Build Simple Effective Common Mode Choke For Antennas.
If you're bothered by RFI in your ham shack, you may want to build this easy common mode choke for your antenna systems. In this video, Steve Ellington (N4LQ) takes us step by step through the design, construction, and testing of this useful antenna accessory. If you can't see the video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=UP6G7PYyZHg. Here are a few comments from Steve (N4LQ): These chokes are as good or better than most anything on the market and much cheaper! Most commercial units use tiny ferrite sleeves or beads crammed into a PVC pipe. These have higher impedance and can handle outdoor use. Fair-Rite part number 2631803802 For RG8x or RG8M keep power under 500 watts. This assumes a 1:1 SWR. For higher power or high SWR use RG-400 coax. See link: https://rover.ebay.com/rover/1/711-53... If you use RG-400 you will have room to slide a piece of 3/4" or 1/2" PVC tubing through the center to devise a mean