[TowerTalk] Telrex Balun

[Pete Smith]

At 05:49 AM 7/13/00 -0500, Greg Gobleman wrote:
>
>My Balun was shot also.  Inside the water impregnated box was a coil of RG8
>and a coil of maybe 14ga wire.  I replaced it with a choke, about 10 turns
>of RG213.  Now I really don't know the performance of the antenna before I
>acquired it.  But now the 10m portion is a MHz low and out of band.
>
>There was a discussion awhile back on the performance of the TH6/TH7
>antennas and what happens to them when the Balun is changed.  It would seem
>that there is a critical length or effect that a simple choke does not
>supply.  

If the 14 ga. coil was across the driven element, perhaps it was a hairpin
match intended to bring the feedpoint impedance up to ~50 ohms.  Why not
put a bead balun on the feedpoint temporarily and measure the feedpoint
impedance and center frequency with an antenna analyzer?  You might come up
with numbers that would tell you how to fix the match.

73, Pete Smith N4ZR

The World Contest Station Database 
is back up and running at
http://www.qsl.net/n4zr 



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