it becomes.
- Original Message -
From: Ralph Parker ve...@dccnet.com
To: topband@contesting.com
Sent: Thursday, December 18, 2014 7:59 PM
Subject: Topband: Shunt Feed - Insulated Elements on Yagi
Good question, Stan. I've wondered the same thing.
I have a 64' self-standing tower with a 3
I have never had an issue with this on any tower I have shunt fed that had
a Yagi at the top with insulated elements, but then again my insulators are
probably a lot better than the average ones used on commerical antennas. I
am thinking about shunt feeding a tower that is not mine and wanted to
Stan - For about 8 years, up until this past spring, my shunt fed tower
for 160 had a KT34XA (insulated elements, later upgraded to a KT36XA same
insulated elements) at the top and I never experienced any issue at all
running 1500 watts, even during a few contests where, as you know, you are
One of the factors for arc over is the diameter of the tower and
top support pipe diameter length.
A really FAT 1/4 wave tower may have 1000 ohms at the top, while a
skinny tower would have much more.
The higher the impedance, the higher the voltage to cause arc overs.
73
Bruce-K1FZ
Understanding what Bruce has posted would support the theory that a cage
feed tower is indeed fatter with a lower impedance and thus less
proclivity to arc over on the insulated elements.
Herb Schoenbohm, KV4FZ
On 12/18/2014 12:33 PM, k...@myfairpoint.net wrote:
One of the factors for arc
Concerning voltage breakdowns using yagi-loaded towers on 160 meters... I
have heard stories of arcing to beat the band, that included a fair amount
of destruction. I have heard stories of nothing needed for good operation,
even at QRO. All these stories have to exist in the same logical space.
On Thu,12/18/2014 4:59 PM, Ralph Parker wrote:
I have a 64' self-standing tower with a 3 el Steppir on it (insulated
elements) and a 40m linear loaded dipole (also insulated) on top of that.
I've worried that any high voltage on the ends of the boom might be harmful
to the drive motors in the
