Don, I did the voltage tests and they both checked out. U6 was at 7.4, so a little under 8, but I would imagine that is within tolerance. 73, Byron N6UI
Don Wilhelm-4 wrote: > > Byron, > > Yes, that prior response may be helpful, but all may not apply to your > case - each one is different. > To be specific for your problem, first monitor the voltage from RF Board > U5 pin 7 while in CAL FCTR mode. When tapping BAND+, the voltage should > go to about 4 volts and tapping BAND- should drop the voltage to near > zero volts. > If that is OK, then move on to U6 pin 1 - tapping BAND+ should produce > about 8 volts and BAND- should produce nearly zero volts. > > Check those conditions first. If those are all OK, then you can move on > to the varactor tests, but if there is a problem with the voltages > above, get back with me for additional tests and actions. > > 73, > Don W3FPR > > bviets wrote: >> Hi Don, >> Thank you for your response. When I try the freq. range test, there is >> no >> freq. change. I searched the reflector and found an earlier email >> response >> authored by yourself with the subject of: K2 PLL range test SN 05233. >> That >> person had a similar issue, so it would seem I can start tracking down >> the >> problem based on your diagnosis in that email. >> 73, >> Byron >> N6UI >> >> >> >> Don Wilhelm-4 wrote: >> >>> Byron, >>> >>> Don't be too concerned about the 4 MHz oscillator calibration at this >>> point in your assembly process. Once you have completed your K2, you >>> can refine the calibration - see the K2 Dial Calibration article on my >>> website www.w3fpr.com for "the rest of the story". >>> >>> Yes, 12650 is higher than the high end of the range should be, but >>> please tell me what the low range is - while in CAL FCTR, tap BAND+ and >>> tell me what the frequency is, then tap BAND- and again tell me what the >>> displayed frequency is. Perhaps I can craft an answer to the possible >>> trouble spots from that information. >>> >>> 73, >>> Don W3FPR >>> >>> Byron Viets wrote: >>> >>>> Hello everyone. I purchased my K2 kit about 4 years ago and as life >>>> would >>>> have it, I rarely have time to work on the beast except during holidays >>>> etc. >>>> More time for amateur radio would sure be nice, but I'm not near >>>> retirement >>>> and for some reason I keep getting pesky bills in the mail. Anyway >>>> here >>>> is >>>> my situation: >>>> >>>> 1) I am at the Alignment and Test, Part II portion and trying to get >>>> through >>>> the 4 MHz Oscillator Calibration section. >>>> 2) When I take a freq. measurement at TP3 for the PLL with the >>>> frequency >>>> probe, I get a reading of ~12650, obviously way too high. >>>> 3) I inspected parts, soldering etc and cannot find a fault. >>>> 4) Decided to do some signal tracing and performed a measurement of the >>>> reference oscillator signal on pin 1 of U4. My reading is .51, instead >>>> of >>>> the expected 0.8-1.8. Vrms. >>>> >>>> So my question is this: >>>> >>>> It seems that the 12650 measurement is so high that it may be an >>>> indicator >>>> that the X1 crystal in the PLL oscillator is defective. However, with >>>> the >>>> low reading on pin 1 of U4 I'm not so sure about the crystal. Could >>>> the >>>> increased frequency reading at TP3, cause the voltage drain on the U4 >>>> or >>>> am >>>> I barking up the wrong tree? >>>> >>>> I've looked through the email archives and haven't found anything quite >>>> similar to my issue. I hate to start pulling stuff apart if the >>>> crystal >>>> is >>>> the issue and would like to hear what others think of the problem. >>>> >>>> >>>> >>> ______________________________________________________________ >>> 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 >>> >>> >>> >> >> >> ------------------------------------------------------------------------ >> >> >> No virus found in this incoming message. >> Checked by AVG - www.avg.com >> Version: 9.0.722 / Virus Database: 270.14.120/2587 - Release Date: >> 12/26/09 03:27:00 >> >> > ______________________________________________________________ > 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 > > -- View this message in context: http://n2.nabble.com/PLL-Reference-Oscillator-Question-tp4219007p4221868.html Sent from the [K2] mailing list archive at Nabble.com. ______________________________________________________________ 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
