[TowerTalk] Telrex Balun

[Tom Rauch]

> Tom, your right, it's junk.  But when it was designed and built it was
> nearly state of the art.

State-of-the-art, even back then, was far beyond what they came 
up with.

The fact it actually unbalances the feed system quite a bit means 
you'd most likely be better off tolerating an SWR increase just to 
get rid of it. Of course a slight fiddling with the hairpin or driven 
element length and you'd have the entire problem solved.

What Telrex tried to do was wind a coil of RG-8 (not enough 
inductance in the coil, however) and then they used insulated 
single conductor house wire to wind another coil that went from the 
center conductor to ground. The two coils do not have the same 
inductance, and they do they have enough inductance. They also 
don't have unity coupling, or perfect isolation, and you don't want a 
ground referenced voltage source anyway even if they would have 
done the thing right.


73, Tom W8JI
w8ji@contesting.com

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