[TenTec] OMNI V Question

[OTAKEBI at aol.com]

Have an OMNI V.
Had the coax off the rig and was getting an S6 meter reading.
If I go from the 2.4 to the 1.8 SSB filter goes to 0.
On the 2.4 filter if I turn PBT to the right meter drops to 0 if I turn PBT 
 to the left S meter goes to S6.
If I switch from lower side band to upper side band the PBT control causes  
the opposite response.
The S6 noise level is the same on all bands with the coax off the  rig.
SSB signals sound great and I get full output on all bands with antenna  
connected.
PBT seems to work fine on voice signals.
Anyone else have this problem that might make life easy before I dig  in?
This noise is internal to the rig.
It is not coming from outside the box.
Thanks in advance for any help.
Dan/N4VET
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