[Boatanchors] antenna question
gzook at yahoo.com
Thu Jan 16 15:43:25 EST 2014
The entire driven element.
My 2-meter yagi started out as a Cush-Craft and the gamma match got into very poor condition. I replaced the driven element with a folded dipole with the 2:1 rod diameter ratio. My 222 MHz yagi still has the original gamma match. Basically, the type of match used on the driven element really doesn't matter.
I obtained my 6-meter beam, along with other things, and there was no indication of the manufacturer. It resembled the Cush-Craft but there were a few things different. The driven element was in very poor condition and the gamma match was in even worse condition.
On Thursday, January 16, 2014 12:43 PM, Jack Taylor <jack at n7oo.com> wrote:
Glen, which horizontal element are you referring to, the gamma rod or the
Jack - n7oo
From: RAY FRIESS
Sent: Thursday, January 16, 2014 11:15 AM
To: Glen Zook ; BoatAnchors
Subject: Re: [Boatanchors] antenna question
Actually, I misspoke... My two meter antenna is the Cushcraft just like
yours. Two 11 element phased. I have them
vertically mounted and phased for FM. It's the driven elements on them that
are gamma matched and kind of in
crummy shape. I thought instead of rebuilding the gamma matches, I'd just
build a different kind of driven element
that can be attached to the boom, or a type that I can insulate from the
boom with a small plastic block mounted to the boom itself.
Date: Thu, 16 Jan 2014 10:03:54 -0800
From: gzook at yahoo.com
Subject: Re: antenna question
To: rayfrijr at msn.com; boatanchors at puck.nether.net
Generally, the type of match on the driven element doesn't matter.
On both my 6-meter yagi and 2-meter yagi, I have changed the driven element
to a folded dipole. This was done because I was having problems with the
gamma match on both antennas.
If you make one of the horizontal sections half the diameter of the other,
the impedance will be close to 200-ohms instead of the 300-ohms when both
sections are the same diameter. Then, matching to 50-ohm coaxial cable only
requires a simple coaxial cable balun.
My 6-meter yagi and my 2-meter yagi can be seen in the second photo at:
http://k9sth.com/uploads/Antennas_At_K9STH.pdf Glen, K9STH
On Thursday, January 16, 2014 11:03 AM, RAY FRIESS <rayfrijr at msn.com>
First of all ... let me take a moment to express sadness at the loss of
Glen's fellow author, Glen W6ISQ. While he was not a "technical" author
like Glen, it was always a real joy to read his stuff, just like it was to
read Glen's stuff in the magazines.Now .. I have an antenna technical
question.I have a HyGain 11 element two meter beam that uses gamma matching.
The question I have is, does the type of drivenelement matter on a given
beam as long as the driven element is adjusted for the best match at a given
frequency?In other words, I am refurbishing the beam and have given some
thought to redoing the driven element and usinga dipole, folded dipole or
hairpin, or a Y match driven element.Ray WA7ITZ
Boatanchors mailing list
Boatanchors at puck.nether.net
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2012.0.2247 / Virus Database: 3681/6508 - Release Date: 01/16/14
More information about the Boatanchors