[TenTec] Oll & RF @mic input.

Carter k8vt at ameritech.net
Tue Jan 31 14:36:07 PST 2012

On 1/31/2012 5:06 PM, Stuart Rohre wrote:
>  Try coiling up part of a mike cable into an orderly solenoid coil,
>  NOT scramble wound. You can put it on a pop bottle or other pipe
>  form for a test. If that works, you can measure and compute what
>  inductance it was and replicate it with a ferrite core, passing the
>  mike cable thru and around that for fewer turns.
>  If you want to get deep into the radio, see if there are ferrite
>  beads on the mike connector wiring, and if not, add that. Beads web
>  sites usually have application notes on how much equivalent
>  inductance you get per bead and you can put multiple beads if there
>  is room. Insulate the beads from contact with chassis or other
>  conductors.

This may or may not be the time/place to bring this up, but here goes 

I've got an Omni VI Option 3 and could never run more than ~ 15 watts 
without RF getting in to the transmit audio. Tried the above with a 
ferrite core and no luck. After years of avoiding SSB, there was finally 
talk here on the reflector about the cause of the problem, ultimately 
named the "pin 1" problem. (Had something  to do with pin 1 on the mic 
connector and a floating ground or some such between the connector and 
the PC board).

I called TT tech support and they sent me a sheet with the suggested 
fix. However, being a CW and digital op, I never worked on the problem.

Several years later, when I had need to get on SSB, I could not find the 
sheet TT sent to me. When I called them to get a new sheet, they 
disavowed any and all knowledge of the issue.

So, what is happening here? Am I totally hallucinating? Am I missing 
something? Does anyone here on the reflector remember the "pin 1" 
thread? BTW, TT says too much RF in the shack -- but I've had other 
solid state rigs (Drake TR-7) work fine; also, because of the physical 
layout of the house/property/trees and zoning and subdivision 
restrictions, I am not able to re-locate my antenna as suggested by TT. 
Any fixes -- or is this just an inherent issue with the Omni VI?

Any thoughts or comments appreciated...

Carter   K8VT

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