[TenTec] Omni VI low signal on recieve

[Dr. Gerald N. Johnson]

On Fri, 2006-09-08 at 10:28 -0400, Harry N. Coates wrote:
> Mark,
> I had a similar occurrence when I installed the Inrad roofing filter mod.. When I turned the Omni on, after completing the mod there was very little signal.. What had I done to my radio now?? 
> 
> Ended up being a poor grounding connection on the BPF/FRONT END board.. Bottom left hand front board.. Gave each mounting screw a tweak and all was well.. Seemed like only one screw was the real grounding connection.. After finding that, I went through the whole radio nudging every mounting screw I could find.. Never had seen an S9+20 signal before on this Omni, and there was a marked noise reduction..  FWIW.. 
> 
> GL,
> Harry N. Coates
> Comstock Park, MI
> WA8HC at charter.net

I've fixed many radios by tightening the board ground screws. The board
material relaxes under pressure and takes the pressure of the contact.
TS-120 and 130 go into transmitter oscillations on the higher bands when
certain ground screws get loose. Other radios get noisy, made worse by
vibration as in a mobile or hand held radio. Sometimes it helps to use a
star or shakeproof lock washer between the PC board and the chassis to
lengthen the time between screw tightening. It would be a more reliable
design to solder braid to the ground bus on the PC board and ground it
with a crimp lug held to the chassis with a brass screw and shakeproof
lock washer. It would be a pain to do that multiple times per board so
that's probably why its not commonly done.
-- 
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer