Sorry Uwe, missed to answer in all the trouble...
I didn't know that a JUMA TX is available for "500".
Well, the version for 137 kHz is fine but i think 60W is not really
enough for a ordinary LF amateur antenna. But on MF, 60W may be just
right if one want to strictly stay below the limitation of 1W.
Do you know how the PA is designed?
I'm just experimenting with a class D PA for MF but am surprised about
the "problems". I.e. i thought it is easier to build. The output C of
the FETs cause a heavy oscillation when the FET is OFF. So actually i
would prefer a class E which does not have this problem. A class E
would be really no problem, regarding the design. But i intend to use
it for various experiments, also with /p antennas, just for playing
arround. Here, a class E is not recommended at all since it needs a
very accurate match to Z=R=50 Ohm. Otherwise the efficiency is
decreasing dramatically, up to blowing up the FET...
73, Stefan/DK7FC
Am 27.05.2012 09:39, schrieb Uwe Wensauer:
What do You think about the JUMA TX500 TransmitterI
In my eyes a small Rig with 60 Watt and built in Converter.
By the way, have a look at the filters in use – easy to built an
duplicate
Uwe, dk1kq
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