[Elecraft] Feature Add for P3 -- DX Split Mode

[Bob]

I wonder if it might be possible to add a DX Split Mode to the P3 (beyond
the fixed or tracking mode)?

I would envision this to maintain the current RX frequency close to the
left or right side of the screen (depending on split UP or DOWN).  The RX
frequency would be shown in green above the RX spot, and the TX frequency
would be shown in red on top line of the opposite side of the screen.  The
TX frequency would move along the display -- using the right or left arrow
indicators if it is beyond the display limit.

Should the user change the RX frequency, then the display would shift, but
the RX frequency would continue to stay in the same spot near the right or
left side of the screen.

The span could be adjusted at any time, but it would not cause the RX
frequency display to shift from its position on the screen -- it would
allow for larger or narrower display of responding signals.  The span tick
marks would be scaled to the span but still be something logical so it
would be somewhat easy to figure out +1 +2, +5, +10 splits.

The traditional center frequency display would be removed.

Perhaps the FixTrack could be changed to be
Fixed/Tracking/SplitUp/SplitDown and you could step through the modes that
way.

Anyway, this is sort of how I run things today but I have to keep moving
the span and reference frequency when I change things -- changing the span
causes me to to back to square one.

73, Bob, WB4SON