[amsat-bb] AO-73 tonight at 02:58Z

Paul Stoetzer n8hm at arrl.net
Thu Aug 7 03:14:34 UTC 2014

Worked W5PFG and CO6CBF on the pass. Satellite sounded great as it
always does. With my Arrow and 2 FT-817s, I was able to locate my
downlink with the satellite at about 1.5 degrees of elevation. My
signal was plenty loud at about 2.5 degrees.


Paul, N8HM

On Wed, Aug 6, 2014 at 8:53 PM, Paul Stoetzer <n8hm at arrl.net> wrote:
> Good evening,
> I will be on AO-73 tonight at around 02:58Z, calling CQ at around
> 145.965 MHz. These passes usually don't have much, if any, activity
> and I'd like to drum up a bit more.
> The satellite will enter sunlight at 03:05:45, giving about 7 minutes
> of transponder time here in Washington, DC. I will be operating off a
> south facing balcony, so I will probably lose the satellite about 30
> seconds before the transponder shuts off.
> Tips for working AO-73:
> -Do not use computer control, the transponder frequencies are not
> stable and this will only result in frustration. Besides, manual
> Doppler control is much more fun than letting the computer do all the
> work!
> -I usually start a pass by trying to find myself come into the top
> edge of the passband (145.970 MHz). To do this, I usually start
> transmitting around 435.130 MHz and tuning up slowly until I can hear
> myself enter the passband. Then I can move around the transponder
> easily. Remember to tune your uplink to maintain an constant downlink
> frequency (the opposite of FO-29).
> -Keep power output down. The transponder has a very sensitive receiver
> and a very active AGC circuit. Excessive uplink power will not make
> your signal louder - it will only reduce that available for others on
> the transponder. With a clear view of the horizon, 5 watts to an Arrow
> or Elk is plenty for horizon to horizon coverage. Very slightly more
> might be necessary if you are beaming through trees or other
> obstructions, but try to keep power to 25-40 watts ERP.
> Hope to hear you on this evening!
> 73,
> Paul Stoetzer, N8HM
> Washington, DC

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