[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Looking for AO-40



The beacon looks a lot like FSK on the spectrum analyzer...two signal
peaks about 400 Hz apart (or so...).
You will never see it on the spectrum analyzer because the NF of HP spec
ans is 31dB...and that's with 0dB RF ATT.  You will need significant
(>20dB) additional IF gain to get any response, and that only with RES
BW and VID BW set to 300Hz or less (which means annoyingly long scan
times).


Dave Bourne wrote:
> 
>         I received my 3733 downconverter from K5GNA (with all mods) on Saturday and
> have not been successful in hearing AO-40. I tried using my Conifer dish on
> Saturday Evening using the Conifer feed and nothing. On Sunday Evening I
> tried again using a 36" offset feed DBS type dish along the 3733 "dipole"
> feed and again nothing. I have a Spectrum Analyzer (HP 8558) and I see
> nothing when tuned to 144 Mhz looking at the output of the downconverter
> through the power divider. When I pan my antenna towards LA (I live in
> Southern CA) and tune up in frequency on the Analyzer I can see some
> "Wireless Cable" digital carriers coming through the downconverter. If I
> disconnect the downconverter from the analyzer the noise floor drops about 8
> to 10 db so I believe that the downconverter is working. I use Nova tracking
> software and it seems to work OK so I believe that I'm pointed in the right
> direction at the right time with my antenna.
> 
> 1. What type of modulation is used on the Beacon.? Should I see anything on
> the Analyzer ?
> 
> 2. On what frequency should I see the Beacon on (after downconversion) ? Is
> it something like 144.350 ?
> 
> Thanks
> 
> Dave Bourne WB8TMP
> Corona, CA
> 
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home