[TenTec] OMNI VI 9MHZ filters

[Ken Brown]

> As I recall the PBT is for the 6.3 MHz IF and not the 9 MHz IF.
>   
True, the PBT works in the 6.3 MHz IF. If the signals coming through the 
narrow 9 MHz IF filter are not also passing through the narrow 6.3 MHz 
IF you won't hear them. So the PBT has to be adjusted so the signals get 
through both IFs. Switch to 2.4kHz BW in 6.3 IF, then 1.8kHz, then 500 
Hz, then 250 Hz, each time twiddling PBT for max noise or signal 
strength. You'll understand what is going on after a while.

When you have a narrow filter in your first IF, you have to have the PBT 
adjusted to make the narrow passbands of both IFs coincident with each 
other.

DE N6KB