[TenTec] AM Receiver distortion in Orion II

[Paul Christensen]

>> "I haven't worked any AM yet with my O II, but I've listened a fair bit. 
>> I've not heard any of the distortion spoken of so far. But I'm certain 
>> that the 6 kHz bandwidth limit imposed by th eroofing filter severely 
>> affects the audio quality. There are no frequency components above 3 kHz 
>> hen using AM. Yet, if I listen to the same signal in SSB with the BW set 
>> to 6 kHz, AM sounds better than I've ever heard it."

This makes perfect sense if the 6 kHz 1st IF filter is selected for both AM 
and SSB modes.  In AM, the LO carrier set point is placed in the center of 
the filter's passband, leaving 3 kHz on each side for simultaneous USB and 
LSB detection.  In SSB, the carrier set point should be placed at either end 
of the lower or upper skirt of the 6 kHz filter, depending on USB or LSB 
modes, leaving detection of a full 6 kHz of available passband. 
Accordingly, an AM station detected in either SSB mode with the 6 kHz 
roofing filter should produce 6 kHz of audio passband.

Not owning an O2, I am just guessing as to how the 6 kHz roofing filter 
should operate based on the feedback I'm seeing here.  Can anyone confirm?

Paul, W9AC