Re: [Elecraft] K2 alignment and test, part III problem
Bill, I can answer your issue about the key. Make sure you use a STEREO plug. If you use a mono plug it will behave as you describe. Good luck with your no-power issue. I had the same thing which I eventually tracked down to a solder bridge on the control board. Hang in there. 73 de Al, W2GZN From: William Schmidt To: elecraft@mailman.qth.net Sent: Friday, March 2, 2012 7:50 PM Subject: [Elecraft] K2 alignment and test, part III problem I just finished up the RF board and am proceeding to the testing. Much to my dismay, however, I got no power output when I tried to adjust the 40 m BPF. I'm getting 13.5 v to all of the collectors and I pull 220 ma on receive and 420 ma on tune. The RF detector resistors and diode are correct and the transformers look good. With an RF probe I get zero volts on the xmit mixer output (U10 pin 4). So I went back further and did some basic voltage checks and found some interesting results. The key down voltage on the anode of D7 is 0 v when it should be 8 v. The anode voltage on D6 is 0.645 v on key down instead of 0 v. On receive it is 8v. I'm having some trouble getting my head around how this relates to my lack of output power. Another symptom I'm having is that the menu and display controls cease to function when I plug in a straight key. But they work ok with a paddle attached. I feel a headache starting. Any suggestions on how to proceed? Dazed and confused, Bill, WV1N __ 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
Re: [Elecraft] K2 alignment and test, part III problem
Bill, For the headache, take 2 aspirin and call me in the morning! :-) Since you do not have 8 volts on the anode of D7 during transmit, that says the 8T voltage rail is not producing voltage, and that 8T voltage is needed to power the transmit mixer and a few other transmit stages - so bottom line, it will not transmit without voltage on the 8T voltage rail. The source of your problem is on the control board, and involves Q1 and Q3 as well as the TX output from the MCU. During Transmit (or better a TUNE), the gate of Q3 should go to +5 volts, and its drain should go to zero volts. If the gate of Q3 is at 5 volts and the drain does not go to zero volts, then Q3 is damaged. The action of Q3 in turn should make Q1 conduct with the emitter at about 8 volts and the base at a lower voltage (by more than 0.6 volts) - in other words less than 7.4 volts on the base of Q1. If those conditions are true, then Q1 will conduct and 8 volts will appear at the collector of Q1. 73, Don W3FPR On 3/2/2012 7:50 PM, William Schmidt wrote: > I just finished up the RF board and am proceeding to the testing. Much to my > dismay, however, I got no power output when I tried to > adjust the 40 m BPF. I'm getting 13.5 v to all of the collectors and I pull > 220 ma on receive and 420 ma on tune. > The RF detector resistors and diode are correct and the transformers look > good. > With an RF probe I get zero volts on the xmit mixer output (U10 pin 4). > So I went back further and did some basic voltage checks and found some > interesting results. The key down voltage on the anode of D7 is > 0 v when it should be 8 v. The anode voltage on D6 is 0.645 v on key down > instead of 0 v. On receive it is 8v. > > I'm having some trouble getting my head around how this relates to my lack of > output power. Another symptom I'm having is that the menu and display > controls cease to function when I plug in a straight key. But they work ok > with a paddle attached. > > I feel a headache starting. Any suggestions on how to proceed? > > Dazed and confused, > Bill, WV1N > > __ > 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] K2 alignment and test, part III problem
I just finished up the RF board and am proceeding to the testing. Much to my dismay, however, I got no power output when I tried to adjust the 40 m BPF. I'm getting 13.5 v to all of the collectors and I pull 220 ma on receive and 420 ma on tune. The RF detector resistors and diode are correct and the transformers look good. With an RF probe I get zero volts on the xmit mixer output (U10 pin 4). So I went back further and did some basic voltage checks and found some interesting results. The key down voltage on the anode of D7 is 0 v when it should be 8 v. The anode voltage on D6 is 0.645 v on key down instead of 0 v. On receive it is 8v. I'm having some trouble getting my head around how this relates to my lack of output power. Another symptom I'm having is that the menu and display controls cease to function when I plug in a straight key. But they work ok with a paddle attached. I feel a headache starting. Any suggestions on how to proceed? Dazed and confused, Bill, WV1N __ 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 Alignment and Test, Part III
Don, I did not see obvious solder connection problems and have started the part 155 on page 7 in Troubleshooting. R67/R68, R66/R69 and D9 were visually checked. As for checking component values in the RF detector, I went to page 17 and am working on the table "RF Board". Have completed down through Q18. My measurement is listed last. D1 A 0 0 D2 A 8.0 7.8 D3 A8.0 7.8 D4 A 8.0 7.8 D5 A 0 0 D6 A 8.0 7.8D7 A 0 0 C 7.5 7.1 C7.5 7.1 C 7.5 7.15 C 7.5 7.16 C8.0 7.8 C7.5 7.2 C7.5 7.2 Q5 E 0.6, 0 Q6 B 1.0,0Q7 B 0.6,0 Q8 B 0.6,0 Q10 S 1.6, 0 Q11 E 0.0,0 Q12 S 0.0,0 B 1.3,0C13.3,13.4C13.4,13.4C 13.4,13.4 G 8.1,0 B 0.6,0G6.0,0 C 12.4,13.4 E0.4,0 E0.0,0 E0.0,0 D1.6,4.7 C1.3,0 D0.0,0 Q13 E0.6,0 Q16 E0.6,0 Q17S0.00,0 Q18G-1.0,0 B1.3,0 B0.6,.6G2.2,2.1 S2to3,1.9 C7.5,0 C2.2,2.1 D2to3,2 D6.3,7.9 Thank you, Dale, kc9cwb Dale, Go directly to troubleshooting to locate the source of the failure - you may have to get into the Transmit Signal Tracing section of Troubleshooting (look following the tables). Once you locate the failing stage, it will be easy to locate the failing component (we can help at that point - right now all we can say is that 'It's broke' ). All in all, you will most likely find a bad solder connection or unsoldered connection, and the second most likely is that you will find an incorrectly placed component. So it may be a good idea to try a good visual inspection first, you may get lucky and not have to wade through the troubleshooting. When you do get into the troubleshooting, go to section 155 Power output low and follow the steps there - do not skip around (shotgunning), do things in order and your progress will be much faster. 73, Don W3FPR ___ 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] K2 Alignment and Test, Part III
Dale, Go directly to troubleshooting to locate the source of the failure - you may have to get into the Transmit Signal Tracing section of Troubleshooting (look following the tables). Once you locate the failing stage, it will be easy to locate the failing component (we can help at that point - right now all we can say is that 'It's broke' ). All in all, you will most likely find a bad solder connection or unsoldered connection, and the second most likely is that you will find an incorrectly placed component. So it may be a good idea to try a good visual inspection first, you may get lucky and not have to wade through the troubleshooting. When you do get into the troubleshooting, go to section 155 Power output low and follow the steps there - do not skip around (shotgunning), do things in order and your progress will be much faster. 73, Don W3FPR > -Original Message- > > I have a K2 and have completed up to page 74. On page 75 the 40-Meter > Transmitter Alignment did not work. When in TUNE, my readings are .3 on > the built-in wattmeter. Adjusting L1 and L2 does not make any change. > "If you cannot get power output to 2.0 watts or higher, see > Troubleshooting". There is no increase. There is a 50 ohm dummy load > hooked to the antenna bnc. Could someone please let me know if there > is MENUE or EDIT function that may not be enabled? Should I go directly > to the Trouble shooting and take measurements? > > -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.15.9/571 - Release Date: 12/5/2006 11:50 AM ___ 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] K2 Alignment and Test, Part III
I have a K2 and have completed up to page 74. On page 75 the 40-Meter Transmitter Alignment did not work. When in TUNE, my readings are .3 on the built-in wattmeter. Adjusting L1 and L2 does not make any change. "If you cannot get power output to 2.0 watts or higher, see Troubleshooting". There is no increase. There is a 50 ohm dummy load hooked to the antenna bnc. Could someone please let me know if there is MENUE or EDIT function that may not be enabled? Should I go directly to the Trouble shooting and take measurements? Thank you, Dale, kc9cwb ___ 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: Other questions was RE: [Elecraft] K2 Alignment and Test, Part III: High current
Kathy, The K2 does not need the preamp on 40 meters. Ron D'Eau Claire wrote ion the list in Nov of 2004 how to determine when the preamp is used on the K2. I quote from his post: "The purpose of the preamp is to improve the noise figure on the higher-frequency bands, not to make the receiver louder. It does that, of course, but that's a secondary benefit. The issue is that the 'atmospheric' or 'background' noise on the higher bands - usually above 15 MHz - can be so low the internal noise in the K2 receiver could mask signals. The easiest way to tell if that's true is to turn the preamp OFF, tune your K2 to an empty frequency so all you hear is noise, set the IF filter for the narrowest bandwidth you might use, and disconnect your antenna. If then background noise level drops when you disconnect the antenna, you do *not* need the preamp. The sensitivity of the K2 is entirely limited by the background noise." 73, Gil NN4CW ___ 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: Other questions was RE: [Elecraft] K2 Alignment and Test, Part III: High current
Hi Don, I removed, checked, cleaned and reinserted T6 and T7. I also did a visual check for bad joints around Q21. I also did a side by side comparison with my FT-897 while listening in to a LSB QSO on 40m. The same antenna was used and I switched between radios using a B&W switch. Without the preamp on, the K2 exhibited better signal to noise ratio than the FT-897 with the preamp running. The K2 preamp, when engaged, amplified both noise and signal with no further improvement in quality. When the K2 preamp is switched in, the S-meter will jump from S1-S2 to +20dB (on 20m, untuned antenna). This seems to be rather large and I'm wondering if the preamp is working fine, but one of the other amps is faulty. I'm going to give the IF and post-mixer amps a good look later today. Thanks, Kathy - Original Message - From: "Don Wilhelm" <[EMAIL PROTECTED]> To: "K.Kishimoto" <[EMAIL PROTECTED]>; Sent: Monday, December 26, 2005 3:20 PM Subject: RE: Other questions was RE: [Elecraft] K2 Alignment and Test,Part III: High current Kathy, Great that you found the transmit problem - and if you can use larger wire for the power supply, the voltage drop will be less and will likely reduce your current draw on transmit a bit more. Yes, your preamp dropout problem does sound like a bad solder connection is the most likely cause. Places to check are those components associated with Q21 - look on the schematic (sheet 2) for the RF Board to identify those associated components, and don't overlook pins 4 and 7 of relay K17 and toriod T6. Actually anything in the receive chain from the antenna through the IF Amp will effect the AGC action (and subsequently the S-meter), but if the S-meter appears normal with the Preamp off, then the problem is likely confined to the preamp stage. Solve the preamp problem first and then tackle the AGC - since your S-meter seems close to normal with the preamp off, fixing the preamp may take care of the S-meter anomoly too. True the AGC (and S-meter) should not behave as you describe, but you can optimize the AGC threshold after you know everything else is working properly, then finally adjust the S-meter as the last step. 73, Don W3FPR -Original Message- Hi Don and everyone else who responded, The current readings @ 5W and 10W are now at the upper end of normal levels. T4 was reversed and needed to be turned around. The power wire is also on the thin side, 16g or 18g. I'll find a replacement tomorrow. Two new interesting problems have cropped up as well: a) 20m band, tuned Zepp: The S-meter is pegged on +40dB when the preamp is on. With the preamp off, the meter settles down to around S5 (S5-S9 when copying a signal). On 40m, antenna tuned, the LED reads +40dB with preamp and +20dB without. Tried following the S-meter setup instructions in the manual, including those on the XG1 mini-kit, but nothing seems to prevent the LED from locking into the upper limit when the preamp is on. Is this normal? The AGC can be switched on and off as well as set fast or slow. With AGC off, the S-meter drops to zero. b) The gain drops intermittently from an S-meter reading of +40dB to S2 with preamp on. The audio also diminishes in intensity at the same time. The last time it did this, I tapped the left side of the radio a couple of times and it stopped dropping out. This sounds like a loose component, bad connection or bad solder joint. Where should I begin my search? The IF stage? Could it be a toroid with a bad solder joint? Thanks, Kathy ___ 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: Other questions was RE: [Elecraft] K2 Alignment and Test, Part III: High current
Kathy, Great that you found the transmit problem - and if you can use larger wire for the power supply, the voltage drop will be less and will likely reduce your current draw on transmit a bit more. Yes, your preamp dropout problem does sound like a bad solder connection is the most likely cause. Places to check are those components associated with Q21 - look on the schematic (sheet 2) for the RF Board to identify those associated components, and don't overlook pins 4 and 7 of relay K17 and toriod T6. Actually anything in the receive chain from the antenna through the IF Amp will effect the AGC action (and subsequently the S-meter), but if the S-meter appears normal with the Preamp off, then the problem is likely confined to the preamp stage. Solve the preamp problem first and then tackle the AGC - since your S-meter seems close to normal with the preamp off, fixing the preamp may take care of the S-meter anomoly too. True the AGC (and S-meter) should not behave as you describe, but you can optimize the AGC threshold after you know everything else is working properly, then finally adjust the S-meter as the last step. 73, Don W3FPR > -Original Message- > > Hi Don and everyone else who responded, > > The current readings @ 5W and 10W are now at the upper end of > normal levels. > T4 was reversed and needed to be turned around. The power wire is also on > the thin side, 16g or 18g. I'll find a replacement tomorrow. > > Two new interesting problems have cropped up as well: > a) 20m band, tuned Zepp: The S-meter is pegged on +40dB when the > preamp is > on. With the preamp off, the meter settles down to around S5 (S5-S9 when > copying a signal). On 40m, antenna tuned, the LED reads +40dB with preamp > and +20dB without. Tried following the S-meter setup instructions in the > manual, including those on the XG1 mini-kit, but nothing seems to prevent > the LED from locking into the upper limit when the preamp is on. Is this > normal? The AGC can be switched on and off as well as set fast or > slow. With > AGC off, the S-meter drops to zero. > > b) The gain drops intermittently from an S-meter reading of +40dB > to S2 with > preamp on. The audio also diminishes in intensity at the same > time. The last > time it did this, I tapped the left side of the radio a couple of > times and > it stopped dropping out. This sounds like a loose component, bad > connection > or bad solder joint. Where should I begin my search? The IF > stage? Could it > be a toroid with a bad solder joint? > > Thanks, > Kathy > ___ 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
Other questions was RE: [Elecraft] K2 Alignment and Test, Part III: High current
Hi Don and everyone else who responded, The current readings @ 5W and 10W are now at the upper end of normal levels. T4 was reversed and needed to be turned around. The power wire is also on the thin side, 16g or 18g. I'll find a replacement tomorrow. Two new interesting problems have cropped up as well: a) 20m band, tuned Zepp: The S-meter is pegged on +40dB when the preamp is on. With the preamp off, the meter settles down to around S5 (S5-S9 when copying a signal). On 40m, antenna tuned, the LED reads +40dB with preamp and +20dB without. Tried following the S-meter setup instructions in the manual, including those on the XG1 mini-kit, but nothing seems to prevent the LED from locking into the upper limit when the preamp is on. Is this normal? The AGC can be switched on and off as well as set fast or slow. With AGC off, the S-meter drops to zero. b) The gain drops intermittently from an S-meter reading of +40dB to S2 with preamp on. The audio also diminishes in intensity at the same time. The last time it did this, I tapped the left side of the radio a couple of times and it stopped dropping out. This sounds like a loose component, bad connection or bad solder joint. Where should I begin my search? The IF stage? Could it be a toroid with a bad solder joint? Thanks, Kathy -- Message: 43 Date: Sun, 25 Dec 2005 01:44:48 -0500 From: "Don Wilhelm" <[EMAIL PROTECTED]> Subject: RE: [Elecraft] K2 Alignment and Test, Part III: High current To: "K.Kishimoto" <[EMAIL PROTECTED]>, Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="iso-8859-1" Kathy, I suggest that you tackle the voltage drop problem before investigating the current draw. What size wire are you using for the power wiring? - it should be 16 guage or larger. Next check all the connections from the power supply to the K2 - they should be tight or well soldered. If no problem is discovered in the power supply wiring itself, measure the voltage at the power supply output terminals under the load in transmit - compare to the K2 display. The K2 display should show about 0.3 volts less than the power supply output due to the protective series diode. Lastly, check the soldering in the K2 12 volt path to be certain there are no high resistance solder joints. Once you get the voltage drop under control, the current should fall in line with what is expected. You receive current draw is about normal. 73, Don W3FPR -Original Message- Power supply: SEC 1223 (23A) Unit type: K2, no options installed Passed Alignment and test, Part II Passed all resistant checks Baseline voltage and current (backlight on) 13.5v, 0.24A Transmit voltage and current into Elecraft 20W Dummy load (Using TUNE function) At 5W: 12.7v, 1.84A At 10W: 12.1v, 2.98A The current draw seems far too excessive given the suggested range in the manual. What components could potential cause this problem? The voltage drop seems high as well given the capacity of the PSU. Thanks, Kathy *Merry Christmas!* ___ 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] K2 Alignment and Test, Part III: High current
Kathy, I suggest that you tackle the voltage drop problem before investigating the current draw. What size wire are you using for the power wiring? - it should be 16 guage or larger. Next check all the connections from the power supply to the K2 - they should be tight or well soldered. If no problem is discovered in the power supply wiring itself, measure the voltage at the power supply output terminals under the load in transmit - compare to the K2 display. The K2 display should show about 0.3 volts less than the power supply output due to the protective series diode. Lastly, check the soldering in the K2 12 volt path to be certain there are no high resistance solder joints. Once you get the voltage drop under control, the current should fall in line with what is expected. You receive current draw is about normal. 73, Don W3FPR > -Original Message- > > Power supply: SEC 1223 (23A) > Unit type: K2, no options installed > Passed Alignment and test, Part II > Passed all resistant checks > > Baseline voltage and current (backlight on) > 13.5v, 0.24A > > Transmit voltage and current into Elecraft 20W Dummy load (Using TUNE > function) > At 5W: 12.7v, 1.84A > At 10W: 12.1v, 2.98A > > The current draw seems far too excessive given the suggested range in the > manual. What components could potential cause this problem? The > voltage drop > seems high as well given the capacity of the PSU. > > Thanks, > Kathy > *Merry Christmas!* > > ___ 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] K2 Alignment and Test, Part III: High current
Power supply: SEC 1223 (23A) Unit type: K2, no options installed Passed Alignment and test, Part II Passed all resistant checks Baseline voltage and current (backlight on) 13.5v, 0.24A Transmit voltage and current into Elecraft 20W Dummy load (Using TUNE function) At 5W: 12.7v, 1.84A At 10W: 12.1v, 2.98A The current draw seems far too excessive given the suggested range in the manual. What components could potential cause this problem? The voltage drop seems high as well given the capacity of the PSU. Thanks, Kathy *Merry Christmas!* ___ 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
