Another possible if heat-sinking hasn't / doesn't save it,
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is to perhaps lessen the dissipation of the PA*.
The easiest being reducing the input voltage while using high duty
such a WSPR ??
* Class E output stages by their nature can be subseptable to
component failure through excessive Vs caused by many external
Inc antenna mismatch etc.
On 08/08/2018 23:36, Alan de G1FXB via
Is the warning contained in section 4.24 Beacon menu in the
assembly manual relevant?
On 08/08/2018 23:24, BobVA wrote:
On Tue, Aug 7, 2018 at 06:04 PM, Kent Vanderploeg wrote:
Just following up on my progress and to see if Bob
has had any luck getting his going again.
I'm afraid I'll not be much help. Replacing Q1-Q6 got me
back to about 3.5w into a dummy load on 20m at 14v (not a great
wattmeter, so take that with a grain of salt).
I then reconnected all the WSPR bits but unfortunately
forgot to peak my small loop on the WSPR frequency before
transmitting (it was close, but...), so that took out the finals
yet again (shorted this time).
I replaced just Q1-3 and Q6 again which got the RF back,
and then *carefully* set it and the antenna up for WSPR. It
transmitted happily for a couple of hours, putting out about
Then some other failure ensued that resulted in a blank
display. After a cycling power I had no RF again, so I'm
beginning to suspect I've either got another fault in the radio
that is causing the finals to fail, or it *really* doesn't like
something about my antenna setup.