In Reply to: TV UHF Yagi - balun required? posted by Steerpike on February 17, 2009 at 13:19:59:
From what you describe, it appears that your antenna was designed to drive 75 ohm unbalanced coax directly.
Originally, most TV antennas (and sets) used 300 ohm balanced twinlead which had very low loss BUT had its own installation / longevity problems. As cable TV systems developed, twinlead was then replaced by 75 ohm cable - which required some kind of impedance transformation (4:1) to work with antennas designed for 300 ohms.
You don't (appear to) need a balun for impedance transformation purposes. So maybe the "balun" question becomes whether putting in a 75 ohm, 1:1 balun so that your antenna will see a balanced load will work better. Probably not worth the effort. Depending on how old the coax is it might very well be worth replacing that also - weather does a tune on coax.
Charles
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Follow Ups
- RE: TV UHF Yagi - balun required? - stellavox 02/18/0904:11:36 02/18/09 (1)
- RE: TV UHF Yagi - balun required? - Steerpike 12:55:39 02/18/09 (0)