Ken Wilson wrote:

Would some of you receiver experts that lurk here please explain to me
why the selectable SYNC on the R8B is any differient than using the PBT
while in SYNC on the R8A.

Now a receiver that had a limited PBT range ie.. JRC I can see that it
would not give true USB/LSB shift. But on the R8A the PBT will cover
more than the 3khz bandwith on each side band.

Take 5.070 mhz now at 02:18 utc. There is a a pinging sound on the USB
side but not on the LSB. I engage the SYNC in AM mode 6khz filter & I
hear the ping with the PBT set to 12:00 oclock setting. If I slide it
slowly to the Left or the LSB I do not hear the Ping. If I shift the
PBT to the right or the USB & the ping is there.

Is this not the same as selecting USB or LSB on the R8B SYNC ?????

73, Ken


With PBT, the ability to attenuate the unwanted sideband is limited by the
skirt selectivity characteristics of the filter.

With selectable sideband sync detectors, the unwanted sideband is cancelled
by the circuitry. This can be significant if the detector is well tuned.

The two are not the same.