[Elecraft] BL-2 Balun Heating

[Don Wilhelm]

Gary,

Balun heating is normally caused by attempting to feed a very high or 
very low impedance.
Have you tried the 4:1 position?  It may help, so do try it even though 
I would believe the antenna system feedpoint impedance where the balun 
is connected may be in the range of thousands of ohms rather than being 
in the 'hundreds of ohms' range that a balun can normally handle.
Another thing to look for is a shorted or open feedline or feedline to 
antenna connection.

You may want to try adding or subtracting some length to your antenna or 
to your feedline.

If you had mentioned the band(s) where this situation occurs, we might 
have been able to offer more insight than my generic response provides.

73,
Don W3FPR

Gary Winkelman wrote:
> I recently built a BL-2 Balun.  It is connected between my Palstar AT1KM 
> tuner and my doublet antenna.  The antenna consists of a 100' wire up 
> 25' and fed by 95' of 600 ohm open wire feeder.  I'm using the 1:1 
> setting on the balun.  There is a 4" section of RG-213 between the balun 
> and a coax input of the tuner.  I'm driving it with 125 watts from a 
> TS-850.   After no more than a few minutes of CW or RTTY transmission, 
> the balun is too hot to touch, the SWR rises and the power goes down.  
> The balun is obviously saturated. 
>
> Does anyone have an idea how I can reduce the overheating?  I've tried 
> adding a heat sink but it doesn't make any difference.
>
> Tnx for reading!
>
> Gary  N2UM
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