[TowerTalk] Tuning Yagi's w/ non-insulated elements ?

z.pitman@libertel.nl z.pitman@libertel.nl
Wed, 15 Mar 2000 10:14:05 +0100


Let me ask for your collective wisdom about this... 

At the local club we are doing some major refurbishment on the 20m Yagi's.
These Yagi's were built some 15 years ago using the dimensions given in the
W2PV book (6 el Long John design). Due to the local circumstances all
elements had to be grounded to the boom. Gamma matches were applied. The
only tuning those antennas had to undergo was a minor adjustment of the
driven element length through the gamma match. Despite of the complete lack
of serious measurement equipment we were confident about it's performance:
the SWR curve and bandwidth was OK, and the antenna earned several CQ and
ARRL plaques. 

Now these Yagi's are laying on the ground waiting for new rivets and new

My question is: How could/should I fine-tune yagis with non-insulated
elements once it's put back where it belongs ? I'd like to measure the sole
antenna only without any matching but have no idea what is the best way to
do it. This monster is too heavy to be handled manually and the
cherry-picker costs a fortune every hour..

Your input would be gratefully appreciated. 

73 de Zoli HA1AG

FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm