Hi Paul,
15:15 UTC on 136.175 kHz, i bet this was your signal! ;-)
Am 12.03.2016 08:48, schrieb Paul Nicholson:
Meanwhile, I rebuilt the filter using air cored coils and
it works great. A lovely 200W sine wave into the dummy load
and nothing gets hot! After a while the output transformer
is just slightly warm. DC in was 240W from a 60V supply and
it seems I don't need a cooling fan anywhere.
That sounds good!
A better RF ground is needed, there's some RF current going
to earth via the domestic ground which I'm not keen on.
So I'll put another transformer at the far end of the coax and
match the antenna/ground to its secondary.
That's certainly the best way to go, using an isolating transformer at
the end of the coax. Prevents you from unwanted currents through the
house / mains earth.
Which antenna current do you get at 100W?
The wire is 400m long and you need just 100 uH for tuning, right? What
is the average height above ground?
I've run out of
toroid cores so it'll be lots of wire wound round a bucket.
I know that problem and also order more then one if i need one, see
attachment :-)
73, Stefan
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