Re: [Elecraft] VCO Alignment on K2 7109
Hello Don, I have checked the values of c60 and 61 from L30, as well as c96, c95, c94, c93, c92 and c88 from U6 and they are all correct. D21 and D22 are both V149SL. I don't know if you remember but while I was working on phase 2 I had an issue with a mix varactor diodes but that was in the crystal area and I swapped out the incorrect varactor. 73, Ed KE7HGA -- View this message in context: http://elecraft.365791.n2.nabble.com/VCO-Alignment-on-K2-7109-tp6441114p6441984.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
Re: [Elecraft] VCO Alignment on K2 7109
Ed, The fact that your voltage on 80 meters goes from 6 volts to something below 2 volts may indicate a problem with varactors D23 through D26 (the group of 4) - check to be certain they are MV209 and that all are correctly oriented and well soldered. Check the orientation and soldering of D21 and D22. Next check the soldering of relays K13, K14 and K15 - make certain you did not miss soldering pin 1. Then check the values of C71 through C75. Schematic for the RF board sheet 1 shows the VFO range select area, and the Relay Table and VCO Table shown on the K2 Schematic Key page may be required to check the operation of the relays for each band and the capacitors used for each band. Since you have 8 volts at R30 on bands other than 80, make certain you do not have any solder bridges between pins of the relays - be certain C72 is the correct 270 pF value (marked 271). You may have to re-do the 80 meter adjustment of L30 and/or T5 if you change anything. Always check the 80 meter band first and then the other bands. 73, Don W3FPR On 6/5/2011 7:43 AM, EMD wrote: Hello Don, I have checked the values of c60 and 61 from L30, as well as c96, c95, c94, c93, c92 and c88 from U6 and they are all correct. D21 and D22 are both V149SL. I don't know if you remember but while I was working on phase 2 I had an issue with a mix varactor diodes but that was in the crystal area and I swapped out the incorrect varactor. 73, Ed KE7HGA -- View this message in context: http://elecraft.365791.n2.nabble.com/VCO-Alignment-on-K2-7109-tp6441114p6441984.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 __ 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
[Elecraft] VCO Alignment on K2 7109
All, I have mad it to page 64. When I check the volts at R30 using my DMM I get 8 volts. I assume that the left side of R30 would be having the front of the radio facing me so the lead I tested was towards adjacent the side panel. It did drop to 7.5v but at that reading the L30 was at what appeared to be it's maximum travel limit toward the top of the can. I searched the reflector and have found that I have 4.0 volts at U6 pin 5. I have 16 turns of red and 4 turns of green wire on T5. When I decrease the frequency from 4000kHz the voltage does drop. Also I bought the toroid's pre wound since my eye sight is not as it used to be. So where should i go from here? 73, Ed KE7HGA -- View this message in context: http://elecraft.365791.n2.nabble.com/VCO-Alignment-on-K2-7109-tp6441114p6441114.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
Re: [Elecraft] VCO Alignment on K2 7109
Ed, You seem to have run out of adjustment range on L30. You will have to change the turns spacing on T5 to produce a voltage at R30 that is within range. Since your R30 voltage is 8 volts, when tuned to 4000 kHz, tune to a lower frequency so that the voltage is something less than 8 volts. Once you have done that, alter the spacing on T5 to reduce the voltage even further - adjust until the voltage is at something like 5.5 volts - then adjust L30 to bring it up to 6.00 volts when tuned to 4000 kHz. Once the R30 voltage is set at 4000 kHz, check the ends of each band to be certain the voltage is within range for all bands. If it is not, you may have a capacitor problem in the VFO Range Select area (ask about that problem specifically). 73, Don W3FPR On 6/4/2011 10:09 PM, EMD wrote: All, I have mad it to page 64. When I check the volts at R30 using my DMM I get 8 volts. I assume that the left side of R30 would be having the front of the radio facing me so the lead I tested was towards adjacent the side panel. It did drop to 7.5v but at that reading the L30 was at what appeared to be it's maximum travel limit toward the top of the can. I searched the reflector and have found that I have 4.0 volts at U6 pin 5. I have 16 turns of red and 4 turns of green wire on T5. When I decrease the frequency from 4000kHz the voltage does drop. __ 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] VCO Alignment on K2 7109
Don, I did as you suggested and now have the voltage set to 6 volts at 4000kHz. I will check each band as well. Thanks for your help! 73, Ed KE7HGA On 6/4/11 10:51 PM, Don Wilhelm-4 [via Elecraft] wrote: Ed, You seem to have run out of adjustment range on L30. You will have to change the turns spacing on T5 to produce a voltage at R30 that is within range. Since your R30 voltage is 8 volts, when tuned to 4000 kHz, tune to a lower frequency so that the voltage is something less than 8 volts. Once you have done that, alter the spacing on T5 to reduce the voltage even further - adjust until the voltage is at something like 5.5 volts - then adjust L30 to bring it up to 6.00 volts when tuned to 4000 kHz. Once the R30 voltage is set at 4000 kHz, check the ends of each band to be certain the voltage is within range for all bands. If it is not, you may have a capacitor problem in the VFO Range Select area (ask about that problem specifically). 73, Don W3FPR On 6/4/2011 10:09 PM, EMD wrote: All, I have mad it to page 64. When I check the volts at R30 using my DMM I get 8 volts. I assume that the left side of R30 would be having the front of the radio facing me so the lead I tested was towards adjacent the side panel. It did drop to 7.5v but at that reading the L30 was at what appeared to be it's maximum travel limit toward the top of the can. I searched the reflector and have found that I have 4.0 volts at U6 pin 5. I have 16 turns of red and 4 turns of green wire on T5. When I decrease the frequency from 4000kHz the voltage does drop. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] /user/SendEmail.jtp?type=nodenode=6441240i=0 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html If you reply to this email, your message will be added to the discussion below: http://elecraft.365791.n2.nabble.com/VCO-Alignment-on-K2-7109-tp6441114p6441240.html To unsubscribe from VCO Alignment on K2 7109, click here http://elecraft.365791.n2.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_codenode=6441114code=ZWR3YXJkZG95bGVAbWFjLmNvbXw2NDQxMTE0fC00NzE3Mzc3Nzg=. -- View this message in context: http://elecraft.365791.n2.nabble.com/VCO-Alignment-on-K2-7109-tp6441114p6441268.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
Re: [Elecraft] VCO Alignment on K2 7109
Don, After setting 80m high freq to 6.0v the low freq 3500kHz measured 1.7V. Everything else measured 8.0v which as you know IS about .5v above the upper limit of the range. I will try to see if I can get some more spacing on the windings on T5 and try again. 73 Ed KE7HGA On 6/4/11 10:51 PM, Don Wilhelm-4 [via Elecraft] wrote: Ed, You seem to have run out of adjustment range on L30. You will have to change the turns spacing on T5 to produce a voltage at R30 that is within range. Since your R30 voltage is 8 volts, when tuned to 4000 kHz, tune to a lower frequency so that the voltage is something less than 8 volts. Once you have done that, alter the spacing on T5 to reduce the voltage even further - adjust until the voltage is at something like 5.5 volts - then adjust L30 to bring it up to 6.00 volts when tuned to 4000 kHz. Once the R30 voltage is set at 4000 kHz, check the ends of each band to be certain the voltage is within range for all bands. If it is not, you may have a capacitor problem in the VFO Range Select area (ask about that problem specifically). 73, Don W3FPR On 6/4/2011 10:09 PM, EMD wrote: All, I have mad it to page 64. When I check the volts at R30 using my DMM I get 8 volts. I assume that the left side of R30 would be having the front of the radio facing me so the lead I tested was towards adjacent the side panel. It did drop to 7.5v but at that reading the L30 was at what appeared to be it's maximum travel limit toward the top of the can. I searched the reflector and have found that I have 4.0 volts at U6 pin 5. I have 16 turns of red and 4 turns of green wire on T5. When I decrease the frequency from 4000kHz the voltage does drop. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] /user/SendEmail.jtp?type=nodenode=6441240i=0 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html If you reply to this email, your message will be added to the discussion below: http://elecraft.365791.n2.nabble.com/VCO-Alignment-on-K2-7109-tp6441114p6441240.html To unsubscribe from VCO Alignment on K2 7109, click here http://elecraft.365791.n2.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_codenode=6441114code=ZWR3YXJkZG95bGVAbWFjLmNvbXw2NDQxMTE0fC00NzE3Mzc3Nzg=. -- View this message in context: http://elecraft.365791.n2.nabble.com/VCO-Alignment-on-K2-7109-tp6441114p6441297.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
Re: [Elecraft] VCO Alignment on K2 7109
Don, My last idea had no effect so it looks like I have a capacitor problem. 73, Ed KE7HGA On 6/4/11 10:51 PM, Don Wilhelm-4 [via Elecraft] wrote: Ed, You seem to have run out of adjustment range on L30. You will have to change the turns spacing on T5 to produce a voltage at R30 that is within range. Since your R30 voltage is 8 volts, when tuned to 4000 kHz, tune to a lower frequency so that the voltage is something less than 8 volts. Once you have done that, alter the spacing on T5 to reduce the voltage even further - adjust until the voltage is at something like 5.5 volts - then adjust L30 to bring it up to 6.00 volts when tuned to 4000 kHz. Once the R30 voltage is set at 4000 kHz, check the ends of each band to be certain the voltage is within range for all bands. If it is not, you may have a capacitor problem in the VFO Range Select area (ask about that problem specifically). 73, Don W3FPR On 6/4/2011 10:09 PM, EMD wrote: All, I have mad it to page 64. When I check the volts at R30 using my DMM I get 8 volts. I assume that the left side of R30 would be having the front of the radio facing me so the lead I tested was towards adjacent the side panel. It did drop to 7.5v but at that reading the L30 was at what appeared to be it's maximum travel limit toward the top of the can. I searched the reflector and have found that I have 4.0 volts at U6 pin 5. I have 16 turns of red and 4 turns of green wire on T5. When I decrease the frequency from 4000kHz the voltage does drop. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] /user/SendEmail.jtp?type=nodenode=6441240i=0 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html If you reply to this email, your message will be added to the discussion below: http://elecraft.365791.n2.nabble.com/VCO-Alignment-on-K2-7109-tp6441114p6441240.html To unsubscribe from VCO Alignment on K2 7109, click here http://elecraft.365791.n2.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_codenode=6441114code=ZWR3YXJkZG95bGVAbWFjLmNvbXw2NDQxMTE0fC00NzE3Mzc3Nzg=. -- View this message in context: http://elecraft.365791.n2.nabble.com/VCO-Alignment-on-K2-7109-tp6441114p6441318.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
[Elecraft] VCO Alignment on K2
Hello, I am to the point in my construction where I align the VCO. Every measurement has been correct to this point. Unfortunately, the lowest voltage I can get on R30 is 6.1 volts. I have checked that L30 and C72 are both correct. It says that T5 is incorrectly wound in the manual. It looks to me that both windings have the proper number of turns. Does anyone have any hints on getting this voltage a little lower? Thanks 73 Jay KA9OKT ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] VCO Alignment on K2
Jay, I assume you are rferring to the voltage measured at the left end of R30 while the K2 is tuned to 4000 kHz - if the voltage does not decrease as you tune lower in the band, then let's start again because you have a greater problem than just a bit too much inductance or capacity. First thing to do is look at the schematic for the RF Board sheet 1 of 4, and identify the components shown in the area labeled VFO Range Selection. Check those components for the proper values, especially be certain the varactors are the correct type (the 1SV149 has a smaller body than the MV209) and oare correctly oriented. Also check varactors D23, D24, D25 and D26). Do count the turns on T5 once again, being certain that you are counting the number of times the wire passes through the center of the core rather than counting around the outside. If the number of turns are correct, spread the turns out (loosen the mounting hardware first) a bit and the voltage should go down - you did spread the turns out over 85% of the core like shown in the manual did you not? Actually, it is usually preferrable to set the voltage when tuned to 4000 kHz a bit higher than 6 volts, in fact, I usually try for about 6.5 volts there as long as all the other band end points are well within the acceptable range. 73, Don W3FPR -Original Message- Hello, I am to the point in my construction where I align the VCO. Every measurement has been correct to this point. Unfortunately, the lowest voltage I can get on R30 is 6.1 volts. I have checked that L30 and C72 are both correct. It says that T5 is incorrectly wound in the manual. It looks to me that both windings have the proper number of turns. Does anyone have any hints on getting this voltage a little lower? Thanks 73 Jay KA9OKT ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] VCO Alignment on K2
Thank you both for your help. I spread the turns on T5 out a little more and now I get 6V for 4000khz. It also decreases as I tune lower frequencies in the 80/75m band. I will continue the alignment process and see how it goes. Thanks again for your help 73 Jay KA9OKT On 10/18/06, Don Wilhelm [EMAIL PROTECTED] wrote: Jay, I assume you are rferring to the voltage measured at the left end of R30 while the K2 is tuned to 4000 kHz - if the voltage does not decrease as you tune lower in the band, then let's start again because you have a greater problem than just a bit too much inductance or capacity. First thing to do is look at the schematic for the RF Board sheet 1 of 4, and identify the components shown in the area labeled VFO Range Selection. Check those components for the proper values, especially be certain the varactors are the correct type (the 1SV149 has a smaller body than the MV209) and oare correctly oriented. Also check varactors D23, D24, D25 and D26). Do count the turns on T5 once again, being certain that you are counting the number of times the wire passes through the center of the core rather than counting around the outside. If the number of turns are correct, spread the turns out (loosen the mounting hardware first) a bit and the voltage should go down - you did spread the turns out over 85% of the core like shown in the manual did you not? Actually, it is usually preferrable to set the voltage when tuned to 4000 kHz a bit higher than 6 volts, in fact, I usually try for about 6.5 volts there as long as all the other band end points are well within the acceptable range. 73, Don W3FPR -Original Message- Hello, I am to the point in my construction where I align the VCO. Every measurement has been correct to this point. Unfortunately, the lowest voltage I can get on R30 is 6.1 volts. I have checked that L30 and C72 are both correct. It says that T5 is incorrectly wound in the manual. It looks to me that both windings have the proper number of turns. Does anyone have any hints on getting this voltage a little lower? Thanks 73 Jay KA9OKT ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] VCO Alignment
Hello. I appreciate the suggestions related to the subject. What I have found as an anomoly is that pin 7 of U4 is at 4.94vdc, as is pin 1 of U5. Both of these pins are clocking (CLK) I/O pins for U4 and U5. A steady 4.94vdc is abnormal. I also looked more carefully at T5. The four green wire turns are situated such that there are four red wire turns on the 2-4 side and seven red wire turns on the 1-3 side. The green and red wires are in the correct holes. I can find no problems with the thermister nor can I find any soldering problems. Any suggestions at this point would be appreciated. The alignment steps up to VCO alignment and the step subsequent all check out perfectly. Thanks. 73, Jim,K4ZMV ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] VCO Alignment
Jim, If you look at those lines with a 'scope and move the VFO dial, you will likely see very short negative going pulses. They are only active when need be, and will show as almost 5 volts with a DMM. Those lines are likely not your problem unless you missed a solder connection on the signal lines on the control board. Go back a step to verify things: Did you get a successful range when you did the PLL Reference Oscillator test? The high frequency should be near 12100 kHz and the low should be between 12080 and 12090. If that range test was not successful, then you need to start there to find out why. If the PLL range was correct, then proceed to investigate the VCO. The first step is to check the voltage at pin 5 of U2 - if it is anything other than 4 volts (within 10%), stop and recheck the thermistor board. Next step is to find out what frequency the VCO is actually oscillating at for each band. The counter probe should be in TP1 - set the VFO dial to the low frequency end of each band in turn and enter the menu to check CAL FCTR. Compare the frequencies observed with the chart on the lower left corner of the K2 Schematic Key page in Appendix B of the manual. Do the frequency measurements before drawing any conclusions - are all bands incorrect, or only some? If all, what are the frequencies? If some, which ones and what are the frequencies for each? There could be an incorrect capacitor, unsoldered connection, or incorrectly oriented varactor in the VFO Range Select area that would give you the inability to change the voltage at the left end of R30. The absolute limits of the voltage at the left end of R30 (output of U6 pin 7) are 8 volts and zero volts. Your indication that you find only 8 volts says that the VCO frequency is too low and the PLL chip is attempting to reduce the varactor capacity, but has 'run out of adjustment' at the high voltage end. You will have to search for the reason why. I have written a lot of words here, but follow the steps in order - if you find one in th emiddle that is not correct, stop because that has to be corrected before any of the following are attempted (you can expect only 'wierd' readings beyond that point). 73, Don W3FPR -Original Message- I appreciate the suggestions related to the subject. What I have found as an anomoly is that pin 7 of U4 is at 4.94vdc, as is pin 1 of U5. Both of these pins are clocking (CLK) I/O pins for U4 and U5. A steady 4.94vdc is abnormal. I also looked more carefully at T5. The four green wire turns are situated such that there are four red wire turns on the 2-4 side and seven red wire turns on the 1-3 side. The green and red wires are in the correct holes. I can find no problems with the thermister nor can I find any soldering problems. Any suggestions at this point would be appreciated. The alignment steps up to VCO alignment and the step subsequent all check out perfectly. Thanks. 73, Jim,K4ZMV ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] VCO Alignment
Hello. I am building K2 #5731 and I have run into two problems. The first, and most serious, is in VCO alignment. When moving L30, the voltage at the left end of R30 does not change from 8.03vdc. I have been through the entire range of L30, very carefully, with no change. I pulled out T5 and rewound it. It is as nearly perfect as I can get it. When I measure vdc on T5, I see approximately 0.01vdc on 1 and 2 and 2.65 on 3 and 4. I checked voltages on U4 and U6 and they are in the range of the table in the back of the manual. I've checked all the components installed and the soldering. This is my second K2 and I have been a lot more careful. I'm stumped. Anybody got any ideas. The second thing is that parts of the mode indicator on the display have become intermittent. Any ideas on that? Thanks. Jim, K4ZMV ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] VCO Alignment
Thanks, Don. Found the intermittent display problem. And, it was a solder problem. I checked the thermistor and all checks OK there. I'll keep looking ... think I have ruled out the misplaced or misused component option. I'll just go through all the RF board installation steps and check each one. All the other test results are perfect. Got to be something in the synthesizer circuits I have goofed up. Just gotta find it. Thanks again. 73, Jim, K4ZMV - Original Message - From: Don Wilhelm [EMAIL PROTECTED] To: Jim Brassell [EMAIL PROTECTED]; elecraft@mailman.qth.net Sent: Sunday, September 24, 2006 9:34 PM Subject: RE: [Elecraft] VCO Alignment Jim, The most common source of problems with the PLL or VCO is a solder bridge on the thermistor board. There are other possible sources, but check there first. You can often get to the back of the thermistor board by removing the front panel and the control board. You intermittent display is most likely an unsoldered connection (or poorly soldered) - usually on the front panel itself. So check the soldering first, then re-check the soldering, and when that is done, check the soldering - that is the most common failure and misplaced components runs in second place. Bad components are way down the list. 73, Don W3FPR -Original Message- I am building K2 #5731 and I have run into two problems. The first, and most serious, is in VCO alignment. When moving L30, the voltage at the left end of R30 does not change from 8.03vdc. I have been through the entire range of L30, very carefully, with no change. I pulled out T5 and rewound it. It is as nearly perfect as I can get it. When I measure vdc on T5, I see approximately 0.01vdc on 1 and 2 and 2.65 on 3 and 4. I checked voltages on U4 and U6 and they are in the range of the table in the back of the manual. I've checked all the components installed and the soldering. This is my second K2 and I have been a lot more careful. I'm stumped. Anybody got any ideas. The second thing is that parts of the mode indicator on the display have become intermittent. Any ideas on that? Thanks. Jim, K4ZMV ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] VCO Alignment
Hello All - I ordered K2 #5329 in January, and was just able to start on it a few weeks ago. After a short break I'm back at it and this afternoon got to the Alignment and Test, Part II. All was well until I got to VCO Alignment on page 61. At first I was not able to adjust L30 and get the VCO voltage to 6.0 volts. All I could get was 7.99 volts. After reading the archives, I spread the turns on T5, and sure enough, I could get 6.0 volts at R30. But, it seems after adjusting, it drifts up slowly. So, I decided to go through the bands and see what I got. At 3500 Khz, it was a little low, and everything 7300 and above is at 7.99 volts. I've looked the board over again and again, and can't see anything wrong. Whenever I check R30 at 4000 KHz, it will be off 6.0 volts, when I adjust it back, it continues to drift, and everything above 7300 is pegged at 7.99 volts. I hope someone has some suggestions, because I'm stumped. Thanks in advance, Steve - WD7M ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] VCO Alignment
Steve, Check the number of red wire turns on T5 - count the wire as it goes threough the center of the core - counting only the outside turns can produce a numer that is one turn less than the proper number. This sounds like the sitation that occurs when there is one extra turn on T5. If you find the turns on T5 are indeed correct, the next most probable area to be investigated is the capacitors in the VFO Range Select area. If you have installed the rework eliminators, be very certain you follow the instructions for the rework eliminators carefully - the capacitors for the VFO Range select area chnge with these instructions. 73, Don W3FPR -Original Message- I ordered K2 #5329 in January, and was just able to start on it a few weeks ago. After a short break I'm back at it and this afternoon got to the Alignment and Test, Part II. All was well until I got to VCO Alignment on page 61. At first I was not able to adjust L30 and get the VCO voltage to 6.0 volts. All I could get was 7.99 volts. After reading the archives, I spread the turns on T5, and sure enough, I could get 6.0 volts at R30. But, it seems after adjusting, it drifts up slowly. So, I decided to go through the bands and see what I got. At 3500 Khz, it was a little low, and everything 7300 and above is at 7.99 volts. I've looked the board over again and again, and can't see anything wrong. Whenever I check R30 at 4000 KHz, it will be off 6.0 volts, when I adjust it back, it continues to drift, and everything above 7300 is pegged at 7.99 volts. I hope someone has some suggestions, because I'm stumped. Thanks in advance, Steve - WD7M -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.392 / Virus Database: 268.5.6/339 - Release Date: 5/14/2006 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] VCO Alignment - HOW?
I've gotten to Alignment Test, Part II RF Board build on my K2 # 5422. I seem to be having problems with VCO Alignment problems: a. 4 Mhz Oscillator Calibration = gave a reading of 12099.35 - OK it appears. b. PLL Reference Oscillator Range = 12099.32 high, to 12085.65 low - Range = 13.67khz - seems OK c. VCO Test: Frequency counter probe to VCO Test Point TP1. I got a frequency counter reading of 8913.18, seemingly stable - and OK. I'm trying to do VCO Alignment, and adjust Inductor L30 - to adjust and measure the VCO control voltage for proper range. I'M NOT SURE WHAT THE RELATIONSHIP IS BETWEEN CHANGING BANDS using the BAND+ and BAND- buttons, or changing the displayed frequency using the VFO KNOB? Which am I supposed to use? At one point, I could not get into the 80meter band with the BAND- button, without lowering the displayed frequency down to near 40 meters or lower. VCO Alignment - requires going from Band 80 to 40 to 30 to 20 to 17 to 15 to 12m to 10m. DOES THIS MEAN TO DO IT WITH THE BAND+ switch or with the VFO Knob? I tried the VCO Voltage Readings - using band/frequency changes with the VFO Knob. But then when I tried to get the low freq and high freq voltage measurements - I seemed to be getting a steady stream of 8 volts DC? HELP - can someone give me a hint on how to attack these VCO ALIGNMENT FREQUENCY CHANGES and measurements? Thanks, Fred Osborne N3CSY FL 4/22 __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] VCO Alignment - HOW?
Fred, If you attempted to change bands by moving the VFO knob, you may have the bands quite skewed. I would first try doing a 'Direct Frequency Entry' on each band (see K2 manual page 92) to get things straightened out again. Then afterward, use the BAND+ and BAND- buttons to change bands. Yes, your PLL range is just fine - concentrate on the VCO alignment (voltage at R30) - get that correct before moving on to anything else. Adjust the voltage at R30 to somewhere between 6 volts and 6.5 volts while tuned to 4000 kHz (after setting the band to 80 meters), then switch to 40 meters and check the R30 voltage at 7000 kHz - if you have the standard stuff for the K2, you should see between 1.8 and 2.2 volts at 7000 Hz. If these 2 points are within the normal range, all others should fall within range. CAUTION: if you have installed the 'rework eliminators', the procedure is quite different, and the results may be quite confusing - I have attempted to convince the 'rework eliminator' guys to avoid installing D19 and D20 and changing the value of C71 for this very reason, but they have not 'seen the light'. Unless the K60XV is actually installed, the low R30 voltage extreme at 5300 kHz cannot be observed, and correct alignment of the VCO R30 voltages is like taking a 'stab in the dark'. (Sorry for the RANT Gary, but the fact is that this condition is true and valid - D19 and D20 and C71 change the VFO range significantly - all other wiring for the K60XV can be added, but the D19, D20 and C71 should be delayed until the K60XV is actually installed). 73, Don W3FPR -Original Message- I've gotten to Alignment Test, Part II RF Board build on my K2 # 5422. I seem to be having problems with VCO Alignment problems: a. 4 Mhz Oscillator Calibration = gave a reading of 12099.35 - OK it appears. b. PLL Reference Oscillator Range = 12099.32 high, to 12085.65 low - Range = 13.67khz - seems OK c. VCO Test: Frequency counter probe to VCO Test Point TP1. I got a frequency counter reading of 8913.18, seemingly stable - and OK. I'm trying to do VCO Alignment, and adjust Inductor L30 - to adjust and measure the VCO control voltage for proper range. I'M NOT SURE WHAT THE RELATIONSHIP IS BETWEEN CHANGING BANDS using the BAND+ and BAND- buttons, or changing the displayed frequency using the VFO KNOB? Which am I supposed to use? At one point, I could not get into the 80meter band with the BAND- button, without lowering the displayed frequency down to near 40 meters or lower. VCO Alignment - requires going from Band 80 to 40 to 30 to 20 to 17 to 15 to 12m to 10m. DOES THIS MEAN TO DO IT WITH THE BAND+ switch or with the VFO Knob? I tried the VCO Voltage Readings - using band/frequency changes with the VFO Knob. But then when I tried to get the low freq and high freq voltage measurements - I seemed to be getting a steady stream of 8 volts DC? HELP - can someone give me a hint on how to attack these VCO ALIGNMENT FREQUENCY CHANGES and measurements? Thanks, Fred Osborne N3CSY FL 4/22 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] VCO Alignment problem
Hello, I am to trying the alignment the vco from my new K2 number 5351. Here is the problem, at R30 (page 61) I see no voltage. This must be 6 V. I turned at L30, that makes no difference. Everything is ok even T5. What can I do?? I have seen the troubleshooting at page 10. (PLL Reference Oscillator and VCO) and everything looks normal. I hope that you can help me. 73 Harry PA3CWQ. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] VCO Alignment problem
Harry, One of the most common problems with the PLL is a solder bridge on the thermistor board. Often you remove the front panel and control boards to gain access to the small board. Check the voltage at RF Board U6 pin 5 - if it is other than 4 volts, you can be certain that there is a problem on the thermistor board. If that does not reveal the solution, go to Appendix F of the manual and follow the steps on page 10 for PLL Reference Oscillator and VCO. If you have not yet built up the RF Probe from the parts supplied with your K2, now would be a good time to do so - unless you have a 'scope or other means of measuring RF Voltages. 73, Don W3FPR -Original Message- Hello, I am to trying the alignment the vco from my new K2 number 5351. Here is the problem, at R30 (page 61) I see no voltage. This must be 6 V. I turned at L30, that makes no difference. Everything is ok even T5. What can I do?? I have seen the troubleshooting at page 10. (PLL Reference Oscillator and VCO) and everything looks normal. I hope that you can help me. 73 Harry PA3CWQ. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] VCO alignment problem
I've been cruising through the assembly manual with no trouble at all until I got to the VCO alignment. I can't get the measured voltage at R30 down below 6.35 volts. I've installed the Rework Eliminator headers and I've set the extended vfo range menu setting D19 to 'Y'. I've double-checked the number of windings on T5 (16 red and 4 green windings), and C72 and L30 read the right value. Here's what I measure. 035002.51V 040006.35V 070002.46V 073003.77V 12.77V 101503.27V 140002.43V 150004.03V 180002.23V 182003.32V 210002.19V 214502.50V 248003.99V 250004.35V 280003.30V 288004.14V The board is assembled with an fine (.018in) solder. The label says it is lead, tin, antimony, and silver with a rosin or zinc cloride core. Does anyone have any ideas what the problem might be? Thanks in advance. Rich - KE1EV ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] VCO Alignment
I have a problem with the VCO voltage readings. When I tune L30 to read 6.00 v at 4000, I get the following: The second set of numbers is when the core of L30 is turned all the way down. Any ideas? 80M35002.12V 4.14V 40006.00V7.93V 40M70001.92V 5.11V 73003.68V7.90V 30M17.84V7.92V 10150 7.90V7.93V 20M140007.91V7.91V 15000 7.91V7.91V 17M180007.90V7.91V 18200 7.91V7.91V 15M210002.06V2.48V 21450 2.35V 2.81V 12M248007.90V7.91V 25000 7.93V 7.91V 10M280007.90V 7.90V 288007.90V 7.91 V Bob WB8DDI K2# 4998 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] VCO Alignment
Hi Gang Im building K2 4988,and on Alignment and test part 2 / VCO alignment, I could not get L30 adjusted to 6 volts on R30, Started rechecking my work as per directions,everything was fine,so directed my attention to T5,adjusted the spreadings of T5 and was able to get 6 volts at R30,My question is should I rewind T5 ,or just leave T5 alone and move on? Thanks W4GNS ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] VCO Alignment
Gary, If it is OK now, don't 'fix' it any more. If the end points for all the bands fall between 1.0 volt and 7.5 volts (1.5 to 7.0 volts is even better, but not achievable after installing the K60XV), all will be well. If you have some out of that range, you may want to re-wind T5, but spreading/squeezing the turns is a valid method of adjustment. 73, Don W3FPR -Original Message- Hi Gang Im building K2 4988,and on Alignment and test part 2 / VCO alignment, I could not get L30 adjusted to 6 volts on R30, Started rechecking my work as per directions,everything was fine,so directed my attention to T5,adjusted the spreadings of T5 and was able to get 6 volts at R30,My question is should I rewind T5 ,or just leave T5 alone and move on? Thanks W4GNS -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.338 / Virus Database: 267.9.7/60 - Release Date: 7/28/2005 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] VCO Alignment problem.
Re K2 875 I have a similar problem that Don, W3FPR had. On page 61, Turning L30 has no effect on voltage measured at R30, when frequency is at 4000 Khz. V is 8.35V. But adjusting L30 on other bands adjusts voltage! Checked L5: turns etc. C72, L30, OK. Any idea?. Yves Dussault-VE2ATD ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] VCO Alignment problem.
Yves, I don't think I was the one with the problem, but I may have been assisting someone else with that problem. Since you can adjust the voltage at R30 for other bands, we know th eoscillator is working, but it may not be working on the proper frequency. Re-check the value of C72 to be certain it is 270 pf (it is only used on 80 meters). Next re-check the number of turns on T5. Check to see that you have the correct varactors in D21 thru D26. If you have added the K60XV, the voltage at 4 MHz will normally close to the max. Since you have an older K2 serial, I am wondering if everything (especially D19 and D20) were soldered into the correct places. If those are good, set the frequency dial to 3.500 mHz and check the frequency at TP1 (use Cal FCTR or an external counter) - you will find something in the vicinity of 8.415 MHz if all is well - if it is far removed from that, you will find the problem in either the VFO frequency determining components or in the VFO range select section (check sheet 1 of the RF Board schematic to identify the components involved). 73, Don W3FPR -Original Message- Re K2 875 I have a similar problem that Don, W3FPR had. On page 61, Turning L30 has no effect on voltage measured at R30, when frequency is at 4000 Khz. V is 8.35V. But adjusting L30 on other bands adjusts voltage! Checked L5: turns etc. C72, L30, OK. Any idea?. Yves Dussault-VE2ATD -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.11.3 - Release Date: 5/3/2005 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] VCO Alignment issue
K2 s/n 4276 VCO Alignment (p61) VFO set at 4000 kHz @R30 left side = 0.018 vdc L30 verified as a 4.7 uH T005Z C72 verified as a 270 pF 271 Rewound T5 verified primary = 16 turns verified secondary = 4 Adjusting L30 has no effect on R30 voltage reading. Please advise. Thank You William Smith KC4WVL ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] VCO Alignment Troubles
Hello all (again). I'm attempting to align the VCO and am having trouble making it lock on all bands or get to the right voltage range. I've verified all components on the board and touched up the solder on the pertinent components and relays (and verified all paths/continuity), but nothing changed. Here are the voltage values I get when attempting to set L30: Low High 80M 1.937V 6.000V 40M 8.000V 8.000V 30M 0.597V 0.710V 20M 0.589V 1.148V 17M 3.054V 3.250V 15M 1.962V 2.944V 12M 1.131V 1.251V 10M 2.336V 4.060V No setting of L30 will cause 40M to lock. I also hooked up the frequency counter to TP3 per a suggestion previously on the list and it measured 8.something MHz on 40 (which doesn't seem to be right. I adjusted the spacing on the turns of T5, either pushing them apart or moving them closer. I was able to bring the lower 20M voltage up to 1.5V, but then the VFO wouldn't lock on 80. Thanks in advance for any help you can provide. (And thanks to Don for correctly surmising that my previous problem was due to a thermistor board issue.) tim -- Tim Cailloux W4EGT ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] VCO Alignment Troubles
Tim, Check and re-check the capacitor values. From the bands that seem to me to have strange voltage readings, C73 (should be 47pf) and C74 (should be 20 pf) are the most likely culprits. Other things to check: be certain the menu parameter for D19 is OFF - check the relays K13, K14 and K15, set the K2 for the band to be checked and compare the set/reset condition of each relay by checking continuity from pin to pin. The chart on the manual page just before the schematics shows which relays are set for each band and the schematic shows all relays in the reset position. The relay pin numbering is similar to that of an IC - you can locate pin 1 by finding the round solder pad on the board. 73, Don W3FPR -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Tim Cailloux Sent: Saturday, February 26, 2005 11:20 AM To: Elecraft E-mail List Subject: [Elecraft] VCO Alignment Troubles Hello all (again). I'm attempting to align the VCO and am having trouble making it lock on all bands or get to the right voltage range. I've verified all components on the board and touched up the solder on the pertinent components and relays (and verified all paths/continuity), but nothing changed. Here are the voltage values I get when attempting to set L30: Low High 80M 1.937V 6.000V 40M 8.000V 8.000V 30M 0.597V 0.710V 20M 0.589V 1.148V 17M 3.054V 3.250V 15M 1.962V 2.944V 12M 1.131V 1.251V 10M 2.336V 4.060V No setting of L30 will cause 40M to lock. I also hooked up the frequency counter to TP3 per a suggestion previously on the list and it measured 8.something MHz on 40 (which doesn't seem to be right. I adjusted the spacing on the turns of T5, either pushing them apart or moving them closer. I was able to bring the lower 20M voltage up to 1.5V, but then the VFO wouldn't lock on 80. Thanks in advance for any help you can provide. (And thanks to Don for correctly surmising that my previous problem was due to a thermistor board issue.) tim -- Tim Cailloux W4EGT ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] VCO Alignment Troubles
Check and re-check the capacitor values. From the bands that seem to me to have strange voltage readings, C73 (should be 47pf) and C74 (should be 20 pf) are the most likely culprits. Not the caps (after a quick trip to Radio Shack to pick up a new 20pf and 47pf). Other things to check: be certain the menu parameter for D19 is OFF - check the relays K13, K14 and K15, set the K2 for the band to be checked and compare the set/reset condition of each relay by checking continuity from pin to pin. Would the voltages I got make sense if I had a K14 that wasn't latching? I checked it out and it appears to be staying in the reset position. It seems that the bands I'm having voltage issues on are all connected through K14 (40, 30, 20, 12) . (The first time I checked the relays, I did the check when 80M was the last band I used. This time I checked with 40 being the band.) D19 was off. I didn't even know about the second menu until I had to look up to verify the setting! I really hope it isn't K14. I'm not looking forward to having to replace a relay. tim ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] VCO Alignment
Hello all, and thanks to those who responded to my recent message regarding the PLL reference oscillator test. I no sooner resolved that issue than I ran into a more puzzling issue during the VCO alignment. On the initial test, I had reasonable voltages through the entire band (ranging from 2.066V to 7.95V). Several high voltages, but most were well within the range. However, when I tapped the band switch button to get back down to the lower bands, everything went haywire and has not been right since. I ended up with voltages of 18mV at 4MHz and below. L30 became unresponsive. Voltages were similarly low up into about 10MHz. Then, above that, voltages moved up, and became very high, around 7.95, and again unresponsive to adjustments of L30. I could fiddle with the radio (band switching, powering off, then powering back on), and at times get back to the original readings, but I could never get the voltage down to 7.5V or below. In other words, the radio is acting very strangely. As an aside, the band switch seems to operating incorrectly in the lower bands (below 10MHz), often not switching to the lower bands at all, sometime just not switching the the proper band (ie. the next lower band). I don't know if this is a cause or and effect of the voltage problem. I am very suspicious of one or more relays because of the odd band switching. And I'll just fess up here and admit that I did (inadvertently) clip the leads on several relays AFTER soldering them; the manual says not to trim the leads. Did I mess up relays and cause the voltage problem? During the Alignment and Test: Part I, the relays seemed to work fine, but that was before I clipped any leads. I've check all values of components in and around L30, as directed in the manual. I've reheated solder joints and looked for soldering problems. I've verified the turns and connections on T5. So I'm basically at a loss. I appreciate your suggestions. Mike/NR7F ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] VCO Alignment
Mike, Since you suspect a relay problem, the easiest thing to do is check them, and actually that is mot difficult - the first page of the K2 schematic section has a chart of 'which relay is set/reset' for each band, and the schematic itself shows the relays in the reset condition. These are latching relays, so switch to the band you wish to check and then turn power off the K2. The position of the relay points can easily be determined with an ohmmeter. The pins are numbered, and pin 1 is the round solder pad (others are square). Actually the more likely thing would be that you have an unsoldered connection somewhere in the PLL/VFO area (it was making contact before, but a bit of a bump changed that). Look at the K2 schematic to identify the components in those circuits, then check each of them physically. The other thing to check carefully is the thermistor board - it is quite easy to create a solder bridge on this board. You may have to remove it to check. 73, Don W3FPR -Original Message- Hello all, and thanks to those who responded to my recent message regarding the PLL reference oscillator test. I no sooner resolved that issue than I ran into a more puzzling issue during the VCO alignment. On the initial test, I had reasonable voltages through the entire band (ranging from 2.066V to 7.95V). Several high voltages, but most were well within the range. However, when I tapped the band switch button to get back down to the lower bands, everything went haywire and has not been right since. I ended up with voltages of 18mV at 4MHz and below. L30 became unresponsive. Voltages were similarly low up into about 10MHz. Then, above that, voltages moved up, and became very high, around 7.95, and again unresponsive to adjustments of L30. I could fiddle with the radio (band switching, powering off, then powering back on), and at times get back to the original readings, but I could never get the voltage down to 7.5V or below. In other words, the radio is acting very strangely. As an aside, the band switch seems to operating incorrectly in the lower bands (below 10MHz), often not switching to the lower bands at all, sometime just not switching the the proper band (ie. the next lower band). I don't know if this is a cause or and effect of the voltage problem. I am very suspicious of one or more relays because of the odd band switching. And I'll just fess up here and admit that I did (inadvertently) clip the leads on several relays AFTER soldering them; the manual says not to trim the leads. Did I mess up relays and cause the voltage problem? During the Alignment and Test: Part I, the relays seemed to work fine, but that was before I clipped any leads. I've check all values of components in and around L30, as directed in the manual. I've reheated solder joints and looked for soldering problems. I've verified the turns and connections on T5. So I'm basically at a loss. I appreciate your suggestions. Mike/NR7F ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] VCO Alignment
I'm finally getting back to working on the K2 after two months of avoiding re-winding T5. Anyway, it's been rewound and checks out. I'm now attempting to align the VCO and am having another issue. When I connect my DMM to R30, the voltage is 17.2V and no amount of adjustment on L30 will vary that voltage. Any suggestions? I've verified L30 and C72. tim -- Tim Cailloux W4EGT ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] VCO Alignment
Tim, I would venture a good guess that you are actually reading 17.2 millivolts. If that is the case, check the 4v line out of the thermistor board - pins 6 and 7 (or U6 pin 5 - same line). I would also speculate that you will find the voltage there at 0 volts (ground). Check the back of the thermistor board carefully for solder bridges. 73, Don W3FPR -Original Message- I'm finally getting back to working on the K2 after two months of avoiding re-winding T5. Anyway, it's been rewound and checks out. I'm now attempting to align the VCO and am having another issue. When I connect my DMM to R30, the voltage is 17.2V and no amount of adjustment on L30 will vary that voltage. Any suggestions? I've verified L30 and C72. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
