You could let the signal jump around in the 45mhz filter like that,?
should work ok but USB won't sound quite like LSB.
That's exactly the problem that was complained about in this thread:
? ??
/g/BITX20/message/44278The code presented in that post keeps the signal of interest centered in both filters
for both USB and LSB.
Regarding my scheme to plot curves for the crystal filters:
You may have to assert CW_KEY to get enough energy from CLK2 to make it through the 45mhz filter.
Could turn on CLK0 (the BFO) and monitor the audio instead of implementing an RF detector.
Jerry, KE7ER
On Wed, Feb 23, 2022 at 04:12 PM, Ron Carr wrote:
Shouldn't the OSC2 frequency be different for USB and LSB modes, so that the spectrum in the 1st IF is always centered in the passband?
You could do that but it would be needlessly complicated due to how wide the 45mhz filter is.? If the suppressed carrier of signals received is set in the middle of the passband, you receive LSB off to one side of center and USB off to the other side.?? And so you end up using 6 khz of the filter.
