[amsat-bb] Re: AO-73 Deaf again ????

Patrick STODDARD (WD9EWK/VA7EWK) amsat-bb at wd9ewk.net
Thu Mar 13 16:02:15 PDT 2014


I had replied directly to Peter earlier today, and we have had a nice
exchange discussing what he reported and what I saw on passes last
night.  I can expand on what I saw last night on two AO-73 passes...

The pass you referenced was a 58-degree western pass around 0535 UTC.
Unfortunately, I was the only one on the transponder (as W1AW/7), so
I did more tests with my transmitter power.  I was able to cut my power
down from 5W to 500mW and still hear myself loudly and clearly through
the transponder.  And it was nice outside (around 68F/20C at 10.35pm
local time).  The 145.935 MHz telemetry downlink sounded loud, but I
did not copy it with the software (my laptop was not out with me).

At 0401 UTC, an eastern pass with maximum elevation of 11 degrees
where I lose the first 3 or 4 degrees in that direction due to mountains,
I had a hard time getting through in the first couple of minutes.  I
heard a QSO on the transponder, and one station was very loud.  I was
able to finally hear myself at the center of the transponder, and make
one QSO (as W1AW/7) with CO6CBF.  I didn't move around to find the other
station, so my only QSO on that pass was with Hector.

For both passes, I used a pair of FT-817NDs, transmitting at 5W to my
Elk handheld 2m/70cm log periodic (except for part of the western pass
where I cut my power to 500mW).

The suggestion of trying VO-52 in particular is a good one.  If the
setup works for VO-52, it should do fine with AO-73.  I'll be on at
least one AO-73 pass this evening as W1AW/7 (0423 UTC, maximum
elevation 19 degrees), and - if anyone will be up for the later pass -
I will stick around for the 0559 UTC pass (maximum elevation 33
degrees).  Or maybe I will swap antennas on the later pass, going with
something other than the log periodic...



On Thu, Mar 13, 2014 at 3:20 PM, Paul Stoetzer <n8hm at arrl.net> wrote:

> Peter,
> Not any evidence from Europe, but WD9EWK reported good downlink
> signals from AO-73 on a westerly pass from his QTH in Arizona while
> running just 500 mW to an Elk antenna last night.
> The AAR29 AO-73 log page also reports several QSOs from Europe today:
> http://aar29.free.fr/sat/ao73/ao73log.php
> Have you checked VO-52 and AO-7 Mode B passes to rule out a problem on
> your end?
> 73,
> Paul Stoetzer, N8HM
> Washington, DC

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