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Re: AO-40 beginner having some probs!



Hi Richard,

Don't give up!  Until you find the Beacon, you are dealing with
several unknowns at once, any one of which can prevent you from
hearing it.  These include the antenna Az and El, and the
Downconverter conversion accuracy (exact Local Oscillator
frequency).  I found that my Az calibration was off, and at the
same time, I was low in frequency from the predicted.  Scanning
around with either one of these was ineffective, since the other
prevented reception.

In my case I used the shadow of the sun on the back of the dish
to calibrate the rotor position (a compass is not good enough),
and now I have no problem finding the beacon with a little twist
of the radio dial.

One last suggestion is to be sure the satellite's beacon is on;
look at the P3D website to verify what phase it's enabled on, since
it's not on all the time.

Good luck,

Greg  KO6TH



>From: "Richard Mason" <info@m0exe.org.uk>
>Reply-To: info@m0exe.org.uk
>To: <amsat-bb@AMSAT.Org>
>Subject: [amsat-bb] AO-40 beginner having some probs!
>Date: Tue, 4 Jun 2002 14:21:33 +0100
>
>Hi Folks,
>
>Having spent some time gathering together all the necessary bits and 
>pieces,
>I finally have what I need to receive AO-40's S band downlink (2.4GHz).
>I've built a feed for an old analogue sky dish I had kicking about, and 
>have
>an AIDC 3731AA downconverter (both with thanks to Howard @ www.g6lvb.com).
>
>However, finally got around to testing the setup properly last night 
>(around
>00:30 GMT) when the bird was around 130 degrees/16 degrees elevation (from
>JO01KU).  So I hooked everything up, and plugged into my FT-726 (minus the
>mic for obvious reasons!).  Having powered up the 3731, I got about a 
>signal
>3 on the meter, which I believe to be rather lazy as this is a signal 9 
>when
>I switch from USB to FM.
>
>So, I proceed to tune around 2m, only to find absolutely nothing.  I went
>outside to wiggle the dish about a little bit to see if it makes any
>difference - still nothing!  I then detached the downconverter from the
>feed, and the signal 3 remained on the meter.
>
>I'm now left wondering whats wrong.  This is a brand new downconverter
>(which I haven't popped!), I know the FT-726 isn't a fantasic receiver, but
>I'd expect to be able to receive something even if its only weak e.g. the S
>band MB.  (I thought I had just about heard the MB a couple weeks back when
>the bird was on its way back, but I must have been mistaken).
>
>This could just be something stupid like the back-to-back N-Type connector
>between feed and 3731 is a poor contact, but I thought I'd post to the BBS
>to see if anyone had any other ideas?
>
>Regards,
>
>Richard
>M0EXE
>
>
>----
>Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
>To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org




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