[TenTec] PBT function in Omni V, Omni VI and others

[Ken Brown <ken.d.brown@hawaiiantel.net>]

> If the 6.3 filter is narrower than the 9 MHz filter then it
(the 6.3 MHz IF filter)


>  will set the
> receiver bandpass and one that is moved over the spectrum passed by the
> 9 MHz filter until it gets to the edges. 
While the 6.3 MHz IF bandpass is completely within the 9 MHz bandpass, 
the 6.3 MHz filter will set the bandwidth, and the PBT adjustment will 
shift the position of the bandpass. This should be apparent when 
listening to wide band noise or modulation. The "tone" of the audio will 
shift as the PBT is moved.
As the PBT is moved so far that the whole 6.3 MHz bandpass is no longer 
within the 9 MHz bandpass, the following begins to happen
> Then depending on the direction
> of offset one filter sets the high side and the other sets the low side.
>
>   
Now the PBT is not only changing the position of the passband, it is 
also changing the bandwidth.
DE N6KB