[R-390] More on my new (old) R-390

[Jim Green]

I got the function switch to work. It was the power micro switch. I  
also got the bandwidth switch to work.

One thing I didn't mention before is my zero adjust clutch doesn't  
seem to be working. I think I know why. I'm pretty sure the knob is  
not the correct one. It looks like the shaft is threaded and the knob  
is a set screw type for 1/4 inch shaft. I don't know what the  
original knob was supposed to be like. Any suggestions would be helpful.

Jim