Hi Don, Many thanks for the quick reply.
So far the readings I get on U3 are as follows: Pin 14 = 0.1V and 0.133V when the encoder is rotated. Pin 15 = 4.12, which varies when the encoder is rotated. Pin 7 = 3.4V with slight variation when the encoder is rotated. So from the above would you say it's safe to assume that U3 has a damaged output on pin 14? Again thanks very much for taking the time to reply. Regards Nidge (G0NIG) IO93dv ----- Original Message ----- From: "Don Wilhelm" <[email protected]> To: "Nigel (Nidge) Smith" <[email protected]> Cc: <[email protected]> Sent: Thursday, April 08, 2010 9:17 PM Subject: Re: [Elecraft] K2 VFO / Encoder Problem > Nidge, > > It is difficult to predice the exact voltage levels that will be present > in digital signals at any particular time. That may be why the U3 > redings may be off from what is listed in the manual. Check by > comparison instead. > Compare the voltage at FP U3 pin 14 with the voltage your meter reads at > pins 7 and 15 - they should be similar. If they are not, then it is > likely that U3 has a damaged output at pin 14. > > Additionally, check to be certain the signal at encoder pin 2 is making > it to CB U6 pin 8 and the signal at encoder pin 3 makes it to CB U6 pin 16 > > 73, > Don W3FPR > > Nigel (Nidge) Smith wrote: >> I have in my possession a K2 that has developed a fault with >> the encoder. >> >> When trying to tune the radio, rotating the encoder results in just >> the last digit displayed flickering back and forth. >> >> At first I thought the Optical encoder had failed and so ordered a >> replacement from Elecraft which arrived yesterday. Today I installed >> the new Encoder only to find that the problem still persists. >> >> I have checked and confirmed there is a 5Volt supply on pin1 of the >> encoder, pins 2 and 3 fluctuate between 5Volt and 0.1Volt when the >> encoder is advanced or retarded. Pin 4 appears to remain at 0.1Volt. >> In the voltage charts at the back of the manual Pin 4 is connected to >> pin 14 of U3, this according to the charts should be about 3.1Volt. >> >> -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.801 / Virus Database: 271.1.1/2797 - Release Date: 04/07/10 19:32:00 ______________________________________________________________ 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
