I have had extremely good luck with the quarter-wave counter-poise. I've
used a multi-conductor cable (similar to rotor cable). I first remove the
insulation from all the conductors of the cable for several inches and
solder them together. The from that end measured off the middle of the band
quarter wave lengths of 80, 40, 20, 15, and 10 meters. I cut the cable at
the 80 meter mark, then open the cable at 40 meter mark, cut one conductor
(i.e. red) and remove its remainder from the un-soldered end. I move down
the cable to the 20 meter mark, cut any conductor except the previously cut
one (red) and repeat on down the cable.
If the problem is caused by high RF voltage on the equipment, a
counter-poise may move the RF high voltage point to the quarter wave point
of the wire. As a result, humans, animals, and sensitive electronic
equipment should be protected from direct and near contact.
73 & DX,
Gary - AB9M
-----Original Message-----
From: Frank Kirschner
Sent: Friday, May 16, 2014 4:02 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Eagle problem?
Have you tried a quarter wave counterpoise or an "artificial ground"? I had
RF into the mic jack, and a quarter wave counterpoise for each band fixed
it. Later, I put in an artificial ground (the shack was on the second floor
of the house), which required retuning for each band, but I had no RF
problems after that. All the rigs (TS-440, TS-480. Omni V) had the same
problem, and both of the fixes worked on all the rigs.
73,
Frank
KF6E
----- Original Message -----
From: Carter
Sent: 05/14/14 04:35 PM
To: tentec@contesting.com
Subject: Re: [TenTec] Eagle problem?
On 5/8/2014 6:51 PM, Stuart Rohre wrote: An interesting thought, but can we
always blame the "antenna being too close to the shack"? I bought my Omni VI
new in 1994 and have never been able to operate SSB or PSK31, SSTV or any
other mode that required the use of the mic jack. (Good thing I am 99% a CW
and RTTY guy. <grin> ) Anything over about 10 (ten) watts of power seems to
cause the problem, utter and complete distortion of the radiated signal. The
shack is in the basement, the antenna is a 132' long dipole about 25 feet
high and fed with ladder (window) line to a Johnson KW Matchbox tuner. The
length of the window line between the Matchbox and the hole in the wall
where it exits the basement is no more than five feet. Yes, when I measure
the RF current in each leg of the window line they are different -- to be
expected as this is not a perfect world and the dipole is not in free space.
The coax cable to the Centurion / Omni VI has a multiple ferrite bead balun.
After year
s of unsuccessfully chasing around with ferrite beads and chokes, I was
finally told [by ******] that my dipole was "too close to the house".
Unfortunately, because of the shape of the lot, the location of trees and
zoning/deed restrictions, the antenna HAS to be where it is. So...problem
occurs at around 10 watts of output, the antenna can't be moved and I don't
think I am the only ham in the world using a dipole close to the house fed
with window line. This leads me to do the unthinkable and to ask about the
elephant in the room. Rather than everyone saying the antenna "is too close
to the house", is it possible that this particular vintage of Omni VI option
3 is just particularly sensitive to RF getting into the mic jack (or other
ports)??? Is this unique to my radio? Do Yaecomwoods suffer from the same
issue? The reason I ask is that I am getting into PSK31, JT9 and JT65-HF
(and yes, I realize these are "low power" modes), but I wouldn't mind going
up to 20 or 25 watts -
- or SSTV at (gasp!)100 watts. I would appreciate any thoughts or
suggestions. New /different radio or fixing this radio (how?) is OK, but a
100' tower 300' away is just not an option. 73, Carter K8VT
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