Posted by Gedas W8BYA on April 03, 2026 at 15:17:52.

In Reply to: Re: Condx arrgh! posted by Glenn on April 03, 2026 at 08:27:22.

By all means do try out some type-75 or even better yet some type W or type J cores and wind at least 10-12 turns of any and all cables heading out to the antenna. One choke for the coax and one for any power or control or rotor lines. Put one right near the receiver antenna jack and another right near the antenna feedpoint. These will help with CM RFI quite a bit. One thing that really ticks me off is when you open up many of the asian products that contain power supplies etc you can clearly see they made room on the PCB for a half dozen EMI components but do not install them. All this to save 20 cents. They populate the PCB with these inductors & capacitor parts to pass EU and FCC requirements at the time of testing and certification but once they get a stamp of approval they no longer install these parts and ship them out by the thousands because they know nobody will do any spot checks on their products and they can get away with it saving themselves lotsa bucks (at our expense). As far as AC or DC power line filtering, when I was responsible for RFI control for military coms etc as a tempest engineer it was common for me to specify CM/DM filters made by Corcom or Schaffner, and other time trusted names. You can find units that start filtering below 1 kHz but they can get pricey. 73 Gedas W8BYA

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