I checked the mic which has a 4 pin connector and it was not wired for the correct pinout. Rewired the mic. While I had it apart I noticed it was an electret mic and didn't know if the PC122 takes a dynamic or electret mic. Tried the rewired electret and still no audio or modulation.
After reading that the PC122 takes a dynamic mic, i temporarily rewired my 5 pin Cobra dynamic mic to the PC122 pinout using the electret mic cut apart as an interface, and then it worked beautifully.
Still 6.5 watts AM but now getting good modulation.
And getting somewhere between 15 and 20 watts on SSB.
Getting 60-80% modulation with speech.
Whew! what a simple solution in the end; I guess the seller just threw a random 4 pin mic with this radio when he sold it, as they obviously were using a different mic before selling it.
Thanks so very much for the help everyone; I've learned several good lessons here and gotten my introduction to poking around inside radios!
Now that it works I guess I'll have to find some other excuse to keep heading out to the garage..
