开云体育

Hi Jerry,
thanks for asking. Yes some extra explanation may be necessary.

It is assumed that the user has already calibrated the VFO frequency both
in LSB and USB mode.
So if we tune to a carrier so that we receive it exactly zero beat, it
should remain exactly zero beat when flipping between LSB/USB mode.

Suppose the user's preference is a CW pitch of 800Hz. To hear a 800Hz tone
in LSB mode, he will need to tune up by 800Hz. But the TX frequency must
remain the same. I've written the code so that in CWL (LSB) mode, the TX
frequency is always 800Hz lower than the dial frequency.
In CWU (USB) mode the TX frequency is 800Hz higher than the dial frequency.

The amount of offset is also aligned with the sidetone pitch. So if the
user prefers a pitch of 700 Hz, then both the sidetone as well as the
frequency shift will be 700Hz. The desired pitch can be set in the
SETTINGS menu.

Hope it's more clear now.

73, Allard PE1NWL