Mike, Other than the wiring paths for ENC A and ENC B signals through the connectors and to CB U6 pins 8 and 16, there is nothing else for these two signals. However, for the encoder to be read, the /ENC RD signal must be at a low level and that signal is generated from FP U3 pin 14. Look for low going pulses with your scope. If they are not present, FP U3 may be at fault.
73, Don W3FPR Mike-WE0H wrote: > Hi Don, > > Ref K2 #6698: > > I tried a new encoder but it did nothing different than the original > encoder. Tonight I see that ENC-A is only 2v p-p while ENC-B is 5v p-p. > This is measured right on the encoder terminals and on the U6 MCU chip. > I don't see any resistor network pull ups on these lines. Do you think > the MCU could have gotten hurt with the spike on the 14v VCC line that > shorted the one final and that VCC filter cap? I see data on both ENC > lines when I spin the encoder. The Encoder VCC is a solid 5.0vdc. All > other functions work on this radio except anything where I need to turn > the encoder to access something in a menu or change anything. The radio > receives fine on whatever the display freq is and transmits fine on the > same freq on all bands. I just can't change any VFO digit other than the > far right digit, or if I spin the encoder shaft left & right, it will > slowly increase the displayed freq but not go down. > > Mike > WE0H > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
