HFU HF Underground

Technical Topics => Equipment => Topic started by: ChrisSmolinski on December 30, 2021, 1320 UTC

Title: Parallel LC MW Notch Filter
Post by: ChrisSmolinski on December 30, 2021, 1320 UTC

A quick and dirty parallel LC notch filter to cut down local pest WHVR 1280 AM by about 20 dB on the 250 ft V Beam antenna, it was overloading the KiwiSDR now and then. Made with some junkbox components: 1800/680 pF mica caps in parallel with about 6.2 uH from the variable inductor.

(https://i.imgur.com/jHGidhs.png)

Title: Re: Parallel LC MW Notch Filter
Post by: M R I on December 30, 2021, 1909 UTC

Nice. Just enough to bring down the signal around one frequency.

Title: Re: Parallel LC MW Notch Filter
Post by: ~SIGINT~ on December 30, 2021, 2349 UTC

OMG - look at all that connector loss and potential leakage :)  Sorry Chris, I was a broadcast engineer, facility designer and also engineered comm circuits for the military - LOL