[TowerTalk] Fair rite materials for choke baluns

[Jim Brown]

On Mon,7/4/2016 12:01 PM, Jeff AC0C wrote:
> The G3 data on the type 52 looks pretty good.  It sure seems like a 
> side by side bench test of the two materials would prove to be very 
> interesting. 

I'd be more interested in a study of power handling, which is a lot more 
difficult. A good starting point would be NEC modeling using the 
parallel equivalent circuit, which should give us a handle on the 
dissipation. Then subject the actual chokes to high common mode voltage 
to see how they hold up.

An easy to build test fixture would be to use the choke as the end 
insulator of an end-fed center-fed dipole, as I've shown a couple of 
places, and shove high power at a high duty cycle into the dipole. That 
test hits the choke with rather high common mode voltage. Blast it for a 
while, then go feel it for heating and inspect it for any damage. The 
choke in question seems to be resonant in the range of 15-20 MHz, so a 
suitable dipole should be easy to rig.

http://k9yc.com/VerticalDipole.pdf

73, Jim K9YC