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Re: Topband: Two 2:1 transformers to choose from!!

To: "'topband'" <topband@contesting.com>
Subject: Re: Topband: Two 2:1 transformers to choose from!!
From: "Tom W8JI" <w8ji@w8ji.com>
Reply-to: Tom W8JI <w8ji@w8ji.com>
Date: Thu, 22 Aug 2013 21:40:38 -0400
List-post: <topband@contesting.com">mailto:topband@contesting.com>

Since  you wound both transformers, why not try them both, and see if you
can measure any difference? I' guessing you won't see much!



Unless the antenna system is starved for background noise, or the element is in an end-fire phased array, it makes very little difference. The only real effect of mismatch is signal and noise from the antenna drop equally. Outside of a low sensitivity array, or an array that is phased end-fire, until background drops with 10 dB of RX system noise floor, or preamp noise floor, it really doesn't matter.

Two turns for 75 ohms is plenty for decent 100 kHz to 30 MHz performance.

Now if you hook up a Sky Buddy, it's a different problem.  :)

Tom
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