Am 10.11.2017 19:44, schrieb N1BUG:
I see a nice clean sine wave at the other side of the LPF.
With a good LPF, the output often looks quite good on a scope, even with
massively distorted input signals.
But I see a lot of RF (36 volts peak to peak) at the +13.8V power
connection to the PA!
Yes and your power supply doesn't like it, it can be damaged from the
high RF peak currents. Or the voltage regulator can do crazy things. And
BTW the current measurement is likely to be totally wrong with such an
AC component. With the coil you can decouple the AC component from the
supply, at least most of it.
Just take a piece of enameled cu wire, 1mm diameter, and wind a coul
with 15 turns on something with 15mm diameter. Or use a T106-2 core for
example. Of course the big C is needed as well. For the 1 uF cap i would
use WIMA MKP-10 or so. Without calculating i would say that this
improves things significantly.
73 and have fun,
Stefan
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