[amsat-bb] CW straight key nowadays (and PSAT)

KO6TZ Bob my.callsign at verizon.net
Tue Apr 5 20:53:35 UTC 2016

Bob B,

I have one answer...

On the 20:10utc pass of NO-84 today, I turned on the FM transmitter and 
shortly after, saw a CW signal on the waterfall.  (source unknown) The 
result was "Zero" copy of the PSK-31 on the down link. This is the same 
outcome I have experienced using PSK-31 on FO-29 and other linear 
satellites.  One CW signal will disrupt PSK-31 operation.

This 'first' experiment brings up the question: does the pulsing of the 
CW signal disrupt the up link, down link or both ?  All prior testing 
was on LSB/usb satellites.  This was on a USB/fm satellite.

This test  needs to be repeated.


And also PSAT, with its 28.120 linear uplink and FM downlink. Although
someone has to be transmitting PSK31 for the auto-transponder to come up,
any weak CW in the same spectrum should be heard.  Although I should not
recommend such use, so as not to disrupt normal band plan operations, it
is a nice experiment and since the PSK31 transponder is usually never more
than about 5% loaded (1 user maybe?) it's a shame not to experiment with

-----Original Message-----
From:  Paul Stoetzer
Subject: Re: [amsat-bb] CW straight key nowadays

 > <snip> ...the following satellites have linear transponders available
for use:

[PSAT 28.121 up and 435.350 FM down.]

Watch your power on CW - especially on AO-7 [and PSAT]. A very strong CW
signal can make the transponder useless for others, and in the case of
AO-7, cause it to mode jump at certain times of the year.


Paul, N8HM

On Sunday, April 3, 2016, andy thomas via AMSAT-BB <amsat-bb at amsat.org>

 > Hi
 > Just sorting out the garden and antennas this Spring day. I have my
 > preamps wired into the feed lines and want to get on air with a
 > challenge a bit more than FM.
 > So I'm wondering what is currently available to work in CW (Only
 > straight key and I'm not very fast!)?  FO-29, I suppose, but anything
 > 73 de andy G0SFJ

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