[RFI] Tower/Antenna Reradiation

[Jim Brown]

On 12/22/2021 11:07 AM, David Eckhardt wrote:
> Ultimately,
> an aggressive line filter (Corcom or equivalent) was installed with the
> case of the filter bonded to the metal support of the opener, itself, and
> that in turn bonded to the "ground" of the opener circuitry.  

A multi-turn ferrite common mode choke wound on a #31 toroid or through 
a #31 clamp-on would have likely solved the problem. #43 is the wrong 
mix below about 100 MHz.

http://k9yc.com/2018Cookbook.pdf
http://k9yc.com/KillingReceiveNoise.pdf

We also had
> to install several ferrites (43 material) with several turns through each
> on the lines going from the opener to the sensors at the bottom of the
> garage door opening.

73, Jim K9YC