[amsat-bb] PSAT- transmission sequence

Tom Schuessler tjschuessler at verizon.net
Thu May 28 04:19:13 UTC 2015

The original email from David, reprinted below noted the "Stopping of the
435 downlink carrier and Bob WB4APR came back and said that the transponder
is in an "Auto" mode which waits for a PSK signal and then turns on.  My
experience the other morning was that this was true, but as David says
below, he was surprised by it turning off periodically.  My surprise was
that I was able to repeatedly turn it on when I started transmitting on
28.120 +1Khz, but before my CQ ended, the carier would quit.  I repeatedly
brought it up and also saw other not so copyable psk carriers on the
waterfall but the transponder seemed not to stay on long enough to keep a
full QSO going.  I know for a fact because I duplicated at least three times
turning on the FM carrier about 2-3 seconds after I started to uplink.  I
personally have yet in my several feeble efforts, been able to make a full
QSO although I have been emailed by several to say that they did indeed hear
me.  This morning, 5-27 1207Z pass I was bad and had my RX radio to the
wrong frequency but will give another shot at the 114xZ pass on 5-28 to see
if I can make progress on making a Q.

Tom Schuessler

-  -  -  -  -   -   -   -   -   -   -

Date: Wed, 27 May 2015 09:54:23 -0400
From: David G0MRF <g0mrf at aol.com>
To: bruninga at usna.edu, amsat-bb at amsat.org
Subject: [amsat-bb] PSAT- transmission sequence
Message-ID: <14d95a711a9-c2e-8cd at webprd-m108.mail.aol.com>
Content-Type: text/plain; charset=utf-8

Congratulations Bob and USNA on another successful spacecraft.

I listened for the first time this morning and could hear the beacon and
transponded PSK31 without any trouble.

But I was not expecting the 435.350 carrier to stop every now and again. 

What determines if the carrier is on or off. - Beacon timing.- OK, but is
the transmitter also PSK activated in someway? Or is it a timer.
Very nice for saving power.


David  G0MRF

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