[amsat-bb] Can't digipeat APRS thru satellites

Robert Bruninga bruninga at usna.edu
Wed Jul 15 15:18:58 UTC 2015

How are your tones?  About 90% of the packets on the air are overdeviated,
distorted, skewed, unbalanced, not properly emphasized or demphaasized or
neither.  These work "fine" terrestrially when weak signals are not involved
but may be 20 dB or more away from good performance with weak signals or
picky receivers.  I can decode PSAT with 5 bars on the Kenwood TH-D72, but
have no other experience to compare.  I remember good balanced tones did 3
bars on a D700, but typical bad terrestrial signals would not decode
sometimes with all 9 bars!

The ear can tell between good tones (listen to ISS) and bad tones (listen to

We have a bgighawatt experimental air defense radar near Wash DC on tethered
balloon blasting out power at 143 and 149 mHz and all over the place.  I
wonder if PSAT gets overloaded by that?  PSAT does not listen to carrier
detect, so when it has a packet to send, it sends it.


-----Original Message-----
From: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Mark Johns
Sent: Wednesday, July 15, 2015 9:23 AM
Subject: [amsat-bb] Can't digipeat APRS thru satellites

My packet setup gets digipeated instantly on terrestrial APRS networks, and
works fine with ARISS, but even with overhead passes on NO-44 and NO-84,
when I copy the birds well, I can't manage to get an APRS packet digipeated.
Even if I crank the power up to 50 watts, using the M2 LEOpack antennas,
those birds simply are deaf to me. I'm sending to CQ via ARISS, as my
reading of the online docs seems to indicate that is appropriate. I've also
tried CQ via PCSAT-1 and CQ via PSAT (for NO-84) but still no joy. I've also
played with TX delay. Nothing works. What am I doing wrong? -- Mark D.
Johns, KØMDJDecorah, Iowa USA
EN43----------------------------------------------- "Heaven goes by favor;
if it went by merit, you would stay out and your dog would go
     ---Mark Twain _______________________________________________
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