[TowerTalk] Wireman Balun kits

[Tom McDermott]

There are several possible failure modes for baluns. Besides those involving the magnetic core material, high SWR can lead to excessive voltage between the windings. Tom, W8JI has written about that in the past. Several suppliers will sell you teflon tubing that you can use to sleeve the formvar wire in the balun to significantly increase the breakdown voltage.
  (One advises to select teflon tubing one size larger than your wire because it's otherwise hard to pull in over the wire). I don't have the links immediately available, but will try to find them and post.
   
  Additionally, balun loss is affected by mismatch. Jerry Sevick has written a lot about matching the winding impedance to the operating impedance, and the significant impact that it can have on the loss of the balun. Sleeving the wires with teflon will change the impedance because the two wires are slightly farther apart and thus the impedance increases.
   
    -- Tom, N5EG
   
   
   

       
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