VHF tropo propagation gets crazy

  I had Friday off of work, so I got up early to take advantage of the tropospheric ducting that affects VHF and UHF frequencies. Over the past few weeks, I've been watching the real-time propagation maps that use APRS stations and gateways as beacons to gather data on how far signals are reaching in a particular area. I noticed a clear pattern: propagation was best in the morning, and it deteriorated as the day went on. 

An example of a great propagation map

   VHF / UHF aren't tied to solar activity like HF is. Instead of space weather, terrestrial weather creates favourable tropospheric propagation. And when conditions are good, even stations such as mine can reach much further than they can normally. 

  The first thing that I did was set my three-element tape measure Yagi to horizontal for a shot at two-metre SSB. Mostly, I was working with CW to make the best of the 50W power limitation on my FT-897D. While I actually heard three CW stations, they didn't respond to me. I heard local K0AD (Alan) on SSB, but he didn't come back, either. Next, I tried some UHF CW without luck. After a couple of hours, I switched the Yagi to vertical and began to try out some fairly distant FM repeaters. 

  With the beam (and the improved conditions), I reached the Baldwin repeater in Wisconsin easily. Good so far. Then I moved over to the Balsam Lake 147.195+ repeater, where I found K0JCR (Joe). It's about 60 miles to the Balsam Lake machine from my place in Plymouth, but I was quite surprised to learn that Joe was coming in from St. Peter! That's over 100 miles from Balsam Lake. We tried to QSY to 146.520 for FM simplex, but that didn't work out. There were several other operators on that frequency, though, unlike what you usually find. We met up again back on the Wisconsin .195 for a bit, but I was eager to explore the airwaves and find what else I could reach.  

  I thought that I hit the 145.310- (110.9 PL) in Duluth, but it was just the St. Paul repeater on that same frequency that uses no PL tone. North wasn't very good to me, and I couldn't even reach the LSAC Giese 146.865- repeater. Maybe it's off-air, anyway. So I turned the beam to the south and quickly picked up several distant machines: 147.105- (Owatonna), 147.240+ (Mankato), 146.910- (Willmar), and the 146.940- in Waseca. 

  I was feeling pretty cocky at this point -- or pretty cocky for a guy with 50W and a cheap Yagi, that is -- and I decided to try for the repeater in Fairmont. Alas, it was not to be. Right about then, I heard a crash and saw that the tripod on my balcony had toppled over the edge, dropping three stories to the ground. I had failed to put the weight on the bottom cross-bars after I rotated it to the south, and the wind must have come up. 

  Obviously, I was horrified. This could very well be just the pretext the HOA would need to ban the further use of the tripod. "Someone could have been killed!", they would say. Highly doubtful, of course. Rushing outside, apparently no one had seen the potential disaster. I was amazed to find that the tripod was completely undamaged. The Yagi, however, was destroyed. The tape measure elements were permanently bent, the PVC pipe of the boom was cracked, and the crimp-on connector had been pulled off. 

  That pretty much put an end to the day's explorations, and conditions were declining already. 

  I briefly pondered getting a better beam to replace the cheap tape-measure Yagi. The problem would be storing it when it wasn't in use. The tape-measure Yagi was designed for portable use, and it broke down into sections with the elements folding in to the PVC pipe. For all of its faults, I ordered another from eBay. 

  So, it'll be a few weeks before I can get back on two-metre SSB. Even though I've had very little luck making contacts, it's an interesting change from FM and it's been a good chance to use CW outside of HF.

Loose Notes 6/14/15

Another quick run-down of the previous week's radio developments:

• I guess that there was some kind of MS 150-type event over the weekend, as there was a lot of APRS traffic indicating that. The Hinckley K0YTH-10 digipeater got a work-out, and a lot of traffic bounced off from that machine to the N9XH-4 (Balsam Lake, WI) digipeater, to the northern metro digipeaters (e.g. N0HOY-14 and K0LAV-8). The network of RX-only I-gates did a great job handling the extra load. 

• Another new digipeater has sprung up in Brooklyn Park. KC0KEP is located near the Crystal Airport, and the new digipeater has handled a lot of packets for the recent weekend event from Forest Lake and even further north. I'd rather see such a nice receiving setup acting as a gateway instead of a digipeater, but we need something in the NW metro. Hopefully, this new addition will stick around. 

• My new 15M dipole (with balun) has arrived in time for Field Day. Barry from Hy Power Antennas was as good as his word, and I'm ready to wade back into HF waters -- if only for a day. I'll be setting up in St. Louis Park with KE0NA (Dave) for QRP operation on 15M and 10M using voice and CW. Look for us on APRS to find out the band/mode we're working at the moment. I expect to have my 5W HT running into my three-element Yagi, and that should reach the local packet infrastructure just fine. 

• On Saturday (6/13), I was surprised to hear KE0NA on the local C4FM 442.925+ (114.8 PL) repeater. I was even more surprised when he told me that he was operating mobile on the 223.900- (100.0 PL) repeater. Obviously, the WIRES-X link to the 1.25M repeater has been restored by N0BVE (Don) over the course of the past week. The audio was strongly "digitised", and I scarcely recognised Dave's voice, but he was completely readable. The EchoLink node for the 224.660- (100.0 PL) has been down for a few weeks now, so the .925 is the best way to operate on 1.25M if you don't have a radio for the band. 

• Speaking of the 442.925, I had a chat there this week with KA8JRJ (Fred). He was operating on WIRES-X from Michigan through a hub in Texas. Per Fred, the WIRES-X room in Beaumont, TX connects several repeaters across the country and even into England. The local 442.925 machine is one of those repeaters linked to the Texas hub, so it's a good place to hang out for some out-of-state conversation. 

• I had my first 2M SSB contact this week! I was immensely surprised to hear KA0RYT (Ron) come back to me on CW, and he then suggested moving to SSB. I first heard someone on CW while casually listening on 144.200 with a vertical whip, so I put up my VHF Yagi hastily. It was set horizontally, and pointed east. This greatly improved the signal, and I was able to tune in precisely and get the callsign. The tone of the CW signal was a bit raspy, but I could copy it. After making contact, I learned that he was in Milaca (to the north-west), and I turned my beam towards Ron for even more improvement in the signal. At a distance of 50 miles, this was my furthest two-metre simplex contact yet.

• I put some LMR-240 coax on my Sirio GP-430 UHF ground-plane antenna this week, replacing the RG-8X that I've been using. This is the antenna that looks like a beer can with three radials sticking out. I've had the mount for about two months now, and I've been using it on UHF FM to get into the local amateur repeaters, as well as the local GMRS repeaters. It's very wide-band and shows flat SWR on all of the 440-MHz frequencies and even up into the 467 MHz GMRS repeater input frequencies. I've been relying on it heavily to reach the 442.425+ DMR repeater, as well. The radials provide a rock-solid signal that my other whips don't give me, and I no longer have to swap antennae to work GMRS. The upgrade to LMR 240 coaxial cable has given me (much) less noise from neighbours' electronics, and boosted reception by about one S-unit. 

• One of the first repeaters that I tried with the new coax was the 444.050+ (114.8 PL) in St. Paul. It's always been a challenging UHF repeater for me to reach. I got in well at 10W, and caught up with N0GOI (Terry). He's taking a well-deserved break from developing his various repeaters, but he still has plans to link the VHF 145.170- (100.0 PL) to the UHF 444.050 machine. Ultimately, he wants to create a cross-band linked network that would incorporate the NE Minneapolis 444.575+, the Hugo 443.050+, and the Foreston VHF and UHF repeaters into the previously-mentioned cross-band pair. It's an ambitious vision, but one that would create activity on currently-unused repeaters and expand coverage dramatically.      

Exploring FM simplex

  I haven't done much with amateur FM simplex on any band. It's something that has always seemed to be the domain of those with big antennae and powerful rigs, at least to me. It's certainly not an aspect of the hobby suited for HT operation. Still, the experiences that I have had on simplex have been very positive and interesting, and also completely counter to my pre-conceived notions. I've run into several new(er) hams on repeaters that also see FM simplex as something that's "not for them", so I thought I could share a few of my experiences and get a few people to experiment with FM simplex. 

  Long years on GMRS using a hand-made Yagi didn't really help to prepare me for amateur FM simplex. Once the big GMRS repeater in Golden Valley shut down, local operators were forced to switch to simplex, and the results were disastrous. UHF FM simplex is difficult without a directional antenna, and most of the operators didn't have one. I saw simplex as something that was useful for maybe five miles -- in other words, not that useful. 

  So, when I got my amateur licence, I was thrilled with the world of UHF repeaters that suddenly opened up. Of course, most of them were dead, but just the potential of reaching people outside of UHF simplex range was exciting to me. I think that most long-time hams have completely forgotten what that thrill is like, and they've become jaded by the ease with which their 75W rigs with rotating beams can communicate with people far away. Still, though I had access to repeaters, I did try UHF FM simplex several times. It was more out of a sense of exploration than any actual expectation of having a conversation. I found no one on the 446.000 frequency, and I had no way to determine how far I could reach. 

  It wasn't until I got in to 1.25M that I found out that I had any potential for FM simplex. KD0UDM (Neal) and I were in a QSO on a local 220 MHz repeater, when Neal suggested simplex. It was only about eight miles between us, and I had 25W running into a three-element Yagi, so it seemed possible. I didn't expect much more than a barely readable signal mixed in with the background noise, but it sounded like a fun experiment. To my complete surprise, we were full quieting and even clearer than we had been on the Arden Hills repeater. 

  That experience got me thinking. Though I didn't have a 2M beam, it might be possible that VHF FM simplex could be an option. At that point, I had an FT-897D and 50W, though my antenna was only a mobile whip. I threw out my sign several times on 146.520 without luck, and I began to think that 2M FM simplex wasn't a viable option for me. It wasn't until I ran into K0MPX (the weather station in Chanhassen) on 146.52 months later that I became convinced that VHF simplex was something that might actually work. 

  What I found over the next few months was that most of the activity didn't really take place on 146.520 -- which is the national calling frequency. I ran into N0KFB (Dan) on 146.580, and others on 146.500 (which isn't an allocated channel), and I got decent signal reports. And, a few weeks ago, I ran in to KC0WHJ (Dennis) and KC0FHA (Al) on 147.555. Dennis was only about 8 miles from me, but Al was about 30 miles away -- which was the furthest that I had ever reached. My success was mostly due to their superior rigs, but both of them were very encouraging about exploring VHF FM simplex further. Still, it's clear that you need to know where to look in order to make contacts. It's not the same as operating on repeaters in that regard. 

  UHF simplex still seemed out of reach, however. KA0KMJ (John) and I had successfully talked on 446.000 a few times, but he's only about five miles from me. KE0CRW (Greg) and I have also played with UHF simplex at QRP levels, but he's practically next door to me. Last weekend, though, KE0NA (Dave) and I tried a QSO on 446.000 -- a distance of nine miles. That seemed a bit far for simplex to work in an urban environment, and I was sceptical. Still, we both had 20W and beam antennae. It seemed like a possibility. What I found was something unexpected. 

  With only an S2 signal between us (at best), we were both completely readable. UHF doesn't have nearly the same level of noise as the lower frequencies, and the natural characteristics of FM worked in our favour. I don't think that doubling our power would have improved things much, and it seems as if we could have used less power and been successful. More than anything, UHF requires a clear, line-of-sight path. While there was only about 20 feet difference in our elevation, there were a lot of obstacles between Plymouth and NE Minneapolis over those nine miles. If both of us had 50- foot towers at our disposal, I'd have expected much better results in terms of signal strength. But, as it was, it worked remarkably well.

  What I took away from this is that UHF simplex is possible, and even enjoyable, in the right conditions. Even an HT, connected to a Yagi and given an unobstructed path (e.g. a hill overlooking your target location) could do pretty well on simplex. You might even run across someone that has 446.000 programmed in to their radio, and they might come across you while scanning. Realistically, though, I can't see amateur UHF FM simplex ever approaching the relative popularity of VHF FM simplex. If you had a good location or tower, you'd probably have better luck with GMRS in terms of finding someone to have a conversation with. 

  I've read on a British amateur blog about UHF SSB, with common ranges of 50 - 60 miles. That sounds intriguing, but it's another one of those things that nobody really does here, so you would have to set something up in advance. I've experimented with it before using vertical antennae (with AE0CX and N0YNT), but the results weren't very compelling. 

  I consider myself fortunate to have come across local operators that haven't lost their interest in experimenting nor their fascination with radio itself. When something becomes so easy, such as operating QRO with the best antennae, a lot of the excitement and mystery just gets drained out of the experience. FM simplex, to me, is interesting because it's a challenge. To others, it's just a way to isolate yourself from "the repeater crowd" and associate with a more 'refined' type of amateur. It's no more of a challenge than reaching a repeater for most of those on two-metre simplex. While I've no use for that kind of mentality, it's still something that remains interesting to explore, and I'd encourage new hams that haven't played with it to push at the boundaries and have some fun. That way, you won't get jaded and too 'experienced' to explore the various niches of the hobby.

Exploring two-metre FM

In the past month, I've spent more time on two-metre FM than I have in the preceding six months. Normally, I'm on UHF and 1.25M, as my FT-897D was in repairs for a few months and I could only get on VHF with an HT. So I kind of got out of the habit of checking two-metre repeaters, or even swapping in a 2M antenna on my mount. When I put the Leixen VV-898 in my study with an indoor mag-mounted whip, I spent a little time finding out which repeaters I could reach, but not really engaging in conversations on VHF. But I finally programmed all of the local two-metre repeaters into my FT-897D and took the risk of putting up my more-conspicuous monoband VHF whip outside here at the condo, and it's a different world. 

It's pretty easy to reach the 146.790- (100.0 PL) machine in Faribault, I've found. Along with that, the 147.360+ (136.5 PL) in Hampton (near Northfield) is quite accessible, Becker's 147.345+ (85.4 PL) is nice and clear, and the 145.210- (114.8 PL) in Crown (between Zimmerman and Isanti) is almost like a local machine as far as coverage. The west is now open to me with the (previously mentioned) 145.230- (114.8 PL) Maple Lake HandiHam repeater (which is not linked to the network). 

Certainly, we have some excellent local VHF repeaters, and the activity is generally higher on them than what you find in the more far-flung reaches of 2M FM. And you can reach across Wisconsin on the UHF WINET repeater in Arden Hills. And, generally, UHF is where actual, meaningful conversations are common. But I can see where 2M gets its reputation for distance. 

This is what I found out tonight by investing less than an hour on two-metre FM: 

• The 145.290- (114.8) repeater in New Brighton is back on the air, after being down most of the week. The owner, N0FKM (Dan), has told me before that the repeater doesn't tolerate cold weather well. The City won't let him add a space heater to the shack, and there isn't enough activity to keep the machine warm by simply transmitting. So when it gets cold, maybe think about a QSO on the .290 to warm that machine a bit. 

• The Hudson 145.130- (110.9 PL) machine has developed a nasty hum in the audio, though it's reaching Plymouth better than it did last winter. 

• I had a brief chat with a guy at the National Weather Service station, K0MPX (John), on 146.520 FM simplex. I've heard the station on the 444.775+ (114.8 PL) machine in Robbinsdale before during bad weather, but I had no idea that they used VHF, much less simplex. S9 here in eastern Plymouth from Chanhassen, so they must have a decent rig and antenna for two metres. It might be an interesting way to check your simplex range, but be sure to have your local weather info at hand. 

• It seems crazy, but I "ker-chunked" the two-metre 146.865- (146.2 PL) in Giese (northwest of Sandstone) for an S3 signal. Gotta hand it to LSAC, even though their .325 UHF repeater has been down for about a year. 

• I could kind of reach the 145.250- (100.9 PL) machine in Baldwin (WI) at S6, but there was a huge amount of noise. I think that somebody came back to my sign, but I couldn't read them in all of the noise. It seems a lot easier to reach the east metro and beyond into Wisconsin on UHF, though I understand that the 146.850- does pretty well with a remote receive site in Roberts, WI. Still, it's trivially easy to reach the UHF 443.025+ machine in River Falls directly, and the 442.075+ (110.9 PL) repeater in Arden Hills can be readably reached with an indoor 4W HT from here in Plymouth -- and that links you into all of the UHF machines across Wisconsin. 

So that sums up an interesting evening exploring the more distant reaches of two-metre FM. I always prefer close-at-hand quality conversation to distant non-conversation, but I have to admit that there's potential there.

FM procedures: the roundtable, the net, QSY, and simplex

Previous posts in this series: 

• Preface 
• Throwing out your sign
• Specific calls and clearing
• Closing and interruptions 

 The exchanges in this series are completely fictional. The callsigns were chosen at random from my log book.

The terms "roundtable" and "net" are frequently confused. Both involve multiple operators. 

A net is more formal, is usually regularly scheduled, and each operator generally gets one turn. It's not a framework geared for conversation, but rather an exchange of information. There is a "check-in" on a net, where operators are allowed to join the net in an organised manner. There is also an NCO (Net Control Operator) that has actual control over the frequency and decides who gets to speak at which time. Nets are highly-organised and contrived affairs, with a rigid structure, and they are widely popular. I'm not going to get into net procedures, as each net has their own variations of procedure. Sometimes, procedures are posted on the net host's website. Generally, though, a good NCO will spell things out during the course of the net so that virtually anyone can participate without disruption. 

Stumbling into a net and disrupting the highly-organised structure is a good way to be labelled as an idiot in your local community, however well-meaning you may be. The best advice that I can offer is to listen to an entire net first, and then try joining in on the next scheduled occurrence. Take notes on procedure. Some NCO's are very welcoming and understanding, while others operate with an iron fist and a sour attitude. Still, if you do your homework, you should be able to navigate even the strictest net and establish yourself as a "non-idiot". 

A roundtable is multiple operators taking multiple turns. It's much like a two-person QSO. Roundtables are usually more spontaneous and loosely organised, and frequently evolve from an interrupted conversation between two operators. N0YNT (Matt) has written an excellent post about different organisational styles with multiple operators on a repeater. It's highly insightful. On roundtables, Matt wrote this: 

Everyone gets a turn, regardless if they have anything meaningful to say or not. (Most often, people have nothing meaningful to stay when they get a turn and spend round after round turning the chatting over  to the next dude "in line" for time on the air.)

And that's pretty accurate. Everyone gets a turn, and the "talking stick" gets passed to the next person in the order. The "order" is established by how people joined the conversation. If you jumped in after operator A, then you will always be after operator A in "the order", for the duration of the roundtable. The problem is that conversations don't usually work that way in the real world. As more people join in, and the conversation takes multiple paths, "the order" becomes an obstacle. 

Still, as far as procedure goes, this is how a roundtable works. Each operator takes a turn, and passes control to the next operator in the order. Every operator involved in the roundtable has control when their turn comes up, which means that every operator is: 

• supposed to clear when they leave
• required to state their callsign when joining the roundtable
• required to identify when they leave the roundtable
• required to identify every ten minutes during the duration of the roundtable

 Roundtables are, of course, more informal than nets. A roundtable isn't usually scheduled; it just happens. Often, roundtables are recurring on a particular repeater -- during drive time, for example. They may be called "nets", but they are actually roundtables. There is no NCO, and the participants each get a turn in an established order. There usually isn't a defined start time to these roundtables. It starts when operators start turning up, and it it ends when everyone has dropped out. There's a core group, and it can be difficult to break in if you aren't in that group. This is a specialised example, though. Most roundtables simply evolve from conversations spontaneously.

You can, of course, turn a roundtable into one of the other organisational styles that Matt describes, if you wish. Simply cease enforcing "the order". Still, in any alternate arrangement, the requirements that I stated for a roundtable (clearing and identifying) still apply.

Let's look at an example of a roundtable evolving: 

"N0YNT monitoring" 
"N0YNT from KD0TLS mobile"
"Hi, Todd. You're out driving in this snowstorm?" 
"Yeah, it's not a lot of fun. County Road 9 hasn't even been plowed" 
"UIH" 
"Hey, it's Chuck. N0YNT. Go ahead, UIH. 
"KD0UIH. How's the Crosstown, Todd?" 
KD0TLS: "Hi, Chuck. Lucky for me, I didn't have to take the Crosstown, so I can't tell tell ya. Over to you, Matt"
N0YNT: "I heard on the radio that here's been four accidents already on the Crosstown. Over to UIH" 
KD0UIH "I have to take it when I leave here in 15 minutes. It sounds bad. I guess Todd has it"
KD0TLS: "You can take 55 and go through town, right? It's slow, but 62 will be slower than slow. Matt has it, I think" 
N0YNT: "I'm just staying at home. Hope that I don't have to go out. Over to you, Chuck" 

Here we see a roundtable evolving. Each operator passes control ("it") to the next person in line. KD0UIH joined in after N0YNT, so "the order" goes: N0YNT - KD0UIH - KD0TLS. 

You may want to scribble down "the order", especially if you have four or more people involved.

The "order" ensures that nobody gets left out, even if they have nothing to contribute to the conversational turn of the moment. Those experienced at roundtable discussions will try to introduce secondary topics of conversation to involve the person who is left out of the primary conversation -- in this case, the condition of the roads during a blizzard. You can always "pass" on your turn and "hand it over" to the next person in the order, if you have nothing to add. Just say that you have nothing to add, and cede control to the next person in line. If you really don't want to be a part of the discussion any more, then just "bow out" by stating your callsign and clearing.

It's important to note that there is nothing sacred about "the order", and it can be modified over the course of the roundtable. Without some clear idea of which operator has "it", however, two operators involved can believe that they both have "it" and end up talking over each other (doubling). That's a waste of time and irritating to those listening. 

While the roundtable has its limitations, judicious use of the "pass" option and an effort to move the conversation in a direction that suits all parties involved can make it move smoothly and enjoyably. 

Since activity draws activity, you will probably find that a good conversation will draw an audience. Remember to leave space between each transmission for "breaking stations", even if you don't want to allow anyone else in. 

Also remember to keep track of the time, so that you can identify at ten minute intervals. I keep a simple kitchen timer by my radio, or use the timer function on my smart-phone. Otherwise, the operators involved will tend to "over-ID" just to be safe. Those ten minute intervals are also good opportunities to invite others listening to join in, though you can do that at any point. Some repeaters will ID at ten minute intervals, but you can't rely on that. Identification at the ten minute intervals isn't anything elaborate or specialised. Just state your callsign at minimum, or add the words  "for ID" after the sign to remind others that it's been ten minutes. If you're operating at home and everyone else involved in the roundtable is mobile, then it's kind of your responsibility to keep track of the time. There's no need to obsess over the matter. If the ID comes at eleven or twelve minutes, nobody is going to swoop in and get uptight. If they do, they've got a serious problem. If the operators involved start to "over-ID", just mention that you have a timer or that you're keeping track of the time. Ten minutes can go by pretty quickly when there's four or five people involved in a good discussion.

Other precautions to bear in mind are to always let the repeater drop after a transmission, and avoid talking over the repeater ID. Repeater IDs are usually the callsign of the repeater in Morse code, though voice IDs are gaining in popularity as controllers become more advanced. The repeater has to identify itself in the same way that you are required to identify yourself, so don't "step on" the repeater ID. You can (and should) use the names of operators once the initial identification by callsign has been made. 

Remember that these procedures are established to make the use of shared resources operate smoothly. They aren't an end in themselves. The sort of person that gets really uptight about procedures is generally the sort of person that has marginal conversational skills. FCC requirements aside, as long as your procedures don't confuse others as to who is in control at any given moment or who you really are, then a roundtable can employ more 'fluid' procedures to suit the individuals involved.  

You will find that different repeaters have different "personalities". Some are very strict and deadly serious, and others are more open to conversations and "banter". Others are simply dead. Rather than starting up a conversation on a "serious" repeater, you are best off to establish contact and move to a dead or more 'friendly' repeater for your light-hearted conversation. Simply suggest to the other person that you both move to a specified repeater. If they agree, then announce that you are moving and clear. 
Here's an example: 

"KD0YRD mobile and listening" 
"KD0YRD, this KE0NA. Hey, can you move to the 444.375 repeater? I want to hear how your classes are going."
"Sure. This is KD0YRD clear and moving to the .375"
"KE0NA clear and QSY" 

"QSY" means "moving to another frequency" in "hamspeak". Notice that both operators identify themselves with their callsigns at the start and at the end of this short contact, and that both of them clear the repeater that they are on. Once at the new repeater, they can throw out their signs or make a specific call to establish a new contact. You need to start all over again at the new repeater. You also need to make sure that the new repeater is clear by listening for a moment or two. If the new repeater is in use, then you can ask to interrupt and then suggest another repeater by way of a specific call. Making a specific call while a repeater is in use is considered to be "bad form", so the best advice is make sure that the repeater is clear before you suggest moving there. 

Here's an example: 

"KD0YRD mobile and listening" 
"KD0YRD, this is KE0NA. Can you stand by for a minute, please" 
"Sure. KD0YRD standing by" 
"KE0NA clear" 
< checks the 444.375 for activity > 
"KD0YRD from KE0NA" 
"KD0YRD. Go ahead, KE0NA" 
"KE0NA. Hey, can you move to the 444.375 repeater? I want to hear how your classes are going."
"Sure. This is KD0YRD clear and moving to the .375"
"KE0NA clear and QSY"

Okay, let's look at what happened here. KD0YRD threw out their sign. KE0NA established contact with a specific call. KD0YRD went on standby, which surrenders control of the repeater. KE0NA cleared, because the specific call gave him control. And, since nobody had control when KE0NA returned, they started all over again with a specific call. Then, they both announced that they were moving and cleared, since the specific call established a contact -- and control. Once at the 444.375 repeater, they must begin all over again. Got it? 

There's no need to specify the frequency that you are moving to when you clear. It just ensures that there's no confusion in the move. Technically, you don't even have to say that you're changing frequency -- just do it after you clear. Announcing your QSY is a courtesy, but hardly a necessary one. Others may wish to follow you. Others may have wished to make a specific call to KE0NA or KD0YRD when they cleared, but they now know that neither of them is on the frequency at that point in time. Also, someone else may show up shortly afterwards and make a specific call for KE0NA, for example. Others can then inform the operator that KE0NA moved to another frequency and is not around. The important thing is that both operators cleared before changing frequency, and in so doing informed everyone else on the repeater that it was available to use. 

QSY can also be used if one person in the contact isn't getting in to the repeater very well. Rather than trying to have a conversation with someone buried in noise, you can suggest a repeater closer to them (or with better coverage). That's not only polite; it's also sensible. This is where your familiarity with the local repeater "scene" is valuable. Perhaps you've spoken with the other person on another repeater before with good results, and you know that it will be an acceptable substitute in advance. Worst case, you can simply ask the other operator which repeater works best for them, and offer to move there. Hopefully, that repeater also works well for you, too. 

Even if you are accessing a repeater with EchoLink, you still have to follow all of the procedures that apply to someone using a radio. Even though the link announces your callsign upon connection, you still are required to identify yourself when throwing out your sign or making a specific call. You still have to listen and determine if the repeater is in use or not before transmitting. You still have to clear when giving up control over the frequency (if you do establish control at some point). But you don't have to announce that you're disconnecting if you don't have control. You don't have any special status as an EchoLink operator, though most nets will make special accommodations to allow EchoLink users to check in -- provided, of course, that the net is on a repeater that has EchoLink implemented. The link announcement doesn't serve as a request to "break", nor does it replace throwing out your sign. 

Procedures on FM simplex aren't really different from those used on repeaters. There's no waiting for the repeater to drop, nor is there a repeater ID. The simplex channel is a shared resource in the same way that a repeater frequency is, and procedures ensure that everyone knows who has control of the frequency and when they can make their calls. You identify, clear, and handle interruptions on simplex exactly as you would on a repeater. You can have roundtables (and even nets) on FM simplex. PL tones generally aren't used (nor encouraged) on FM simplex, unlike on repeaters.

On FM simplex, there is a particular channel established by convention as a "calling frequency". On two metres, 146.520 serves this purpose. This is where operators listen for each other and meet up, and it's not for extended conversations. You can use a specific call or throw out your sign to establish a contact on the calling frequency, but you should then QSY to one of the many other channels for your conversation. Short conversations (two or three "go-rounds") can be had on the calling frequency, but don't push your luck. Even if people aren't waiting to use the frequency to make a call, they are still listening to the frequency for people calling them. It's best to just change frequency right away, and have a favourite one ready in your mind to suggest when you make your call. Once you move to another channel, you will have to start all over again with your procedures, but you can talk as long as you like without irritating anyone.

This has been a long post, but I wanted to get this series wrapped up. Maybe one of our guest writers will go into depth on some matters touched upon here, or explore specialised aspects of some procedure. Still, this series covers the fundamentals that will allow new hams to operate alongside experienced hams without a lot of friction.

May AITP: do a "sked"

I've been thinking more about the upcoming (5/10) Aerials In The Park (AITP) event at Long Lake Regional Park in New Brighton. While I'm kind of limited as to what I can (and want to) do on HF, there are some interesting things that I can do with 2M, 1.25M, and 70cm as a portable station, and these things could increase public involvement with the event -- even if they aren't there.

What I'm contemplating is a "sked", with particular time slots dedicated to certain bands and/or modes, so that you are could reasonably expect to have a contact if you decide that you want to play along at home.

Maybe you can't make it in person to the event on May 10. You could still be a part of it by experimenting with some different things and seeing how well they work. For example, I'll have my 5W tri-band TH-F6A with a 1.25M Yagi. It's great for FM simplex. Maybe you want to try out your HT for 222 MHz. It would be nice if you knew that someone was going to be on 223.500 from a particular location at a certain time, wouldn't it? You could try it out, on the air, with some guy at a park in New Brighton on the afternoon of May 10.

I'll have my FT-897D on the internal batteries, so I can do AM/FM/CW/SSB on HF to 70cm -- in theory. I don't have any HF antennae (beyond a 10M "hamstick" dipole), and I'm limited to around 15W power. But I do have antennae for 2M, 1.25M (222 MHz), and 70cm (440 MHz), in terms of beams and omnidirectional types. I could do weird stuff like UHF CW or two-metre AM, or just more conventional VHF SSB and FM simplex. While the FT-897D doesn't include 220 MHz, I do have the (aforementioned) tri-band HT for FM on that band, and it can RX in SSB/CW on 1.25M. 

I intend to be there for about three hours, and I'll have a VHF/UHF Yagi, a UHF 1/4-wave ground-plane, a VHF 1/4-wave ground-plane, a tri-band "gain" whip, and a 1.25M Yagi. That's a lot of antennae already, so I'm going to pass on the ten-metre stuff. Maybe I'll bring a six-metre roll-up J-pole, because it's easy to pack. 

I'm also going to be doing some more serious propagation reports on FM repeaters. I'll be monitoring my transmissions to determine if I actually get in to the repeater, not just "ker-chunk" it. The results will be published here, and also on RepeaterBook. At last month's event, I was working more on a "proof of concept" angle for the entire tripod/mount feasibility. I'm also going to add a ground rod to drain static charges off the antenna. 

If you have any suggestions for modes/bands that you'd like to try out, just leave a comment or email me. Also, feel free to stop by and play with the radio, if you do decide to come to the park. I'll be by the gate, so it'll be easy to find me. And I'll be monitoring 444.425 during the event if you'd like to co-ordinate something over the air. 

Even if you don't make it to Aerials In The Park on 5/10, think about setting up something portable that afternoon. Maybe a tripod in your yard with a whip or a two-metre roll-up J-pole hanging from a tree limb. Maybe some hand-held log periodic for UHF satellite links. We're not talking Field Day here, but it might be a chance to set all of that stuff up once this Spring and make sure that it's all working like you think it is. And, as long as it's set up, why not have a QSO with someone else doing "portable ops": me. Actually, the event is planned as monthly, so you'll have other chances in the future, but I'm one of the few people there doing any FM at all, and the only one that did anything above ten metres last month.

 KD0KJI (Al) was one of the founders of last years' event, and he explained to me that AITP was intended as kind of a ham radio outreach effort. Ordinary, non-hams would see the aerials and inquire about amateur radio, and see it actually working right there in front of them. Although...last month's event didn't feature a lot of wire dipoles. Instead, there were a lot of "portable ops" antennae, but every month is different, right?

Aerials in the Park 5/10 pre-event thoughts

Last month was the first Aerials in the Park event this year. Though I arrived late and set up by the gate of Long Lake Regional Park, Brandon (callsign forgotten) turned up and lent a hand as I set up. Soon afterwards, N0YNT (Matt) and N0TYE (Paul) joined me. It was a bit blustery and chilly by 4 PM, so we broke it up.

I used a 13-foot tripod and attached an NMO ground-plane kit to the mast with hose clamps. Then, I could use any NMO-mount mobile antenna for FM work. My Yaesu FT-897 had the internal NiMH battery packs (FNB-78), so I was limited to 20W (10W on UHF). That pretty much left me with FM repeaters to work with, as I had no directional antenna for simplex. It interesting how many distant repeaters I could hit from that location.

For the next event (5/10), I've been contemplating using a DMount and two ten-metre ham-sticks for some SSB/CW, as there wouldn't be any concerns of interfering with neighbours' electronics at the park. 20W on CW isn't bad, although nobody will QSO with me at 6 or 7 wpm. Essentially, I'd just be doing it for "show". And, as long I'd just be screwing around, why couldn't I do two-metre CW? I could string up a 1/4-wave dipole for two metres on that tripod, and draw a big crowd of arrogant 'superiors' telling me that I'm doing it wrong.

It also occurs to me that I could take advantage of the event for a little FM experimentation. If I'm at a known location, at a known time, other hams could use their superior power or antennae to reach me on FM simplex. With my limited power and my Technician licence, there's not much that I can do there that a dozen other people will be doing a dozen times better. I have a 1.25M Yagi, but I don't have the portable power to run my TYT TH-9000. Maybe I could use my 5W HT and try some 1.25M FM simplex. There are enough people in the metro with 1.25M FM HTs or mobiles that it might be interesting for everyone involved to put those to the test in a scheduled situation.

Spring is the time for hams to repair or upgrade their antennae, so why not have some crazy dude like me out in a park giving signal reports? It beats being ignored by CW snobs on HF as I pound away on a straight key for an hour or two.

As long as CW operators ignore the letters "QRS", I will continue to ignore their dead language.

Maybe there's some kind of "joint effort" possible with another ham in terms of gear to make this a better situation. Either way, I should be looking at some kind of schedule so that people will know which band I'll be on at which time.

Potential HT range calculations

I came across an interesting article on a Dutch ham radio blog about the range you can expect with a VHF HT using simplex as a "walkie-talkie". As it turns out, the range of a 5W two-metre HT isn't limited by power; it's limited by the curvature of the Earth. Now, while I had known that already, I was surprised to find how small that distance really is.

Using math, and assuming ideal conditions, the blog post proved that the maximum range was 5.7 km -- or about 3.5 miles. And that would be a best-case scenario: no trees, flat terrain, no buildings. Realistically, the author estimates that "walkie-talkie" range is about one mile. Doubling the RF output power would only extend that ideal range to 4.9 miles, while reality would cut that down to about 1.5 miles.

Obviously, this is operating at ground level, and not with a roof-top antenna on your home. It also doesn't account for using repeaters. Neither does it take into consideration tropospheric propagation, but you'd be foolish to rely on that regularly. Still, it puts the manufacturers' claims of potential range in an unflattering perspective.

It also makes me very happy that we have repeaters.

FM has inherent range limitations of its own; it's not a "weak-signal" mode. A relatively strong signal is required for a demodulator to separate a signal from background noise, and there are always phase cancellations produced by the signal bouncing off various man-made structures that further conspire to reduce that signal strength. Two-metre FM is not used because it offers tremendous range. It's used because it's convenient. A smaller antenna can be used compared to HF (which bounces off the upper atmosphere for much greater range), the signal is either relatively clear or completely unreadable (much like digital voice modes), and a squelch can be used so that you don't have constant noise between transmissions.

Every time that you have a successful QSO (conversation) on FM, you are overcoming formidable obstacles placed there by physics and the very planet that you walk upon.

The 1.25M band plan, and more scary simplex links

In my previous post, I touched briefly on the feasibility of using 1.25M (220 MHz) for simplex links to repeaters through Echolink. After writing that post, I took a closer look at the MN band plan for 220 MHz.

What we see is a band primarily designed for FM repeater operation, but without any provision for auxiliary links. "Control links" are shoe-horned in to the "guard band" space between repeater frequency pairs, but this is explicitly limited to control uses, and not audio auxiliary links.

"3)  Control Link Frequencies. It is suggested that control links  (control  but  not  audio type control links) be conducted on  the  10  Khz channels between the repeater output frequencies."

 What the Minnesota Repeater Council (MRC) has essentially done is to eliminate the possibility of RF repeater linking using the 220 MHz band. In a recent on-air conversation with WD9IGX (Tim), he expressed the opinion that the RF links needed for cross-band use be conducted on 220 MHz. But this is simply not allowed by the band plan. I agreed with him, to a point, because I was unaware of the conditions within the band plan.

The "vision" for 1.25M in Minnesota, therefore, is one of "stand-alone" repeaters. The only way to get around this and create any kind of linked network on the band is to use the internet -- which is something that always makes the MRC "nervous" for some vague reason. Of course, UHF (440 MHz) can be used for this purpose. In fact, it looks as if that's the only way the MRC allows RF links between repeaters. There's about 2 MHz set aside on 440 MHz for that purpose -- for all bands, all repeaters, and all remote receive sites across the State. And there's a 50-mile restriction for each of these frequency pair assignments.

A total of 57 frequency pairs are designated for FM repeaters on the 1.25M band. This is a lot, but nothing compared to the number for two metres (70 pairs) or 70 cm (96 pairs). Still, you have to work with the space that you have. UHF has about 30 MHz to work with, and two metres has around 7 MHz. 1.25M has only about 3 MHz of space to allocate between various uses. You should also realise that those 57 pairs have to distributed around the entire State, with consideration for assignments in nearby States.

So, it's a relatively small band to begin with. But it's largely unused, so it's understandable that people (like me, for example) have a notion that things that don't fit on two metres should be done on 1.25M.

There isn't a lot of "wasted space" on the 220 MHz band to carve out quick fixes with. Only 250 kHz is devoted to "weak signal" modes -- which is smart, given the lack of equipment and compatibility issues with frequency assignments in other countries. Only seven channels are designated for digital operation, and two of those are shared with FM simplex. The rest is FM repeater pairs and FM simplex.

For two-metre FM simplex, there are 72 "wide" simplex channels and 25 "narrow" simplex channels.
1.25M has only 13 (20 kHz spacing), and two of those are shared with packet simplex.

With that in mind, which band seems like the practical choice for simplex links to repeaters?

Two metre simplex

Sure, there's barely any activity on 220 MHz simplex, and zero simplex packet activity on the band. But how much FM simplex activity is there on two metres? There is some, definitely. But it's not as if the calling frequency (146.52) is crowded. This idea of meeting up on 146.52 and moving to another channel to keep the calling frequency "clear" is a quaint relic. Even so, how many channels are needed for this purpose? Are we really going to pretend that there are usually even five simultaneous FM simplex conversations going on? And keep the range in mind, too. How far is your typical 50W mobile going to reach in the metro environment? I'd guess twenty miles. Now we're down to insisting that there are more than five simultaneous FM simplex conversations taking place within a 20 mile radius. Sure. Sure there are, buddy.

But let's double that. Now we're claiming, with a straight face, that there are ten simultaneous FM simplex conversations going on in the metro commonly. I must have a really bad receiver, because I don't hear that happening.

That makes a total of eleven FM simplex channels needed: one calling frequency and ten simplex channels.

How is that a strong case for keeping an additional 14 channels free?

220 MHz simplex

The thirteen FM simplex channels on the 1.25M are basically unused. I've heard two guys having regular conversations on 223.700, and nobody uses the calling frequency (223.500) at all. They have a "sked", and they meet there for a while at night.

Without a doubt, five FM simplex channels on the band could be designated for simplex links to repeaters and nobody would be inconvenienced at all. Using PL tones on the input of the links would prevent normal simplex activity from being transmitted to the repeater, since normal simplex traffic isn't using CTCSS. It would be highly unusual if there were more than five hams within FM simplex range of each other all wanting to set up simplex links to various repeaters.

This would leave seven channels, plus the calling channel, for all of that FM simplex activity on the 1.25 band that doesn't exist.

Summary

Simplex linking to repeaters using the internet could be done on 220 MHz. It would help promote the use of the band, and it could increase the amount of 1.25M-capable equipment out there. It's also a very cheap and simple method of increasing the coverage of FM repeaters. It could be used to supplement coverage in areas with low elevation, or it could be used to provide access to repeaters in areas well outside of the local area.

But these same things could be said, and even more so, for two-metre FM simplex links using the internet.
It's obvious that there are far more hams in the community with two metre radios than there are with 220 MHz gear. It's also hard to argue that five of the 25 available FM simplex channels on two metres could not be designated for this purpose, and possibly twice that many, while inconveniencing no one.

It would require nothing more than a transceiver, a computer, and an internet connection to accomplish -- whereas a UHF RF link would require a tower, a dedicated UHF repeater, a duplexer and a controller. And also a duplicate arrangement on the repeater end.

The key to the successful implementation of an effort like this would be in the judicious use of these FM simplex links. But it's not as if any bozo can establish a link to a particular repeater without consideration of the consequences. The repeater has to allow them access to their node or conference server in the first place. All of these links are clearly identified by the Echolink software by their "-L" suffix. Ideally, only those links that serve a constructive purpose should be allowed access, and it would be the trustees of that repeater that would make that determination. We already place broad trust in repeater owners to act responsibly, and we enforce that through the MRC co-ordination functions.

Rather than fear-mongering and wringing their hands, the MRC should make a constructive move to designate specific channels for shared use of this sort. Remember, these simplex link channels can be used for normal FM simplex activity when the linked repeater is inactive. Further recommendations might include limiting this use to a certain number of hours per day, or to 50W RF output, should problems be created.

There is a way to make this work, but living in a paradigm of what amateur radio was thirty years ago is a dead end.