[Amps] Wire

[Vic K2VCO]

Jim Brown wrote:

> The use of coax rated for high temperatures was part of the 
> original work published on common mode chokes (current 
> baluns) published by W1JR and W2DU. Further, it has been 
> shown (by W8JI, among others) that mismatch is NOT a 
> contributor to heating in a choke balun. Heating in a 
> current balun is proportional to the square of the common 
> mode current. An effective common mode choke (current balun) 
> will add a very high resistive impedance in series with that 
> common mode circuit, reducing that current to a small value, 
> and making dissipation small. 

My experience when feeding a balanced antenna with a common mode choke 
at the transmitter end is the following: reducing the reactive component 
at the balun terminals reduced heating. I am not sure why the common 
mode current would be affected by canceling out the differential mode 
reactance, so I am not sure this is the whole story.

-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco