[amsat-bb] Re: Full Duplex?
John M. Belstner
jbelstner at yahoo.com
Wed Jul 27 10:25:38 PDT 2011
Others have answered the question quite well. One additional point I'd like to
make is how important it is to actually listen to your yourself on the downlink,
for a couple reasons.
1. On an FM bird, if you can't hear yourself or you hear a double... Stop
2. On a linear transponder (CW, SSB), use only enough uplink transmit power to
be heard on the downlink.
For #2, the rule of thumb is to compare your downlink signal strength to that of
the satellite's beacon and adjust your uplink power so your downlink does not
exceed that. A satellite PA can only put out so much power (say 1W). So if
your uplink is 20 dB stronger at the satellite than anyone else's, your downlink
could be transmitted at .99W leaving only 10mW for the rest of the QSO's in the
John Belstner W9EN
Valley Center, CA DM13le
----- Original Message ----
> From: Mike <mikef1234 at buckeye-express.com>
> To: amsat-bb at amsat.org
> Sent: Wed, July 27, 2011 5:25:49 AM
> Subject: [amsat-bb] Full Duplex?
> I'm having a difficult time of understanding the concept of Full Duplex. Can
> anyone explain it to me? I have the ARRL satellite book, read about it in
> there and Wikipedia. I still didn't understand how it works with a
> transceiver setup like we use.
> Mike N8GBU
> Sent via AMSAT-BB at amsat.org. Opinions expressed are those of the author.
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