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From: John Rabson <john.rabson@numeo.fr>
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Date: Sun, 4 Mar 2012 13:35:54 +0100
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To: rsgb_lf_group@blacksheep.org
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Subject: Re: LF: Short burst of DK7FC on 137
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On 4 Mar 2012, at 12:08CET, Stefan Sch=E4fer wrote:

> Hi John,
>=20
> 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.  =46rom 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