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A compact 1:1 Choke Balun with decent power handling, for less than $50

Here is a simple weatherproof choke balun, capable of 100w+ power handling, compact in size, neat looking and low cost.

A while back, I decided to experiment with some dipoles for use on HF (being as I only have a small yard, I was working on 20m and up at the time). Anyway, I went looking around on the net for a 1:1 Balun to feed my dipole with, and I found a few, but the prices that I observed were around $50 and up. I decided that I would visit the local gadget store (Jaycar) and see about making my own balun, using some RG58, 2 large ferrite toroids, an SO239 Panel Socket, some Eyescrews, 2 Gold plated Speaker Connectors, some silicone sealant, a few Zip Ties, and a weatherproof box from Jaycar.

This is what I came up with, and it cost me about $35 (considering that I had some of the bits already laying around)


As you can see, it is just a matter of winding 6 turns of RG58 through 2 large ferrite toroids (Ferrite -is- your friend), and connecting one end to the SO239 panel socket, and the other end to the 2 speaker connectors. The Eye screws on either side take the tension of the wire, (so it doesn't pull out from the connectors), and the one at the top can be used for suspending the balun itself in mid - air if need be. The box is made water tight using clear silicone sealant. This balun will work on all HF bands from 160m through to 10m (and it will probably be fine on 6m also - I haven't tested it there). It will handle 100 Watts and up without a problem. For higher power handling (for those of you with big footwarmers - HI) you can add more ferrite toroids, and just use a slightly larger weatherproof box, but this will increase the cost of manufacture.

73 from Jamie, VK2TIM

(Re-published with author's permission)