> My Omni VI has the RTTY filter installed. Is it "normal" to have to adjust
> the PBT control to approx 2:30 to properly receive rtty?
When an Omni VI has the VCXO adjustments, C24 and R18, on the 6.3 MHz IF
/ PASS BAND TUNING BOARD adjusted properly, the PBT adjustment range is
4 kHz total, or +/- 2 kHz. In CW, LSB or FSK modes (all of these use the
same receive BFO frequency) IF signals which produce audio outputs
centered around 800 or 1000 Hz will be passed when the PBT knob is
centered (12 o'clock). The PBT knob needs to go counterclockwise (or
anticlockwise if you're in the UK) for for lower tones and clockwise for
higher tones. With a FSK filter in the 9 MHz IF, the signals that pass
through that filter produce higher audio tones, and when using a narrow
filter in the 6.3 MHz IF, it is necessary to turn the PBT knob clockwise
from center in order to get the 6.3 MHz IF passband coincident with the
9 MHz IF passband.
The short answer to your question is: Yes.
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