusive. I used this for months and my HOA had no issue with it. I told them it was for my cell phone. Also, look at some Jetstream mag mount antennae. You may need an an adapter from your radio to the antenna connection, but those are cheap. Something like this will let you use your Chinese hand-held with a PL-259 antenna. Simple adapters cost about $3 without the cable between them. The advantage here is that you can use your hand-held (HT) in the car and the house for less money than W0STU's "thrifty" alternative that sits in your (non-existent) attic.
You could also look at something like this. Now, W0STU's buddy settles on a J-pole, but it's a solid one that he puts in his attic. This is different. And don't be fazed if the item isn't available any more. There are other people constantly selling these dual-band J-poles because they are easy to make. Search for j-pole. The one that I linked to is 57" long. That's less than five feet. It also has 16 feet of coaxial cable for you to run to your radio. That cable is not the highest quality, but it's only 16 feet long. What can you do with something like this? Drop it out of a second-story window. Or stick it on to a six-foot length of PVC pipe, paint it the same colour as the pipe, stick a flag on the end of the pipe, and erect it on your balcony or outside of an upper-story window. It's not an antenna; it's a flag. Got a problem with that? Obviously, height is the key, but you can get good results putting that pipe/flag on your deck, too. The main thing is the length and the fact that it's outside.
All of these are better options than your "really convenient, crappy" rubber duck antenna. They aren't K0NR's $120 ground plane, nor W0STU's $40 cheap alternative without cable. They will get you on the air, they will survive poor conditions, and they are flexible. But if your "really convenient, crappy" rubber duck antenna works for your home, then just look at a mag mount option for your car. And, if you don't have a car, a cheap mag mount will be useful most places that you go. Anywhere with something steel will be your mount; even a steel railing or bench. A parked car that doesn't belong to you is your potential mount. That steel manhole cover is your mount. That J-pole can be tossed over a tree branch at the park, or hung off a bridge.
Isn't something like that more useful for an emergency than something stuck in your attic? Maybe ask some guy in Colorado first.
The bottom line is that I can dig up some situation where my solutions don't work. If you live in that situation, and have no ability to move outside of it, then you should consider what W0STU says very seriously. Or abandon ham radio.
For some weird reason, it keeps coming back to "emergencies". When you go to a sporting goods store, does the salesman push a particular rod and reel as an alternative for emergencies when the stores won't sell fish?
There's this weird fear-mongering pervading ham radio. If there really is an emergency, and you pull out your roll-up J-pole and Chinese HT, I don't think that a lot people are going to care if you're licensed in the first place. But it's not hard to get licensed, so we have to put other barriers in place -- things that cost money, for example. Because it really isn't about emergency communications. It's part and parcel of the stupid class/generational divide that needs to keep the "riff-raff" away from the "pure" people. You've gotta own a home, and spend a certain amount of money, and live your life a certain way if you're gonna be an amateur radio operator. That's how we keep it clean. Otherwise, "the wrong sort" will try to intrude. See, everybody's eager to talk about some old guy about his health problems, so we have to weed out the bad guys. Money works pretty well as a barrier. Let's invent ridiculous scenarios requiring more and more money if you want to be taken seriously by people who will never, ever take you seriously anyway.
I am proof that, for under $100, you can get on the air and be a ham for life. Spend some time and find some people that don't hate the world or live in 1955. Get them on the air. Sure, it'll piss off the people already there. Tell 'em K0NR sent you -- for the emergencies.
I'm just adding this on here. Bob noted before that he has "promoted" Chinese hand-held radios. I'm sure that he considers the article that I linked to as an example of him "promoting" Chinese HTs. W0STU does mention a person using one, but the entire article is about how it failed W0STU's buddy Randy, and begins and ends with W0STU's buddy's plans to get a "real" radio, which K0NR encourages. His other "promotions" include referencing discredited measurements of Chinese HTs. Over-driving the input of a spectrum analyser can make any radio look horrible.
Maybe Bob can show up here again and tell us about his "promotion" of Chinese HTs. Showing an example of someone unhappy with one isn't "promoting" it, though. I don't have an agenda. My job isn't to get you to fit into the crusty world of elderly hams, and of finding ways to win their constipated assent of your rig. If you want to spend $600 on a VHF/UHF setup, go ahead. If you have room for huge antennas, put them up. If you want to get on HF, then do so. None of those things relate to anything in my world, though.
You can get on the air without spending a lot of money in an urban or suburban situation. You can go fishing with a $25 combo, or some string and a safety pin. You won't impress anyone with those options, as you can imagine. There will 'experts' telling you that you need to spend a lot of money, and they won't like it. Why would you need them, if you can do it simply and cheaply, after all? So you talk about "emergencies". You move away from the enjoyment of actually fishing or talking, and focus on the exceptions where expensive stuff is superior. And, pretty soon, everything is an emergency.
Sure, we can look at hamradioschool's advice on the subject. Remember, the guy in his story had a choice. W0STU just offered options. Got that disclaimer? The guy in his story also had an attic, lived in a mountainous area with a menace of forest fires, and could barely reach the local repeater with his "rubber duck" antenna. BTW, we should stick with W0STU's terminology and always refer to a rubber duck as a "really convenient, crappy" antenna. A rubber duck, especially on a dual-band radio, is "crappy" -- but it often will hit repeaters in an urban or suburban setting just fine. Some people may be surprised to find that not everyone lives in Colorado, or that the realities faced by an urban ham are different from those of a rural ham. Those people would mostly be described as naive and provincial, of course.
See, I live in Plymouth, MN. It's a Northwest suburb of Minneapolis. Forest fires aren't a problem. I don't have an attic, because I live in a condo. The HOA where I live doesn't allow any exterior antenna that they can recognise as such. Before that, I lived in an apartment. My landlord wouldn't allow an antenna, and pretty much none of them will. There's concerns about lightning and liability. There are also issues about damaging the roof during an installation and drilling holes for the cable, and other stuff along those lines. It's pretty easy to say "No" if you're a landlord. Maybe people like W0STU don't live in that world, or they think that uttering the word "emergency" magically changes minds. In my world, the word "eviction" or "fine" is pretty persuasive.
So, before I go into some suggestions, I just want to point out (as W0STU does) that these are only possibilities. I don't control your life, and you can do whatever you want. Clear now? That makes a big difference, I guess. Maybe your situation is different than mine. If you can set up a 50-foot tower, or the closest repeater is 50 miles away, these solutions might not be for you. Hell, I'll just say it: they aren't for you, okay?
If you live in a suburban or urban setting, you probably have repeaters (either VHF or UHF) nearby. You might have a repeater 7.5 miles away, as W0STU's buddy does, but have terrain interfering. Oddly, one thing that you don't do is work simplex, as everyone in K0NR's world does. You might want to reach other repeaters where the cool people hang out, but they are farther away. You need an external antenna beyond the "really convenient, crappy" rubber duck antenna that came with your radio. I know that confuses you, but there are inexpensive and really easy options.
The one that I settled on right away is the mag mount antenna. You can take it off your car and use it inside, too. I have a balcony that has a sheet steel cap, and I slap the mag mount antenna on that. They are (well) under $30 and come with cable. Another option is to use the mag mount antenna inside. Yeah, W0STU doesn't mention this, because it's a bit "ghetto" for his tastes, I guess. You can slap a mag mount antenna on top of a metal file cabinet, refrigerator, baseboard heater -- whatever is magnetic. I used a metal paint can for GMRS for years. You really want something that's at least 2-1/2 feet long, though. A steel ironing board, a metal shelf, the lid from a steel drum, a steel tire rim -- these will all work. The metal acts as a "ground plane" for the mag mount antenna, effectively making it larger than it really is electrically. With a "really convenient, crappy" rubber duck antenna, your body is the ground plane. You aren't made of iron.
I bought this one. You can get a Tram 1185 from other places, too. You can also get a separate mag mount without an antenna, and get an antenna to attach to it. There is also the Nagoya UT-108, which has cheap cable but is very unobtrusive. I used this for months and my HOA had no issue with it. I told them it was for my cell phone. Also, look at some Jetstream mag mount antennae. You may need an an adapter from your radio to the antenna connection, but those are cheap. Something like this will let you use your Chinese hand-held with a PL-259 antenna. Simple adapters cost about $3 without the cable between them. The advantage here is that you can use your hand-held (HT) in the car and the house for less money than W0STU's "thrifty" alternative that sits in your (non-existent) attic.
You could also look at something like this. Now, W0STU's buddy settles on a J-pole, but it's a solid one that he puts in his attic. This is different. And don't be fazed if the item isn't available any more. There are other people constantly selling these dual-band J-poles because they are easy to make. Search for j-pole. The one that I linked to is 57" long. That's less than five feet. It also has 16 feet of coaxial cable for you to run to your radio. That cable is not the highest quality, but it's only 16 feet long. What can you do with something like this? Drop it out of a second-story window. Or stick it on to a six-foot length of PVC pipe, paint it the same colour as the pipe, stick a flag on the end of the pipe, and erect it on your balcony or outside of an upper-story window. It's not an antenna; it's a flag. Got a problem with that? Obviously, height is the key, but you can get good results putting that pipe/flag on your deck, too. The main thing is the length and the fact that it's outside.
All of these are better options than your "really convenient, crappy" rubber duck antenna. They aren't K0NR's $120 ground plane, nor W0STU's $40 cheap alternative without cable. They will get you on the air, they will survive poor conditions, and they are flexible. But if your "really convenient, crappy" rubber duck antenna works for your home, then just look at a mag mount option for your car. And, if you don't have a car, a cheap mag mount will be useful most places that you go. Anywhere with something steel will be your mount; even a steel railing or bench. A parked car that doesn't belong to you is your potential mount. That steel manhole cover is your mount. That J-pole can be tossed over a tree branch at the park, or hung off a bridge.
Isn't something like that more useful for an emergency than something stuck in your attic? Maybe ask some guy in Colorado first.
The bottom line is that I can dig up some situation where my solutions don't work. If you live in that situation, and have no ability to move outside of it, then you should consider what W0STU says very seriously. Or abandon ham radio.
For some weird reason, it keeps coming back to "emergencies". When you go to a sporting goods store, does the salesman push a particular rod and reel as an alternative for emergencies when the stores won't sell fish?
There's this weird fear-mongering pervading ham radio. If there really is an emergency, and you pull out your roll-up J-pole and Chinese HT, I don't think that a lot people are going to care if you're licensed in the first place. But it's not hard to get licensed, so we have to put other barriers in place -- things that cost money, for example. Because it really isn't about emergency communications. It's part and parcel of the stupid class/generational divide that needs to keep the "riff-raff" away from the "pure" people. You've gotta own a home, and spend a certain amount of money, and live your life a certain way if you're gonna be an amateur radio operator. That's how we keep it clean. Otherwise, "the wrong sort" will try to intrude. See, everybody's eager to talk about some old guy about his health problems, so we have to weed out the bad guys. Money works pretty well as a barrier. Let's invent ridiculous scenarios requiring more and more money if you want to be taken seriously by people who will never, ever take you seriously anyway.
I am proof that, for under $100, you can get on the air and be a ham for life. Spend some time and find some people that don't hate the world or live in 1955. Get them on the air. Sure, it'll piss off the people already there. Tell 'em K0NR sent you -- for the emergencies.
I'm just adding this on here. Bob noted before that he has "promoted" Chinese hand-held radios. I'm sure that he considers the article that I linked to as an example of him "promoting" Chinese HTs. W0STU does mention a person using one, but the entire article is about how it failed W0STU's buddy Randy, and begins and ends with W0STU's buddy's plans to get a "real" radio, which K0NR encourages. His other "promotions" include referencing discredited measurements of Chinese HTs. Over-driving the input of a spectrum analyser can make any radio look horrible.
Maybe Bob can show up here again and tell us about his "promotion" of Chinese HTs. Showing an example of someone unhappy with one isn't "promoting" it, though. I don't have an agenda. My job isn't to get you to fit into the crusty world of elderly hams, and of finding ways to win their constipated assent of your rig. If you want to spend $600 on a VHF/UHF setup, go ahead. If you have room for huge antennas, put them up. If you want to get on HF, then do so. None of those things relate to anything in my world, though.
You can get on the air without spending a lot of money in an urban or suburban situation. You can go fishing with a $25 combo, or some string and a safety pin. You won't impress anyone with those options, as you can imagine. There will 'experts' telling you that you need to spend a lot of money, and they won't like it. Why would you need them, if you can do it simply and cheaply, after all? So you talk about "emergencies". You move away from the enjoyment of actually fishing or talking, and focus on the exceptions where expensive stuff is superior. And, pretty soon, everything is an emergency.
Sunday, 28 July 2013
Antenna trials and VHF repeaters
I played with the radios on Friday for a few hours. I only work a half-day on Friday, because I work four 9-hour shifts the rest of the week. So, when I got home and took care of a few minor tasks, I decided to spend a little time on the radio. I put my new 6 meter J-pole on my new 13-foot telescoping mast and tried a few configurations to eliminate the interference and keep the SWR low. The band wasn't particularly awesome, but I still hope to be able to work it without the stereo picking up the signal, so I need to figure out the best way to set up the antenna. The mast at full height can suspend the J-pole at the coax end, and the free end is attached to the other side of the balcony with a string held by a magnet. This gets me a horizontally-polarised antenna, though it faces to the East and the West is blocked by the building. The SWR is perfect at the low end, but not great at FM frequencies. Unfortunately, this arrangement still gets transmit audio in the stereo. Anything over 20 watts RF output comes through clean and strong on the stereo - and, I must assume, the neighbour's electronics. A coaxial RF choke didn't help that much on six meters, but it did on ten meters. I tried a few other J-pole arrangements, but none were the perfect situation. Having the J-pole vertical and pulled somewhat away from the metal mast worked great on FM.
With the re-purposed Sirio magnetic mount converted to NMO, I tried out the 10 meter vertical. The Sirio mount has a much better ground-plane, and the coaxial RF choke works well on HF, so there's hardly any interference and the SWR is perfect. I am still thinking about getting a second 10 meter "hamstick" and setting up a horizontal dipole on the new mast, because that would let me get above the building and rotated to the north/south. I still think that a horizontal antenna is going to interfere less, because I could use a balun. The problem with this arrangement is that it's not easy to attach two big antennae to the mast when it's down and I'm restricted to the space on the balcony. And, obviously, this is no "stealth" antenna. It's night-time use only, and with calm winds. For now, though, the vertical whip is working well
So, I took off the NMO adapter and dusted off my Nagoya MAG-79EL-3W, which has a UHF mount. Normally, I don't use it because its size makes it conspicuous, but I had already blown that for the day by setting up the 13-foot mast and the 10 meter vertical whip in broad daylight. Now that the Browning dual-band is on my car, I don't have a really good antenna for home use. Instead, I'm using the Nagoya NL-R2 with the PL-259 Sirio mount. It has decent SWR on both bands (though better on VHF), and is low-profile, but it doesn't have great range. The 79El-3W has great range, but really doesn't tune up well on UHF, so I sat down for the late Friday afternoon to work some of the more distant VHF repeaters in the area that I normally ignore.
I threw out my sign a few times on the VHF repeater (145.13-, 110.9) in Hudson, WI. Nobody was biting, though. I always wonder about repeaters like this -- who uses them? You're within the range of the UHF repeater in River Falls (which is linked to the whole State) and on the edge of the Twin Cities repeater (also linked to the entire State of Wisconsin). Maybe you just don't like UHF. There's really not a WINET VHF repeater near Hudson, I suppose. Still, you would think that there would be commuters or boaters or locals -- someone actually using these repeaters -- to justify their existence. When it breaks or needs to be taken down for a water tower replacement (or whatever), that will probably be the end of it. WINET would be smart to take it over, in that case, and add it to their VHF network. It covers the St. Croix boating and the I-94 traffic, and would reach into St. Paul easily.
I also tried the Northfield (147.360+, 136.5) repeater, without much expectation. Nothing there on a late Friday afternoon. I think this repeater is technically in Hampton, MN and is run by just one guy instead of a club. Certainly, if someone in the metro had even a mediocre 2 meter ground plane and 10-15 watts, they could work this repeater regularly. As it was, I had a mobile antenna on a mag mount and 20 W and I hit it without any trouble from Plymouth, MN.
The Becker VHF repeater is still down, though it was supposed to be up a week after the Fourth of July. That's the conversation that I heard on the repeater between the trustee and some radio club or organisation that was considering a grant to get the whole network up and running. The VHF repeater would really allow the network to reach into the metro. In my car, driving around Plymouth, the Becker UHF repeater struggles to break squelch under the best conditions. If you could reliably reach that network from the metro, however, you have coverage from Mille Lacs down to Glencoe on UHF and out to Willmar. There are four UHF repeaters linked together by Echolink: Becker, Avon, Litchfield, and Little Falls. This means that, if you can reach one of them, you can talk to anyone within reach of any of the other repeaters. Of course, the repeaters are accessible by Echolink from anywhere. The area covered is a big recreational area, as well as covering the Interstate traffic, and rural farmland. This means that you can be reached while out in the boat, or on the freeway, camping, etc. from the city on Echolink. And, yes, a cell phone can do that. The idea, at least in my mind, is that you can get people who own radios to actually use them when they out by making coverage available in those areas. The trouble with repeater coverage in rural areas is that you have fewer people -- a smaller pool of people that have the time and inclination to talk on the radio. By increasing that pool of potential users by linking, you now increase the odds that two people will be on the repeater at once. Nothing can actually make them talk, of course, which seems to be a big part of the problem. Ideally, though, a metro area ham could still keep in touch with ham buddies at home while he spends the weekend at the lake or goes camping. That might encourage them to bring their radio along.
I was going to take a shot at a couple of SE metro repeaters, but instead I decided to try the Ramsey (145.37-, 107.2) VHF repeater, which I hadn't been able to get in my car. So I threw out my call sign and got someone immediately. It was KA0SDU (Dan), who I had spoken with back in March when I first discovered the .370 repeater. I paused for a moment to check my log, and sure enough, he was in Rosemount. I asked him what he was doing on the Ramsey repeater, as I thought he hung out at the .370. I was really surprised to hear him come back with, "This is the .370 repeater".
Apparently, when I was programming my FT-897D for the repeaters, I mis-labeled that preset. Instead, I was set up for the Minneapolis .370 (145.370-, 107.2) repeater and tagged it as "Ramsey". The MPL370 (as my HT has it marked), is (I've been told) on the top of the IDS tower for awesome coverage. I've never put that coverage to the test myself, but I've spoken to people in Rosemount and Farmington. Farmington is around 40 miles, after all. Hudson is about that far away, and Forest Lake, Elk River, and Delano are in that radius, too. The .370 is one of the prime VHF repeaters in the metro, and if was multi-receive it would blow away the others.
The others would be the TCRC's 147.21, the Oakdale .850 (146.850-), the TCFMC's .760 (146.76-), and the HandiHam .450, in no particular order.
The HandiHam network is especially impressive, in my opinion. Not only is it on Echolink and accessed from other countries commonly, it also is cross-band (you can talk on UHF, VHF, and 220 at the same time), and links up to other repeaters in Chaska (on UHF), Arden Hills (on 220), Albert Lea (on VHF), Ellendale (near Rochester) on UHF and 220, and out to Rapid City, SD (on VHF). There are also plans for a 10 meter FM repeater on 29.660, though I don't know how that will work. 10 meter FM is only allowed for General Class licences and above, so linking it to the rest of the network would most likely be illegal. Still, it would be the only 10 meter FM repeater in the metro area and would have great range.
TCFMC's VHF repeater at .760 (W0EF) also has Echolink, though it's not often used and hadn't been logged in for about four months until I mentioned it on the club forum. I've never put the "seven six" to the test. I've spoken to someone in Delano on it, but that's only 20 miles. It may very well be a case of hype, much like the range of the UHF repeater ("dot one"). I listed it mostly because of the traffic level - which is also not awesome.
The Oakdale .850 has several receive sites. I know that one of them are around Scandia, and I was able to keep in touch with the repeater almost up to North Branch because of this. I've heard that this used to be the focal point for most repeater activity in the metro "back in the day", but now it's kind of quiet.
Actually, all of these repeaters except for the HandiHam network are pretty quiet. If you can get someone to talk to you, however, a small crowd will emerge quickly. There are a lot of people, apparently, who scan the repeaters and like to listen more than they like to talk. They don't have a strong loyalty to any repeater, and they won't take the initiative to start a conversation. But once a conversation has started, people will jump in with tangential remarks, contributions, or relevant experiences. This, in turn, gets hams across the metro listening as their scans stop and they hear someone that they know toss in their two cents. And, more people then want to join in. It can snowball dramatically, depending on how interesting the discussion is, the time of day, and the coverage of the repeater.
As it so happened, I had stumbled on to the .370 (wide coverage), found someone to talk to right away (KA0SDU), during the start of the evening drive time on a Friday (good time of day), and I was ready to talk. And, so it unfolded. I'll relate it all in my next post.
With the re-purposed Sirio magnetic mount converted to NMO, I tried out the 10 meter vertical. The Sirio mount has a much better ground-plane, and the coaxial RF choke works well on HF, so there's hardly any interference and the SWR is perfect. I am still thinking about getting a second 10 meter "hamstick" and setting up a horizontal dipole on the new mast, because that would let me get above the building and rotated to the north/south. I still think that a horizontal antenna is going to interfere less, because I could use a balun. The problem with this arrangement is that it's not easy to attach two big antennae to the mast when it's down and I'm restricted to the space on the balcony. And, obviously, this is no "stealth" antenna. It's night-time use only, and with calm winds. For now, though, the vertical whip is working well
So, I took off the NMO adapter and dusted off my Nagoya MAG-79EL-3W, which has a UHF mount. Normally, I don't use it because its size makes it conspicuous, but I had already blown that for the day by setting up the 13-foot mast and the 10 meter vertical whip in broad daylight. Now that the Browning dual-band is on my car, I don't have a really good antenna for home use. Instead, I'm using the Nagoya NL-R2 with the PL-259 Sirio mount. It has decent SWR on both bands (though better on VHF), and is low-profile, but it doesn't have great range. The 79El-3W has great range, but really doesn't tune up well on UHF, so I sat down for the late Friday afternoon to work some of the more distant VHF repeaters in the area that I normally ignore.
I threw out my sign a few times on the VHF repeater (145.13-, 110.9) in Hudson, WI. Nobody was biting, though. I always wonder about repeaters like this -- who uses them? You're within the range of the UHF repeater in River Falls (which is linked to the whole State) and on the edge of the Twin Cities repeater (also linked to the entire State of Wisconsin). Maybe you just don't like UHF. There's really not a WINET VHF repeater near Hudson, I suppose. Still, you would think that there would be commuters or boaters or locals -- someone actually using these repeaters -- to justify their existence. When it breaks or needs to be taken down for a water tower replacement (or whatever), that will probably be the end of it. WINET would be smart to take it over, in that case, and add it to their VHF network. It covers the St. Croix boating and the I-94 traffic, and would reach into St. Paul easily.
I also tried the Northfield (147.360+, 136.5) repeater, without much expectation. Nothing there on a late Friday afternoon. I think this repeater is technically in Hampton, MN and is run by just one guy instead of a club. Certainly, if someone in the metro had even a mediocre 2 meter ground plane and 10-15 watts, they could work this repeater regularly. As it was, I had a mobile antenna on a mag mount and 20 W and I hit it without any trouble from Plymouth, MN.
The Becker VHF repeater is still down, though it was supposed to be up a week after the Fourth of July. That's the conversation that I heard on the repeater between the trustee and some radio club or organisation that was considering a grant to get the whole network up and running. The VHF repeater would really allow the network to reach into the metro. In my car, driving around Plymouth, the Becker UHF repeater struggles to break squelch under the best conditions. If you could reliably reach that network from the metro, however, you have coverage from Mille Lacs down to Glencoe on UHF and out to Willmar. There are four UHF repeaters linked together by Echolink: Becker, Avon, Litchfield, and Little Falls. This means that, if you can reach one of them, you can talk to anyone within reach of any of the other repeaters. Of course, the repeaters are accessible by Echolink from anywhere. The area covered is a big recreational area, as well as covering the Interstate traffic, and rural farmland. This means that you can be reached while out in the boat, or on the freeway, camping, etc. from the city on Echolink. And, yes, a cell phone can do that. The idea, at least in my mind, is that you can get people who own radios to actually use them when they out by making coverage available in those areas. The trouble with repeater coverage in rural areas is that you have fewer people -- a smaller pool of people that have the time and inclination to talk on the radio. By increasing that pool of potential users by linking, you now increase the odds that two people will be on the repeater at once. Nothing can actually make them talk, of course, which seems to be a big part of the problem. Ideally, though, a metro area ham could still keep in touch with ham buddies at home while he spends the weekend at the lake or goes camping. That might encourage them to bring their radio along.
I was going to take a shot at a couple of SE metro repeaters, but instead I decided to try the Ramsey (145.37-, 107.2) VHF repeater, which I hadn't been able to get in my car. So I threw out my call sign and got someone immediately. It was KA0SDU (Dan), who I had spoken with back in March when I first discovered the .370 repeater. I paused for a moment to check my log, and sure enough, he was in Rosemount. I asked him what he was doing on the Ramsey repeater, as I thought he hung out at the .370. I was really surprised to hear him come back with, "This is the .370 repeater".
Apparently, when I was programming my FT-897D for the repeaters, I mis-labeled that preset. Instead, I was set up for the Minneapolis .370 (145.370-, 107.2) repeater and tagged it as "Ramsey". The MPL370 (as my HT has it marked), is (I've been told) on the top of the IDS tower for awesome coverage. I've never put that coverage to the test myself, but I've spoken to people in Rosemount and Farmington. Farmington is around 40 miles, after all. Hudson is about that far away, and Forest Lake, Elk River, and Delano are in that radius, too. The .370 is one of the prime VHF repeaters in the metro, and if was multi-receive it would blow away the others.
The others would be the TCRC's 147.21, the Oakdale .850 (146.850-), the TCFMC's .760 (146.76-), and the HandiHam .450, in no particular order.
The HandiHam network is especially impressive, in my opinion. Not only is it on Echolink and accessed from other countries commonly, it also is cross-band (you can talk on UHF, VHF, and 220 at the same time), and links up to other repeaters in Chaska (on UHF), Arden Hills (on 220), Albert Lea (on VHF), Ellendale (near Rochester) on UHF and 220, and out to Rapid City, SD (on VHF). There are also plans for a 10 meter FM repeater on 29.660, though I don't know how that will work. 10 meter FM is only allowed for General Class licences and above, so linking it to the rest of the network would most likely be illegal. Still, it would be the only 10 meter FM repeater in the metro area and would have great range.
TCFMC's VHF repeater at .760 (W0EF) also has Echolink, though it's not often used and hadn't been logged in for about four months until I mentioned it on the club forum. I've never put the "seven six" to the test. I've spoken to someone in Delano on it, but that's only 20 miles. It may very well be a case of hype, much like the range of the UHF repeater ("dot one"). I listed it mostly because of the traffic level - which is also not awesome.
The Oakdale .850 has several receive sites. I know that one of them are around Scandia, and I was able to keep in touch with the repeater almost up to North Branch because of this. I've heard that this used to be the focal point for most repeater activity in the metro "back in the day", but now it's kind of quiet.
Actually, all of these repeaters except for the HandiHam network are pretty quiet. If you can get someone to talk to you, however, a small crowd will emerge quickly. There are a lot of people, apparently, who scan the repeaters and like to listen more than they like to talk. They don't have a strong loyalty to any repeater, and they won't take the initiative to start a conversation. But once a conversation has started, people will jump in with tangential remarks, contributions, or relevant experiences. This, in turn, gets hams across the metro listening as their scans stop and they hear someone that they know toss in their two cents. And, more people then want to join in. It can snowball dramatically, depending on how interesting the discussion is, the time of day, and the coverage of the repeater.
As it so happened, I had stumbled on to the .370 (wide coverage), found someone to talk to right away (KA0SDU), during the start of the evening drive time on a Friday (good time of day), and I was ready to talk. And, so it unfolded. I'll relate it all in my next post.