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

Gould Smith gouldsmi at bellsouth.net
Sun Jul 6 10:48:24 PDT 2008

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.

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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