Build Simple Effective Common Mode Choke For Antennas.

In this video, Steve Ellington (N4LQ) takes us step by step through the design, construction, and testing of this useful antenna accessory.

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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 means of support however the core / coax assembly is fairly strong anyway. You can put 2, 3 or 4 of these in series for an insane total of choking resistance. Just leave 6" or so between them and use a longer section of coax. If you want a minimum of connectors just use one long coax from the shack to the antenna and wrap a few of these along the path! Use the same cores for AC cords, DC, cords, Speaker cable, Mic. cable, rotator cable ....You name it. BTW: Don't waste your time on a so called "ugly balun" or coax just wrapped around a pvc pipe. They have almost zero inductance! If one actually seems to work it's probably because you added coax length and move the radiation to another spot :*) Good Read RFI and Choke building http://k9yc.com/RFI-Ham.pdf Have fun building 73 N4LQ

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Steve Ellington N4LQ

10.9K subscribers

Thanks for joining us today.

Aloha es 73 de Russ (KH6JRM).