[Elecraft] Semi OT: ratios of unun windings

[mike]

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Good evening, all.  I'm in the process of beginning to experiment with a 
wanna-be Beverage, and had a question about winding an unun for 
it.  Through the ARRL Handbook & Amidon's literature, I've calculated the 
number of primary & secondary turns needed for the chosen core.  BTW, the 
antenna is for LF, receive only.

I've come up with a ratio of 18:54 turns (50 ohms:500 ohms).  Is it 
permissible to reduce this to 9:28, or even 3:9?  As in, I assume the magic 
isn't in the exact number of turns, but rather the ratio between primary & 
secondary windings.  Although 1:3 would be the next step, I get the feeling 
that this would not allow for adequate coupling between the 
windings.  Working the formulas backwards, the 3:9 actually turns out to be 
a 50 ohm:450 ohm match, which is still adequate for my testing (since the 
impedance of the antenna at LF is only an estimation anyway, and is only 
for receiving).

Does all this make sense?

73,

Mike Boice, KW1ND
Nampa, Idaho

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