[Top] [All Lists]

Re: [TowerTalk] Mounting A Solenoid Balun?

To: "W7TMT" <>
Subject: Re: [TowerTalk] Mounting A Solenoid Balun?
From: Bill Coleman <>
Date: Thu, 28 Oct 2004 22:19:57 -0400
List-post: <>

On Sep 29, 2004, at 10:52 PM, W7TMT wrote:

I'm just finishing up refurbishing a 12 year old A3S and
adding the 40 Meter kit that's been languishing in the
basement for a long time. After researching the various
balun options I decided to go with a solenoid style. Using
the excellent data available on the Web by Tom, W8JI and Ed,
WA2SRQ I'm winding 12 turns of RG-213 on a 4 1/2" PVC form.
Unless I'm missing something that should be in the ballpark
for 40 thru 10 meters.

I was doing something like this a few years back. I had refurbished my A3S and was working on a balun. I was going to use 10 turns of RG-213 on a 4" ID PVC form. My plan was to use a U-bolt and fasten the far end of the PVC to the boom. In order to get to the ends of the U-bolts, one end of the PVC was cut at a 45 degree angle, the other cut square.

I thought about the proximity of the boom affecting the coil. A flat plate would act as a shorted turn and reduce the inductance. So, I cut about 16 inches of pipe, to position the coil a couple of diameters away from boom.

In the end, though, I found some #77 ferrite beads cheap that would fit over RG-213. I measured the impedance of one, and used 10 (about 16") of beads.

Bill Coleman, AA4LR, PP-ASEL        Mail:
Quote: "Not within a thousand years will man ever fly!"
            -- Wilbur Wright, 1901


See: for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.

TowerTalk mailing list

<Prev in Thread] Current Thread [Next in Thread>
  • Re: [TowerTalk] Mounting A Solenoid Balun?, Bill Coleman <=