NI0C wrote:
>For the (roofing filter/221) combo: the lower cutoff is ~462 Hz
and the upper cutoff is ~640 Hz , resulting in a bandwidth of 178 Hz
and a (geometric mean) center frequency of 544 Hz.
>substituting the Inrad 753 for the Ten Tec 221 gives a center
frequency of 620 Hz and a bandwidth of 370 Hz in combination
with the CW roofing filter.
By contrast this illustrates the advantage of Orion's
very flexible control architecture. I can select ANY CW
Pitch offset from 200-1000 Hz in 10 Hz steps, and ALL
filters (both roofing and DSP) are automatically centered
on that Pitch, independent of what bandwidth is selected
for either the roofing filter or DSP filters.
After seeing your analysis above, if I had an Omni, I
would be looking for a different center frequency filter
than the 700 Hz Inrad chose. Do many people really use
700 Hz pitch? Speaking as a low-band weak-signal guy, I
really find that hard to believe. I get nosebleed at >450
Hz which I use only for contests. The TS-930S was the
most flexible rig in this respect until Orion. Even the
FT-1000MP would center all IF filters on the desired pitch
(300-1000 in 50 Hz steps I recall). What I don't understand
is why Ten-Tec did not adjust the IF frequencies for the
Omni as they do in Orion to correct for different Pitch
settings. Seems like they could have done that since the
rig is both synthesized and under uP control?
73, Bill W4ZV
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