[TenTec] Eagle problem?

[Frank Kirschner]

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 at 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 years 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