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Re: [TenTec] which balun?

To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Subject: Re: [TenTec] which balun?
From: "Bob McGraw - K4TAX" <RMcGraw@Blomand.net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Sat, 27 Jul 2013 18:22:31 -0500
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
What is the impedance of the antenna at the feed point where the balun is connected? It most assuredly is not the feedline Z of 450 ohms. Unless the feedline is an electrical 1/2 wave then the feedline is then acting as a line section transformer. On some bands the actual feed impedance might be 25 ohms while on other bands as high as 2000 ohms. In each case, different baluns ratios would be preferred.

In both cases, I prefer 1:1 current baluns rated at 5X to 10X actual transmitter power. Remember that balun power ratings are for MATCHED impedances. In most cases, they are not working at matched impedances and thus must be de-rated for power handling.

73
Bob, K4TAX




----- Original Message ----- From: "denton sprague" <denton@oregontrail.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Saturday, July 27, 2013 9:59 AM
Subject: [TenTec] which balun?


Thought would start a little poll..
Which balun are you using with your 238 series TT tuners and multi band antenna? Currently, I use a balun designs 4214t 4:1 balun to feed my 80 meter horizontal loop…with 450 ohm feeders.
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