More Satellite Stuff

  As you may know, the Fox 1-A FM satellite launched this week. The orbital data (Keplerian elements) have been announced, and it's showing up on apps and AMSAT's predictive tool as AO-85. Locally, it looks like we have decent passes around 4 AM, 6 AM, 8 PM, and 9 PM. These are just vague approximations, of course, so you'll need to look up the specific times. Still, I'm seeing passes lasting 13, and even 15, minutes. That's actually very good for satcom work. 

  AO-85 isn't ready yet, even though it's in orbit. You can listen for the CW beacon if you have an all-mode radio, and that should give you some practise spotting and tracking it. Per AMSAT:

Initial Commissioning Period: Initially the transponder will not be on and will not respond to uplinks. Please do not attempt to uplink while we check out the satellite and commission it. We will publicize when we have opened the transponder to general use. You should expect the checkout phase to last for a minimum of several days and possibly for several weeks.

  Please don't be that bozo interfering with the testing. 

AMSAT has also released a guide for working this satellite. It's very good, and you should read it, especially if you haven't worked satellites before. You should also find out your grid square ahead of time. There are Maidenhead calculators online, but you can also use aprs.fi for this. Just place the cursor over your location, and the grid square will show up in a box at the upper left part of the screen (e.g. EN34kv). 

  As the guide points out, QSOs on "birds" are very brief. This isn't just because the satellite pass is short, but also because there are a lot of people trying to use the (single) frequency. You basically are limited to exchanging your callsign and grid square. An example QSO is included in the guide. 

  More power doesn't help you. No more than 5W is recommended. Getting in to a "bird" is not particularly hard. The tough part is hearing it. On every pass you will hear clueless idiots blasting away, unable to hear anyone responding to them. Don't be that guy. Never transmit unless you can hear the satellite. The satcom community is not that large, and you will quickly get a reputation as an idiot that will be hard to shake if you are inconsiderate. Listen, then talk. That's good advice for any satellite, not just AO-85. 

  Another FM satellite that I haven't mentioned before is LilacSat-2 (CAS-3H). This one only operates every other day. In local terms, the FM side is on Sunday between 9 PM and 9 PM Monday, 9 PM Tuesday to 9 PM Wednesday, and 9 PM Thursday to 9 PM Friday. That doesn't mean that it's over our area for that whole time, though. Locally, we have decent passes around 7 PM and 8 AM. So you won't be able to use it at 8 AM on Thursday, for example. You will be able to use it for the 8 AM pass on Friday, though. Again, these are vague approximations. Today's pass was at 7:53 AM and lasted 12 minutes, for example. There are other passes, but they're generally pretty low and short. You listen on 437.200 and talk on 144.350 -- with adjustments for Doppler, of course. It's also interesting to note that LilacSat-2 is an APRS digipeater that runs on the standard 144.390 frequency. It's possible that you could end up working this "bird" and not even know it by using APRS. I'm still trying to find the SSID being used.

  There are also five new Chinese XW-2 satellites. The information on these, including frequencies, can be found here. These aren't FM satellites, and you'll need an all-mode (SSB) UHF/VHF rig to talk on them. You listen on 2M (145 MHz), and talk on 435 MHz. You should also be aware that, like all non-FM satellites, the transponder inverts. If you transmit on LSB (lower side-band), it will come out on USB (upper side-band), for example. 

  The XW-2 satellites are somewhat controversial because they operate (in some cases) out-of-band. The MN two-metre band plan specifies 145.50 - 145.80 for "Packet, misc and experimental" uses. The CW beacons of XW-2A, XW-2B, and XW-2C operate on 145.660, 145.725, and 145.790, respectively. Likewise, the transponders (SSB) of XW-2A and XW-2B operate outside of the designated satellite sub-band of 145.80 -146.00 MHz. XW-2C operates right on the lower edge of the sub-band. Listening to them, obviously, is completely okay.

  Realistically, I'm a bit sceptical of such low-power (and brief) transmissions causing any problems. But, if you are quite the stickler for the rules, then you should avoid working XW-2A and XW-2B. And if you're fond of pointless arguments, this offers ready-made fodder. Either way, these five satellites only have a predicted life on one year, so the shelf life for such outrage is kind of limited. 

   Locally, XW-2D has its best passes just before 7 PM and 8 AM. The other four satellites fall in the same general time slot, with 12-minute windows being common. The two best passes are significantly higher than 45 degrees at their peak, and should be suitable for those with otherwise-obstructed views. 45 degrees is, of course, the midpoint between the horizon and being directly overhead.

  Over the next few months, at least two more Fox FM satellites will be added. And, at some point, the FM satellite EO-80 will be turned on. SO-50 is still around, with three good local passes a day, though one of them is around midnight. There's still strong hope for an HEO (High Earth Orbit) satellite over the next few years, too. This would have passes lasting over an hour (and maybe two), but would require specialised antennae to reach further.  

  Working FM "birds" is something that you can do with a cheap HT, though having two is easier (one for RX and another for TX). Once you get the hang of it, you can do it by yourself. But it's intense, because you need to keep that antenna pointed (and rotated) while adjusting your TX and RX frequencies for Doppler -- and listening at the same time. Working the SSB satellites can be done with something like the FT-817ND rig. And you can also practise tracking with the CW beacons on both FM and non-FM "birds". Keep in mind these satellites cross the sky in only a handful of minutes, so tracking them with a hand-held beam is a skill. Practise this skill before you try to make a contact. Since the polarisation is constantly changing throughout the pass, you need to rotate the antenna for the best signal, too. You'll get a feel for a particular "bird" fairly quickly, and get the "twist-and-swing" move down after a few passes. If you're smart, you'll hold off transmitting until you learn how to keep a lock on a satellite.

  I really recommend picking up a dedicated dual-band satellite beam (Elk or Arrow), unless you just want to listen in. Even then, a UHF beam (for SO-50 or LilacSat-2) or two-metre beam (for the Fox satellites) is very, very helpful. Remember, hearing the satellite is much harder than reaching it. A three-element UHF Yagi is pretty small, and will probably make the difference between disappointment and excitement when listening to satellites. Making a Yagi for either band is hardly a daunting project, and tuning something like that is much less critical if you're only using it for reception. The guy who was selling the VHF tape measure Yagis on Ebay has stopped making them, unfortunately, or that would your cheapest and easiest option for the Fox satellites. 

  If you insist on using an HT antenna, point it downward at an angle and sweep it as the satellite passes. I've had only marginal success with this technique for reception. As you'd expect, it works better for transmitting (though still not great). Again, don't transmit if you can't hear the signal.

  For Technicians, working FM satellites is probably your best chance for DX, especially as we move into solar minimum on HF (and considering the need to use CW). Just bear in mind that it's not a conversational affair and that there are brief, specific times that you can do it. Even apartment-dwelling hams can set up portably in their neighbourhood park and show off their skills to amaze non-hams for the cost of a beam antenna.