"Ordinary" coax could mean anything from hard line to poor shielding
coverage CB or RatShack cable. My apologies to RatShack if they have
improved their offerings in the 10 or so years since I last looked.
Since many hams tend to be cheap their view of ordinary coax would give
excessive leakage from the center conductor and possibly creating all sorts
of non linear problems with the ferrite.
A big reason I get away with almost no family or neighbor complaints (all
complaints have been telephones and have been cleared up) on any frequency
from 1.8 thru 1296 is my use of all 75 Ohm hardline coupled to quad shield
RG-11 for flexible use around rotators and in the shack. A pleasant benefit
is lower loss than comparable 50 Ohm cables.
All feedpoints use ferrite sleeve baluns tailored to the frequency of use.
One size does not fit all applications.
----- Original Message -----
From: "Jim Brown" <email@example.com>
To: "Tower Talk List" <firstname.lastname@example.org>
Sent: Thursday, June 14, 2007 2:14 PM
Subject: Re: [TowerTalk] Balun question
> On Thu, 14 Jun 2007 10:56:40 -0700, David Gilbert wrote:
>>Per your comment below, I'm curious why I don't hear people using small
>>diameter high-flexibility heliax for ferrite core baluns. FSJ1-50 (1/4
>>inch diameter) and FSJ2-50 (3/8 inch diameter) are both rated for a
>>one-time bend radius of 1 inch, and either should handle a lot of
>>power. Short lengths (5 to 50 feet) of both types regularly show up on
>>eBay at well under a buck a foot.
> Probably for the same reason that it isn't in genreal use in ham radio --
> few hams (including me) know about it or know that it is available at low
> cost. I see no reason why it wouldn't be a good choke material. On the
> other hand, ordinary coax works fine too.
> Jim Brown K9YC
> TowerTalk mailing list
TowerTalk mailing list