Jerry, I saw absolutely nothing on the downlink. Static.
Mark Lunday, WD4ELG Greensboro, NC FM06be [email protected] http://wd4elg.blogspot.com
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of Jerry Pixton Sent: Sunday, December 13, 2015 8:44 PM To: [email protected] Subject: Re: [amsat-bb] NO-84...operator error?
Mark, et al
The PSK passband is about 3 KHZ. Your radio USB bandwidth may be the limiting factor.
Are you seeing the beacon at about 314 Hz if someone gets it keyed up?
I discovered today that if I just send idle tones (key up with no message) that the 31.5 baud detector circuit is much quicker to turn on.
I am confused by the question: Mark, what signal are you seeing in the psk waterfall? I assume this is a waterfall of the downlink audio? Then was this your signal?
If your radio uplink VFO is set at 28120000 Hz in USB, and I modulate with a 1500 Hz audio tone (however I generate it) I would expect to hear a 1500 tone on the FM or 1500 Hz on the PSK31 waterfall. This is ignoring any error in my uplink vfo and any translation error in the bird - both of which are real. The other big error is doppler.
But DopplerPSK is doing a reasonable correction of the modulation tone so that when you set a desired center frequency of 1500, you get close to that most of the pass with some noticeable error around TCA but still decodable. But if you are not doppler correcting your uplink signal all bets are off with the plus/minus 700 Hz tone shifts seen.
So I guess a test of how well your doppler correction is working is how close your downlink signal is to the target central tone you have set for the uplink?.
Jerry, W6IHG
On 12/13/2015 7:51 PM, Mark Lunday wrote:
Again I tried to send through AO-84. I was on 28120 with a tone of 1.5 kHz. I saw nothing on the 435.35 downlink. At all. The 1932 UTC was good enough that I should have seen something.
I was also not able to send a packet through on 145.825. How wide is the passband for PSK on the uplink?
Mark Lunday, WD4ELG Greensboro, NC FM06be [email protected] http://wd4elg.blogspot.com
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-- ----------------------------------------------- Dr. Jerry R. Pixton, PIXOS Designs http://www.shentel.net/pixosdesigns/RadioTuner/ [email protected] ----------------------------------------------- _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb