That would work as well. I used something similar, but with less turns to
precede the 4:1 current balun feeding the drivers on my home brew 5-band
quad.
Charlie, K4OTV
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Jim
Bennett
Sent: Thursday, October 24, 2013 7:41 PM
To: Gary@ka1j.com
Cc: topband@contesting.com
Subject: Re: Topband: Balun question
I was just looking through the ARRL Antenna Book - if it's RG-8, then 8
turns would work if wound on an 8 inch PVC tube. However, that size PVC may
be difficult to find, and certainly wouldn't be to spiffy hung way up the
air. But then again, you were thinking about 10 turns on a 12 inch diameter
form...? I assume you were going to place it at the apex of the Inverted
Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch
OD and pass the coax through it six times. That ought to get about 5,000 ohm
impedance at 3.5 MHz and would do the trick. I'm using exactly that on my 80
meter Inverted L and it does a fine job. Mouser has those cores for $6-$7
each.
Jim / W6JHB
On Thursday, Oct 24, 2013, at Thursday, 4:25 PM, Gary Smith wrote:
> Though this reflector is for 160M I have an 80M question that might be
> best asked here. My father W1BML is on an 80 meter net nightly.
> His antenna in an inv-V with 40 & 80 elements though he never uses 40
> any more. I needed to fell a couple of trees to remove branches that
> were touching his copperweld and the W2AU balun he had broke in two
> during the process. (Don't ask, your imagination is probably correct)
> :) And he would like it put back the way it was, with a balun. He's
> 96 so I try to keep him happy.
>
> I'm thinking 10 or so rolls of coax around 1' in diameter ought to be
> fine for a choke on 80. Any better suggestions?
>
> Thanks,
>
> Gary
> KA1J
> _________________
> Topband Reflector
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