Re: [Elecraft] [K2] PLL Reference Oscillator Question
Hello Don, Hope you had a good New Year's. I replaced X1 and subsequently D16 and D17, with no luck, still reading 12650. Getting a little frustrated. Any suggestions? 73, Byron N6UI bviets wrote: > > Don, > Well everything checked out, i can't find any fault with the installation > of those components. Looks like I need to order some parts, unless you > can think of anything else I should check. If I haven't mentioned it, > thank you for all of your help and attention. > 73, > Byron > N6UI > > > > Don Wilhelm-4 wrote: >> >> Byron, >> >> Fine on all that, so far so good - next is to check L31, X1, R21, D18, >> C84 and C85 for good soldering, and make certain D16 and D17 are >> oriented correctly. >> If nothing is found awry, I would arbitrarily replace X1 as the first >> step and after than D16 and D17. Remember that this is just like a VXO >> circuit, no real 'magic', you add capacitance (that is what the >> varactors should be doing at lower voltages) and the frequency shifts >> downward. >> >> 73, >> Don W3FPR >> >> bviets wrote: >>> Don, >>> I also took the liberty to do the checks on: RP2 pin 2, and the cathodes >>> on >>> D16 and D17 and they all behaved like U6 pin 1: 7.4 and zero when >>> switching >>> between BAND+ and BAND-. >>> 73, >>> Byron >>> N6UI >>> >>> >> __ >> 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 >> >> > > -- View this message in context: http://n2.nabble.com/PLL-Reference-Oscillator-Question-tp4219007p4248126.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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] [K2] PLL Reference Oscillator Question
Don, Well everything checked out, i can't find any fault with the installation of those components. Looks like I need to order some parts, unless you can think of anything else I should check. If I haven't mentioned it, thank you for all of your help and attention. 73, Byron N6UI Don Wilhelm-4 wrote: > > Byron, > > Fine on all that, so far so good - next is to check L31, X1, R21, D18, > C84 and C85 for good soldering, and make certain D16 and D17 are > oriented correctly. > If nothing is found awry, I would arbitrarily replace X1 as the first > step and after than D16 and D17. Remember that this is just like a VXO > circuit, no real 'magic', you add capacitance (that is what the > varactors should be doing at lower voltages) and the frequency shifts > downward. > > 73, > Don W3FPR > > bviets wrote: >> Don, >> I also took the liberty to do the checks on: RP2 pin 2, and the cathodes >> on >> D16 and D17 and they all behaved like U6 pin 1: 7.4 and zero when >> switching >> between BAND+ and BAND-. >> 73, >> Byron >> N6UI >> >> > __ > 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 > > -- View this message in context: http://n2.nabble.com/PLL-Reference-Oscillator-Question-tp4219007p4222459.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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] [K2] PLL Reference Oscillator Question
Don, I also took the liberty to do the checks on: RP2 pin 2, and the cathodes on D16 and D17 and they all behaved like U6 pin 1: 7.4 and zero when switching between BAND+ and BAND-. 73, Byron N6UI bviets wrote: > > 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
Re: [Elecraft] [K2] PLL Reference Oscillator Question
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:Elecraft@mailman.qth.net >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net
Re: [Elecraft] PLL Reference Oscillator Question
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:Elecraft@mailman.qth.net > > 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-tp4219007p4219481.html Sent from the Elecraft 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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
