I have been doing some RFI hunting today, in order to find some of the noisy switch-mode power supplies in the appartment.
I found a rather noisy one (cheap "universal" laptop supply) with wideband "carriers" every 70 kHz and the noise level dropped considerably when that one was disconnected.
I have been considering replacing as many as possible of the switch-mode PS's with linear regulated ones, because it is far too noisy here, Maybe not worth it, since some neighbours probably have some noisy ones as well.
In any case I am enjoying the little bit more quiet environment here.
It is far from over yet, but a good beginning.
"The Art of Electronics" #8 -- Why Not a Simple Emitter Follower as The AF Output Circuit? - Click on the image for an easier read *Back when Dean KK4DAS and I were trying to find a suitable AF amplifier circuit for our High School Direct Conversi...
4 hours ago