Best APRS satellite?

Discussion in 'Satellite and Space Communications' started by KM6LYW, Feb 11, 2018.

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  1. KM6LYW

    KM6LYW Ham Member QRZ Page

    The ISS APRS radio has been down for 67 days. I tried Parkinsons/NO-84, but packets were weak and infrequent.

    Any other working APRS choices? I like to keep an option or two in my logbook in case I need to send an emergency email or sms from the sierra nevada mountains.

  2. WD9EWK

    WD9EWK Ham Member QRZ Page

    Right now, the only regularly working satellite for packet or APRS would be FalconSat-3. Unlike with the ISS or NO-84, you need a radio capable of 9600bps packet, and where the TNC can function on more than a simplex frequency (FalconSat-3 uses a 2m uplink and 70cm downlink). Kenwood's TH-D72, and the previous TH-D7A(G), are HTs capable of working this satellite.

    NO-84's digipeater is occasionally switched on, but it goes off whenever its battery voltage drops below a certain point. The primary mission for this satellite is the 10m/70cm PSK31 transponder, and the 145.825 MHz digipeater is secondary. There are telemetry beacons heard on 145.825 MHz even when the digipeater is off. Look for the call sign PSAT to know the digipeater is on. Seeing packets from PSAT-1 means the digipeater is off.

    NO-44 is still in orbit and operating around 145.825 MHz, but it is so old that it barely gets enough power from its solar panels to send an occasional beacon packet. It has been over 3 years since I last made a QSO through NO-44. I would not think about relying on this satellite for anything.

    Otherwise, you're still in the same boat as you were when you previously asked about this. If you don't have coverage from the terrestrial APRS network on 144.390 MHz or any other packet frequency in that area, and your mobile phone doesn't work where you go, you would probably want to consider other options like a satellite-based beacon or other communicator.
    K8TDN, KA0HCP and KA2CZU like this.
  3. KM6LYW

    KM6LYW Ham Member QRZ Page

    WD9EWK, awesome answer -- thanks a million. I'll try FalconSat-3, using an FT1DR. It has one modem on VFO-B, but I guess i can jump back and forth between VHF and UHF. Are there any sat-gates in the Western United states listening on UHF? fwiw, I don't own a cell phone, and I noticed Garmin has a fairly new satellite (iridium?) "texting" device with a pay-as-you-go service (for backpacking trips).

    Thanks again. I'll give FalconSat-3 a try.

  4. KM6LYW

    KM6LYW Ham Member QRZ Page

    and just to confirm, for me and possibly the next guy:

    435.103 down
    145.840 up
    9600 baud

    aprs digipath is... PFS3-1?
  5. WD9EWK

    WD9EWK Ham Member QRZ Page

    You can try to change that VFO between VHF and UHF, and be ready to tune the UHF frequency to deal with Doppler for FalconSat-3. W7KKE in Oregon has a satgate that has been listening to FalconSat-3. I think that is the only one that has regularly been listening for that satellite. You'd have to get your packets through early in the passes when you and Oregon are in the footprint, since that station will quickly leave the footprints on many passes. As for the frequencies and packet path, you were correct in your other post.

    If you are going places where amateur radio communications are not good enough, it might be time to consider either a mobile phone (if the coverage works for your travels) or something satellite-based. Gabe (now AL6D, previously NJ7H and other US calls, and also holds the Canadian call sign VE6NJH) traveled to the Canadian Northwest Territories last year, taking two satellite-based communications devices along for the trip. One of those used the Iridium network, and the other used the COSPAS/SARSAT system and also had a 121.5 MHz transmitter. Gabe drove well north of solid coverage from the Canadian mobile phone networks, and even used the Iridium device to regularly send his logs back to the US for uploading to Logbook of the World. Hams were getting confirmations for working Gabe via satellite, while he was on the road up there! This was written up as an article in last July's QST: Month in QST/July2017/Zeifman Promo.pdf

    This article explains the preparations Gabe made for a trip that far north, in the middle of winter.

    Good luck!
    KM6LYW likes this.
  6. KM6LYW

    KM6LYW Ham Member QRZ Page

    Confirmed up and down. Thanks again for the falconsat3 hint. Next test will be an aprs message relay, assuming something on the ground relays.

    2018-02-17 22:36:15 UTC KM6LYW>SXUTWQ,PFS3-1*,qAR,W7KKE-14

    This satwatch site seems up to date and includes falconsat3 traffic:
  7. W5WTH

    W5WTH Ham Member QRZ Page

    With my D72A and a whip I could not hear packets; squelch was OPEN on BAND A. The pass was 40 degrees at transit.
    Is a Yagi required?

  8. WD9EWK

    WD9EWK Ham Member QRZ Page

    FalconSat-3 had a crash, and its system needs to be reloaded by AMSAT command stations. This will take a few days, so come back to this satellite when it is up and running again.

    Some have received it, and even digipeated through it, with a long whip on an HT. A directional antenna is recommended if you want to do more than receive its downlink.

    KM6LYW likes this.
  9. W5SAT

    W5SAT Ham Member QRZ Page

    You won't really be able to hear the 9600 FSK packet data - It just sounds like regular background noise. 1200 bps AFSK has a very noticeable sound but 9600 sounds like hiss. Look at your signal strength and turn on the 9600 APRS on the D72 and see if you capture anything. It's a pretty strong signal and constantly transmitting.
    KM6LYW likes this.
  10. WD9EWK

    WD9EWK Ham Member QRZ Page

    Right now, you won't capture anything from FalconSat-3. It had a software crash after a long time of running without problems. AMSAT command stations will need to reload the satellite's operating system, which will take a few days at best. What you describe as the sound of 9600bps packet - like regular background noise - is a good description. When you work FalconSat-3, you learn to tell the difference between the ordinary noise and the 9600bps data downlink.

    KM6LYW likes this.

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