Use an unun not a balun if you're simply going from 50-Ohm antenna or
coax to 75-Ohm coax. Personalyy, why bother? 75 to 50 is a 1.5:1 VSWR.
You'll probably lose the same in a tuner or unun. I fed a Titan with 1/2" P-III
CommScope hardline with no problems. I spent the money and went with
commercial connectors (Gilbert). No adjustment or anything. I had 2:1 VSWR
or better at the transmitter.
73,
Bob AA0CY
----------
From: DavidC[SMTP:davidc@bit-net.com]
Sent: Friday, October 09, 1998 10:41 AM
To: towertalk@contesting.com
Subject: [TowerTalk] GAP Verticals with 75 Ohm CATV Cable and/or Balun
I am acquiring two used GAP verticals, a Titan and a Challenger. I have
asked GAP if they may be adjusted to work directly with 75 ohm CATV cable,
or through a balun, here is their less-than-helpful reply (obviously off of
a generic 'talking points' sheet):
"The Titan and Challenger should be fed with 50 Ohm coax. I'm not sure if
you can run the 75 Ohm with a balun on our antennas. If you have any other
questions, please let me know."
Anyone here familiar enough with the design of these things to offer a more
helpful response?
--
Thank You! & 73, DavidC AA1FA
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