Quoting Mika OH8MBN ... a 6dB difference between mode-B and mode-C wouldn't show the difference between a S7/S9 and a barely audible signal.
Quite right! Mika. I don't think the satellite was in mode-C at all, I believe it was in mode-B ... but creeping along the "grey line" and therefore *NOT* getting enough sunlight to power the transponder properly.
Taking into account the age of the solar panels ... (31 years) ... it's a safe bet that they are *NOT* producing anywhere near what they did in 1974. It's anybody's guess exactly how many watts the mode-B transponder is producing these days.
I'd estimate that mode-C would be totally inaudible these days unless you were using an EME class receiving system, however, I am open to debate on this particular point. I have been using QRP for 40 years now and am fully aware of what can be done with decent aerials but it should be remembered that AO-7 is *NOT* equipped with a large array when considering my comment re: power.
73 John. la2qaa@amsat.org
At 11:18 AM 10/9/2007, you wrote:
Taking into account the age of the solar panels ... (31 years) ... it's a safe bet that they are *NOT* producing anywhere near what they did in 1974. It's anybody's guess exactly how many watts the mode-B transponder is producing these days.
Hi John, Very interesting reading all the comments on good old O7!! Keep them coming!! We need all the interest we can in multi-channel communications instead of the "2 user" FM one AMSAT-NA recently spent the money on...
I've mentioned on here before that Andy and I worked it 22 years apart, and I'm using the same antennas!! I don't "remember" that much of a difference in sig strength so I'm going to GUESS that my present homebrew pre-amp is better than the homebrew one I was using then..
But certainly not doubting that AO7's power out has been reduced....
73, Dave wb6llo@amsat.org Disagree: I learn....
Pulling for P3E...
participants (2)
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Dave Guimont -
John Hackett