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Re: [TowerTalk] Baluns/tutorial/notes.

To: Tower Talk List <towertalk@contesting.com>
Subject: Re: [TowerTalk] Baluns/tutorial/notes.
From: Kevin Normoyle <knormoyle@surfnetusa.com>
Date: Sat, 22 May 2010 13:59:27 -0700
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
This is all great and thanks for taking the time to go thru it yet one 
more time.
Even though I've read the papers, it's great to see the give and take of 
slightly different points of view for really getting a grip on what all 
the key issues are.

So looking at Fair Rite #61, 13 turns on 2.4" o.d core, seems primarily 
resistive above 14Mhz.

Assuming I'm just thinking about the 20M/15M/10M bands, 13 turns of 
RG303 on a double stack of #61 seems to meet the desired goals?

Am I wrong there?

But then, if our measurement capabilities are better for below 14mhz, 
and I can be confident of the inductive reactance I get from #61 at the 
lower frequencies (and knowing whether there are resonances there)...why 
can't the same double stack be good for <14 mhz?

I guess I'm wondering if the justification for "resistive impedance is 
better" is being taken from one frequency range and being applied to all 
frequency ranges...unnecessarily implying #43 (or #31) is better than #61

?? I may just be trying to summarize something that can't be summarized.

Seems like some of the issue is trying to have one thing cover the range 
of 1-30mhz which is too hard. And our inability to measure well, for 
over 10mhz.

I also can't help but think that using more turns of narrower RG303 thru 
a core is better for controlling stray capacitance, therefore creating 
more repeatable results...especially important if I know I can't trust 
the measurements of what I build.
???
-kevin
AD6Z
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