I'm kicking around a CW "auto tuner" idea... Your input...
Ok, I recently built a CAT interface cable and am developing my own software to control my Kenwood TS-450S and had a fun idea pop up...
While in the middle of coding the project I thought it would be very cool to build a CW "zero" function where the incoming CW audio would be compared against my radio's 700Hz side tone and I would be able to tune visually to center up the other station transmit frequency.
My idea was to tap into the radio's audio, use a LPF to create a logic "1" every time the other station is transmitting a dit or dah and then feed both the audio and logic into a PLL of some sort. The PLL will have a 700Hz reference and will output a voltage corresponding to how far off in frequency I am.
As far as the output. I want to build a 10 bar LCD indicator as well as somehow port the reference voltage into my computer to have my CAT interface auto-tune to center up on frequency.
So, what do you think?
Next question... Any idea what would be a good PLL chip for this activity? How about generating a 700Hz reference tone?
I would like something fairly accurate but also want to spend as little as possible.
Finally, do you know of any free spice simulators? I have SwCAD III but wondered if there was anything else out there.
Thank you for your input!