On 4 Mar 2012, at 12:08CET, Stefan Schäfer wrote:
> Hi John,
>
> Any further details or a screenshot?
Unfortunately not. I had just come into the shack and noticed your call sign
disappearing off the Argo display. From the contrast I would guess that it was
between 30 and 40dB over the noise, but I did not have time to measure it.
I now have the monitoring receiver running again, with usually two invocations
of Argo looking at different aspects of 137. I have looked at monitoring WSPR
simultaneously, which is possible when the required receiver audio output
frequency is 1500 Hz, but when people work at the lower end of the band I have
to retune and I can then no longer satisfactorily display the higher
frequencies.
You recently mentioned that you were using an H-Bridge amplifier for 137, but I
seem to have lost the details. Could you post them again, please? I am finding
that I am rather good at blowing up class E PAs and think I should look for
something that is rather more robust (and more tolerant of variations in load
isimpedance).
73
John F5VLF
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