Hello All!
I have been eyeballing the line loss charts in the ARRL antenna book and
keep thinking that open wire line or twinlead would also be a super
low-loss feedline for VHF/UHF into 50 ohm antennas as long as I could take
care of the matching.
There is a neat article on this subject on the http://www.antennex.com
online antenna magazine (requires a subscription to read).
To summarize: For monoband applications, you can very easily homebrew 4:1
baluns from scraps of coax, as per the ARRL antenna book. These can be
encased in PVC. This provides a decent match at both ends for 300 ohm
domestic TV twinlead.
It seems to me that a 6:1 balun would be a perfect match. For 450 ohms
window line, you need 9:1. Does anyone know a simple way to build these
for VHF/UHF?
Antennex is a neat magazine for those who like to experiment with
antennas. They have a large archive of past articles.
Mark, N1LO, Gloucester, VA
--
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
|