CW Filter QST December 1978 page #36

[@arkadybron1994]

I have no idea why this video popped up on my feed, but some context would have been nice.

[@K1OIK]

I make videos of what I am selling. Maybe you are a subscriber? Maybe you just got unlucky?

[@arkadybron1994]

@@K1OIK The point I was trying to make, is that your video only makes sense to people who already know what the unit is.
A little explanatory preamble might help people to understand, what it is you are talking about.

[@timsmith428]

I take it this is an audio filter? Audio out from the receiver through the box then into a speaker?

[@K1OIK]

It would seem so.