Nidge, Thanks for your reply.
Unfortunately I do not know enough about Hamradio Deluxe nor its interface with the K2, but rightly or wrongly I assume that if the radio works properly under computer control, then the MCU (U6) is working as it should during this mode of control. I cannot shake my hunch that something is pulling down to near ground either the ENC A or the ENC B lines (or both) when the MCU is in place. If the encoder is an optical type, then under such a fault condition I would not be too surprised if the voltage on ENC RD also dropped to near ground - which is what you have measured at U3 pin 14. It would be worthwhile to make some resistance measurements between these three lines and ground, with the power off - MCU in place and MCU removed. Not to be overlooked is the possibility that the fault might be mechanical. For instance if a small sliver of solder had worked its way into the MCU's socket, it might create a short when the MCU chip is in place - but "open" when the chip is removed. Good luck. 73, Geoff GM4ESD On Saturday, April 17, 2010, at 11:13 PM, Nidge (Nigel Smith) wrote: > Hi Don and Geoff > > Thanks for the replies both. > > First of all Geoff: I'm afraid I don't have a scope here anymore. I did > remove the MCU > and checked the voltages, and this time on pin 14 of U3 I had the correct > voltage close > to 3.8V, with the MCU inserted it was below 100mV. > The radio, when connected to Hamradio Deluxe works fine under computer > control, both > on receive and transmit. The filters are off but that's because I'm > unable > to fine tune them > as the encoder isn't working. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
