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RE: Drake 2880 Problem with AO-40 ???



Jeff & all,

I have a 2880 with all of the mods and an R. Myers BBQ dish and no preamp.
I've been trying to receive the beacon over the last week with no luck
whatsoever.  I was starting to think that my Drake was deaf however, I do
get the usual noise level when I apply power.  I was so frustrated that
yesterday I finally took the 2880 into work and connected it up to an RF
generator.  I found the Drake to be working just fine and that I was about
1kHz high on frequency.

I've been reading the threads about squint angles and receive success, and I
am starting to believe that has to be the case in my situation.  I'm just
not listening at the right times (difficult when I live in an apartment and
my station is still at my parents house 25mi away).

>From what I've gathered on this reflector, it's better to listen at low
squint angles and close to apogee.  I've read quite a few threads about
being able to receive the bird much better at apogee than on its way there.
Last night (16MAY 0144 UTC) when I tried, the squint to me at AOS started at
18º and was decreasing, with a range around 34K miles and increasing.  I
stopped listening around 0300 UTC and at that time the elevation was around
12º, the squint was around 13º at a range of 36K miles.  Didn't hear a peep.

When I got home last night I connected up to the telemetry server and voila!
at least someone is receiving the beacon!  It's been very frustrating for me
so far but sooner or later I'm going to make that first QSO through AO-40!!

I hope this very long-winded answer helps in some way.  Just remember, it's
all about squint.  I'm still learning!

Regards,
K3TZ

-----Original Message-----
From: owner-AMSAT-BB@AMSAT.Org [mailto:owner-AMSAT-BB@AMSAT.Org]On
Behalf Of K7xq@aol.com
Sent: Wednesday, May 16, 2001 1:24 AM
To: amsat-bb@AMSAT.Org
Subject: [amsat-bb] Drake 2880 Problem with AO-40 ???


Hello All,
 In the wake of hearing about the AO-40 S-Band Transponder Output turned on
and having successfully received a few minutes of telemetry on a very low
perigee pass a few months ago, I decided to listen for signals from AO-40
recently. Unfortuneltly, the Drake 2880 does not appear to have sufficient
Noise Figure by itself and an external preamp looks like its required.

Is any one experiencing their Drake 2880 to be deaf ???
Is a external preamp required ???
If so, where can I get one with use with the Drake ???

I do know about a modification / Gaasfet device that can be installed in the
RF section of the Drake but did not consider installing it due to the fact
that there are reports that many are using the converter as is with no
problems.

The antenna is a 13 turn RHCP Helix. I understand many are using this same
converter and antenna and hearing/working the satellite just fine.

Jeff K7XQ

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