Bob Henderson wrote:
> Well...........the one thing that everyone appears to be overlooking here is
> PBT. If the 2400 Hz roofing filter were to switch in at 2400 Hz DSP then
> the PBT control would not function. Instead of adjusting the position of
> the passband relative to carrier it would merely be effective as a b/w
> reduction control and Orion already has one of those.
Not true.
It is easy to verify that PBT functions correctly
with both filters at 2400 Hz, or any other value.
> I imagine Ten Tec have used DSP b/w = 75% roof b/w to maintain a reasonable
> PBT range at all DSP bandwidths.
No, Orion normally uses only the central part of roofing filter's BW
in order to prevent deterioration of DSP filter's flatness in the passband.
73,
Sinisa YT1NT, VA3TTN
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|