[amsat-bb] Re: AO-51 L-Band Packet Uplink

Edward Cole kl7uw at acsalaska.net
Sun Jul 6 11:28:51 PDT 2008


Gould,

Great feedback that you provide to users, thanks!

It will be a few more weeks until I get my satellite ground station 
re-erected.  I had a pretty good AO-40 station during that era and, 
with a house move in summer of 2006, I have not gotten it 
re-installed.  I do have the ten-foot tower installed (which hinges 
over to the ground for antenna installationor maint.), so I hope get 
to installing the antennas, sometime soon.  So, for now, I read the 
observations and comments with interest.

In time, I hope to be able to provide some telemetry reports.  I'm 
guessing that mode-LU mode and 9K6 telemetry require some good 
frequency auto-tune and auto-tracking capabilities for unattended or 
hands-off observations.  I hope to add that after the antennas and 
radio equipment are again operational.

We will look forward to Andrew's visit to the Alaska ARRL Hamfest in 
August to inform on latest happenings in Amsat.

73 Ed - KL7UW
http://www.kl7uw.com/sat.htm
http://www.akhamfest.com


At 09:48 AM 7/6/2008, Gould Smith wrote:
>I have the L band receiver off while I am doing testing on the transmit
>power level and battery discharge rate.  I updated the AO-51 message to
>reflect this. The charge and discharge rates appear to  have changed
>following the period of no eclipse that ended in April.
>As far as the digital downlink, you should be able to decode it without any
>problem if you are receiving a signal with a good S/N ratio.  I can tell a
>good deal of difference between winter and summer receive levels, because of
>foliage, but get everything well once above the trees. I get data when
>through the trees, but not everything.
>
>The transmit power has also been down due to the length of eclipse that
>peaked about 2 weeks ago and will continue to get shorter until Sept when we
>will see a no eclipse period for about 8 months.
>
>This morning I set TXA to 430 mW (digital downlink) and TXB to 470 mW
>(analog downlink). So pretty good power levels for both transmitters. A
>month ago they were in the 340 mW range.
>
>73,
>Gould, WA4SXM
>AO-51 command station
>
>----- Original Message -----
>From: "Rob Hardenberg PE1ITR" <rob at itr-datanet.com>
>To: <amsat-bb at amsat.org>
>Sent: Sunday, July 06, 2008 1:29 PM
>Subject: [amsat-bb] AO-51 L-Band Packet Uplink
>
>
> > Hi All,
> >
> > I'am trying to access AO-51 9600Bd packet uplink on 1268.700MHz but had no
> > succes so far. Maybe
> > someone on the amsat bb group has some experience on this?
> > I see on the downlink the message "Frames heard from PACB-1". I think it
> > means the receiver is
> > getting some signal but can't decode it.
> > I believe my 23cm transmitter is working ok with 10w output into 26el
> > yagi. Also the 9600bd is
> > working OK because I can connect to local stations.
> > I see no other traffic on the sat so it seems to me the L band receiver of
> > ao-51 is not to sensitive.
> >
> >
> > 73 Rob PE1ITR
> > http://www.pe1itr.com
> >
> > _______________________________________________
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>_______________________________________________
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