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

Re: ao40

"Malcolm M. Preston" wrote:

> The time is 1230Z, 20 Jan.  I appear to be receiving my strong signal on
> ao40 with minimal power (5 watts) on 440 up.  Stronger than the beacon with
> no leila or anything.  My dial indicated frequencies uplink 435.713.5 and
> downlink 2401.220.7.  The signal is s9, strong and steady.  No responses.
> My antenna is pointed az 102 deg, el 31 deg.  Range is about 38000 km.
> What I get is not AO10 which is up to the SW.  The signal has none of the
> AO10 qsb.  Am I nuts??  I can't figure anything else out this could be but
> ao40.  Unfortunately, I can't stick around longer this morning for other
> obligations.

    I'm guessing that you are actually hearing your uplink as a spur, birdie,
image, or some combination of these.  A couple things make me suspect this.
First is that with a signal stronger than the beacon, Leila should come after
you pretty soon - note I said should, not necessarily would.  Second is the
frequencies don't really quite match up - MAYBE.  I say maybe because as we all
know, there is a huge difference in downconverter accuracy, temperature drifts,
etc.  However (at least according to the cheater chart I use for my
downconverter), you are about 45 KHz off frequency.  Lastly I would be suspect
of 5 watts producing a signal greater than the beacon unless you have a really
great antenna system.  Granted it takes quite a bit less power at that range
than near apogee.
    Easy way to check is to wait until AO-40 is below the horizon, or point
your antennas well off the satellite and see if you still hear your uplink.  If
you do, obviously it's not being heard through the bird.

Jim Walls - K6CCC
626-302-8515    FAX  626-302-7501
AMSAT member 32537 / WSWSS member 395

Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org