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Re: Topband: Coax VF

To: "Top Band" <topband@contesting.com>,"Mike(W5UC) & Kathy(K5MWH)" <w5uc@suddenlink.net>
Subject: Re: Topband: Coax VF
From: "EP Swynar" <gswynar@durham.net>
Date: Wed, 28 Mar 2007 12:09:01 -0500
List-post: <mailto:topband@contesting.com>
On 28th March, Mike wrote...

> "...it seems that I read in ON4UN a rather ominous recommendation that
foam dielectric be avoided for use as phasing lines, the reason being that
the VF does not remain constant with time & temperature. He recommended
using only solid dielectric coax for that purpose. I know this isn't what
you wanted to hear, but it may save you a lot of grief down the road.  I
will try to find the exact paragraph in the latest ON4UN book."

*************************

Hi Mike,

Well, that's certainly not anything that *I* particularly wanted to hear at
this end, that's for sure! Hi Hi.

I used foam satellite TV cable ("RG-6") here exclusively late last summer
for all of the phasing lines in my transmitting triangular array --- with
the amount of cable that I required, my deciding upon its use was a
"no-brainer" on account of its price advantage to me (Home Depot Canada
sells 500' spools of the stuff for less than CDN $49.00!).

Please let me know when you might locate that reference in John's
publication --- up until now, about the only warning against the use of such
cable that I was aware of was to NOT coil it too tightly, to guard against
the possibilty of the center conductor "migrating" through the foam, &
contacting the outer shield...

BTW,  I have all of the editions of his book (save for the second to
last)...I even have his earliest stab at literary notoriety, i,e,  "80-Meter
DX'ing", and a wonderful book that is. I believe that particular one was
published by the folks at the old "Ham Radio" magazine...

~73~ Eddy VE3CUI - VE3XZ

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