Figure 20 Carrier Frequency And Crystal Filter Relationship - ozQRP MST3 Construction And Operation Manual

This diagram shows the carrier
frequency correctly aligned with
the crystal filter passband. The
whole of the LSB is passed but the
USB is filtered out.
In this diagram the carrier
frequency is shifted high in
comparison to the crystal filter.
This results in the low audio
frequency components of the LSB
being filtered out. This would make
the signal sound thin and lack body.
In this diagram the carrier
frequency is shifted low in
comparison to the crystal filter.
This results in the high audio
frequency components of the LSB
being filtered out. This would make
the signal sound muffled and have
too much bass.
Note also that some of the USB
signal is passed by the filter.
Figure 19 Carrier frequency and crystal filter relationship
MST3 Construction and Operation Manual – Issue 1 Page 56