Re: HB VHF low-pass filter

Allisonnospam@xxxxxxxxxxxxxxxxxxxxxx wrote:


I've notched out a a local pager just using a coax T and a ~12-13"
open stub section of LMR400 (1/4wl @ pager frequency).


Allison

I'd try that first. I work in cable tv and one of our older methods of "scrambling" was to use an interfering carrier ~2 MHz above the video. It was fairly easy to use a little stub of coax and completely remove the jamming...ie >40db of rejection with only a few db hit on the video carrier 2 MHz away. In your case 7 MHz away it (insertion loss) will be a non-issue.
You'll find the stub length to be critical to about 5mm so its a true cut-n-try technique. Use some old scrap television cable for the stub so you don't waste the good stuff.

GL,
Bill



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