Firmware-only Suggestions:
- RTTY Mark Display Frequency - Just as CW displays the carrier frequency of the received CW signal, the RTTY mode ought to display the frequency of the Mark signal. A menu option would be needed to set the frequency of the Mark signal. (This would essentially subtract or add the Mark frequency from the LSB / USB carrier frequency, respectively)
- VOX Toggle - I'd rather toggle VOX on and off, and have the VOX delay time set in a menu. Having to cycle through all the VOX delay times to turn VOX on and off is a real pain.
- Tuning Rates should follow mode - 10 Hz tuning is fine for CW and RTTY, but too slow for SSB. 50 Hz tuning is fine for SSB. The rate button could then be used to switch to 1 kHz step and back to 10 or 50 Hz. It would save a lot of button presses trying to get the right tuning rate. You could also display all the digits of the frequency regardless of tuning step (in which case SSB would alternate the bottom digit between 0 and 5)
- RIT / XIT Display - momentarily display the RIT or XIT offset on the main display when it is changed (much like for power or keyer speed).
- Unified Filter - Rather than having to separately select XFIL and AFIL settings, I'd rather have three of four filter presets that allow me to combine an XFIL and AFIL setting for each mode. One button (say XFIL) would then cycle through the presets. That way, you're always selecting an optimized filter solution, rather than selecting it manually, which is made more difficult because there is no filter display indicator.
- IF Shift - This very handy feature could be implemented with a firmware change. Biggest problem is how to control it. I find the XIT to be useless, so I would vote to replace XIT with IF Shift. An alternate would be to use the Keyer Speed knob in SSB or RTTY modes.
- CW Tuning Direction - an option to flip sidebands on 15m and above, so that the tuning direction stays the same. (This won't work on RTTY or SSB, of course)
- CW Memory Command - have a computer command to write to the CW memories. That way you can program them from the computer and use them from the front panel.
- INP mode for CW PTT - This mode would allow PTT on the dot line and CW keying on the dash line - great for contesting work. (this would disable auto-detect of hand keying)
- Variable Rate Turning - normal tuning is one step at a time, but if you turn the knob faster, the tuning rate increases for as long as you tune quickly.
- Auto-Tuner Out -- Allow one-touch selection of Tuner AUTO/CAL. This would allow one to easily switch the tuner on and off.
Hardware Improvements:
- Improved KSB2 module -- starting with a filter with sharper skirts (better than 1.5 shape factor), 6-10 dB more mic gain available, more positive VOX (using separate VOX amplifier), anti-VOX circuitry.
- Improved KNB2 module -- allow selection of longer blanking times, more thresholds, better blanking action.
- PFx Module -- a tiny little module that has four (or so) buttons. Hooks into the aux line and offers access to eight functions of the K2 (four on tap, four on hold). Obviates the need for FPLY, opens the K2 up for easier access to things like switching filter presets, noise reduction modes, RIT clear. Lots of simpler and cheaper than the KRC2, because it is just the buttons. (This might also be useful for the K3)
- Remote Tuning Knob -- borrow the idea from Ten-Tec. Perhaps part of the PFx module.
- Opto-encoder for RIT/XIT knob -- Replace the potentiometer with a optical encoder. That way, we wouldn't have to manually re-center it.
I intend to keep using my K2 for several years. It's my hope that Elecraft will be able to deliver some of these enhancements.