[TowerTalk] VHF/UHF Common Mode Choke

David Gilbert xdavid at cis-broadband.com
Fri Jun 28 22:28:28 EDT 2019

Can you please explain how a T-Match eliminates the need for a choke?  
Fundamentally a T-Match itself is a balanced network, and unless you 
purposely unbalance it I don't see how it eliminates unwanted 
common-mode current.

And if you do purposely unbalance it in an attempt to eliminate unwanted 
common-mode current, how do you conveniently determine when you have 
done so?  You'd have to measure RF current on the outside of the shield 
at multiple points on the feedline while hoping you weren't contributing 
to detuning with your body.

Somebody smarter than me needs to explain all that before I buy it.

Dave   AB7E

On 6/28/2019 3:58 PM, Dave Sublette wrote:
> Using a T-match eliminates the need for a choke, for the most part.  I have
> T-matches on everything from 2M to 70 CM.
> Dave, K4TO

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