Re: [Elecraft] KX-1 20 Meter Deafness
Don, Et Al, Looks like the unit may have had a static discharge through the antenna. Q7, part of the receiver mute circuit was blown. I'll order one tomorrow and go from there. Once I removed this component, 20 meters seems to be up there where it should be. Nothing else seems to be receiving correctly right now, but I'll attribute that to either this (now missing) part or some issue I accidentally introduced while troubleshooting. We'll see! Regards, kurtt Kurt Pawlikowski, AKA WB9FMC The Pinrod Corporation [EMAIL PROTECTED] (773) 284-9500 http://pinrod.com Don Wilhelm wrote: Kurt, From all you have said, I would believe that the problem is in the KXB3080 low pass filter. While I agree that your continuity test indicates no apparent problem with the toroid lead tinning, check all the connections to be certain there is a bit of solder on both sides of the board - if not, view that connection with suspicion. Make certain there is no contact with the green wire from L2 to the lower connection of the red wire. The green wire must wrap around to the back side of the LPF board and can inadvertently contact the #4 termination of the wire for the red winding. The best LPF testing is visual - look for any suspicious solder connections. Yes, you will see a 17 MHz cutoff on the LPF if you measure it without regard to disconnecting it from the rest of the circuit and failing to properly terminate the filter (it is not 50 ohms at the PA transistor side, but I have not ever calculated the proper termination). Perhaps it is helpful if I tell you that the green winding is the only active portion on 40, 30 and 20 meters. The red winding is used for 80 meters and SWB band below about 6 MHz only. Caution: The sensitivity of the KX1 is not as great on 20 meters as it is on 30 or 40 meters. Bringing a finger (or antenna) close to T2 or many of the receiver tuned circuits after the LPF will normally result in an increase in receiver total output, but that is actually an increase in broadband noise - under careful measurement conditions, the desired signal strength will not increase even though the overall noise level does. Spectrogram will show that is true. 73, Don W3FPR Kurt Pawlikowski wrote: Hi, First, thanks for reading. Hopefully, it won't be boring for those lucky K3 guys and gals... CONFIGURATION KX-1, 3080 upgrade. ATU currently removed and antenna jumper installed for testing.Using XG-2 as a signal source. I have confirmed the XG-2 seems to be working about as expected with another receiver (about S-10 at 50uv and S-0 (but still in the speakers) at 1uv). SYMPTOM With normal operation, receive levels appear normal on 80 and 40 (I can make contacts), but the XG2 is not peaking the KX-1's meter (I used the XG-2 to calibrate the meter). 20 meters has always seemed deaf to me. I don't remember how well the XG-2 was received on 20 when I calibrated it. Here's the real kicker: On 20 meters, with the XG-2 attached, I hear *no* volume difference between 50 and 1uv (which means the KX-1's receiver is picking up the signal by proximity, not through the antenna connection). If I touch the RX antenna connection almost anywhere between the low-pass filter and the input of the Rx Mixer (U6, pin 1), 20 meters comes way up (from nothing to receiving moderately weak signals and noise). Touching the RX antenna line on 80 and 40 appears to have little or no affect. Output power on 20 meters does not register full power, but I'm not sure if this is a calibration problem as I don't have an accurate power meter. Also, when I couple a grid dip meter into the RX, when tuned to 30 or 20 meters, I get a marked dip just at about 17 MHz. ___ 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] KX-1 20 Meter Deafness
Kurtt, The KX1 should receive just fine with Q7 removed. Any other receiver troubles are a different problem. 73, Don W3FPR Kurt Pawlikowski wrote: Don, Et Al, Looks like the unit may have had a static discharge through the antenna. Q7, part of the receiver mute circuit was blown. I'll order one tomorrow and go from there. Once I removed this component, 20 meters seems to be up there where it should be. Nothing else seems to be receiving correctly right now, but I'll attribute that to either this (now missing) part or some issue I accidentally introduced while troubleshooting. We'll see! Regards, kurtt Kurt Pawlikowski, AKA WB9FMC The Pinrod Corporation [EMAIL PROTECTED] (773) 284-9500 http://pinrod.com Don Wilhelm wrote: Kurt, From all you have said, I would believe that the problem is in the KXB3080 low pass filter. While I agree that your continuity test indicates no apparent problem with the toroid lead tinning, check all the connections to be certain there is a bit of solder on both sides of the board - if not, view that connection with suspicion. Make certain there is no contact with the green wire from L2 to the lower connection of the red wire. The green wire must wrap around to the back side of the LPF board and can inadvertently contact the #4 termination of the wire for the red winding. The best LPF testing is visual - look for any suspicious solder connections. Yes, you will see a 17 MHz cutoff on the LPF if you measure it without regard to disconnecting it from the rest of the circuit and failing to properly terminate the filter (it is not 50 ohms at the PA transistor side, but I have not ever calculated the proper termination). Perhaps it is helpful if I tell you that the green winding is the only active portion on 40, 30 and 20 meters. The red winding is used for 80 meters and SWB band below about 6 MHz only. Caution: The sensitivity of the KX1 is not as great on 20 meters as it is on 30 or 40 meters. Bringing a finger (or antenna) close to T2 or many of the receiver tuned circuits after the LPF will normally result in an increase in receiver total output, but that is actually an increase in broadband noise - under careful measurement conditions, the desired signal strength will not increase even though the overall noise level does. Spectrogram will show that is true. 73, Don W3FPR Kurt Pawlikowski wrote: Hi, First, thanks for reading. Hopefully, it won't be boring for those lucky K3 guys and gals... CONFIGURATION KX-1, 3080 upgrade. ATU currently removed and antenna jumper installed for testing.Using XG-2 as a signal source. I have confirmed the XG-2 seems to be working about as expected with another receiver (about S-10 at 50uv and S-0 (but still in the speakers) at 1uv). SYMPTOM With normal operation, receive levels appear normal on 80 and 40 (I can make contacts), but the XG2 is not peaking the KX-1's meter (I used the XG-2 to calibrate the meter). 20 meters has always seemed deaf to me. I don't remember how well the XG-2 was received on 20 when I calibrated it. Here's the real kicker: On 20 meters, with the XG-2 attached, I hear *no* volume difference between 50 and 1uv (which means the KX-1's receiver is picking up the signal by proximity, not through the antenna connection). If I touch the RX antenna connection almost anywhere between the low-pass filter and the input of the Rx Mixer (U6, pin 1), 20 meters comes way up (from nothing to receiving moderately weak signals and noise). Touching the RX antenna line on 80 and 40 appears to have little or no affect. Output power on 20 meters does not register full power, but I'm not sure if this is a calibration problem as I don't have an accurate power meter. Also, when I couple a grid dip meter into the RX, when tuned to 30 or 20 meters, I get a marked dip just at about 17 MHz. No virus found in this incoming message. Checked by AVG. Version: 8.0.100 / Virus Database: 269.23.21/1458 - Release Date: 5/21/2008 7:21 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
Re: [Elecraft] KX-1 20 Meter Deafness
Don, I suspected that. At any rate, I've either blown something else (seems 40 almost worked before I started troubleshooting!) or more than that one component was damaged. Gonna have to maybe mess with the LXB3030 with it's SMT stuff. I'm thinking that if that's damaged, its the most expensive single part of the 3080 kit! Of course, the more I think about it, the more it seems it'll be at least part of the remaining issues... Regards, kurtt Kurt Pawlikowski, AKA WB9FMC The Pinrod Corporation [EMAIL PROTECTED] (773) 284-9500 http://pinrod.com Don Wilhelm wrote: Kurtt, The KX1 should receive just fine with Q7 removed. Any other receiver troubles are a different problem. 73, Don W3FPR Kurt Pawlikowski wrote: Don, Et Al, Looks like the unit may have had a static discharge through the antenna. Q7, part of the receiver mute circuit was blown. I'll order one tomorrow and go from there. Once I removed this component, 20 meters seems to be up there where it should be. Nothing else seems to be receiving correctly right now, but I'll attribute that to either this (now missing) part or some issue I accidentally introduced while troubleshooting. We'll see! Regards, kurtt Kurt Pawlikowski, AKA WB9FMC The Pinrod Corporation [EMAIL PROTECTED] (773) 284-9500 http://pinrod.com Don Wilhelm wrote: Kurt, From all you have said, I would believe that the problem is in the KXB3080 low pass filter. While I agree that your continuity test indicates no apparent problem with the toroid lead tinning, check all the connections to be certain there is a bit of solder on both sides of the board - if not, view that connection with suspicion. Make certain there is no contact with the green wire from L2 to the lower connection of the red wire. The green wire must wrap around to the back side of the LPF board and can inadvertently contact the #4 termination of the wire for the red winding. The best LPF testing is visual - look for any suspicious solder connections. Yes, you will see a 17 MHz cutoff on the LPF if you measure it without regard to disconnecting it from the rest of the circuit and failing to properly terminate the filter (it is not 50 ohms at the PA transistor side, but I have not ever calculated the proper termination). Perhaps it is helpful if I tell you that the green winding is the only active portion on 40, 30 and 20 meters. The red winding is used for 80 meters and SWB band below about 6 MHz only. Caution: The sensitivity of the KX1 is not as great on 20 meters as it is on 30 or 40 meters. Bringing a finger (or antenna) close to T2 or many of the receiver tuned circuits after the LPF will normally result in an increase in receiver total output, but that is actually an increase in broadband noise - under careful measurement conditions, the desired signal strength will not increase even though the overall noise level does. Spectrogram will show that is true. 73, Don W3FPR Kurt Pawlikowski wrote: Hi, First, thanks for reading. Hopefully, it won't be boring for those lucky K3 guys and gals... CONFIGURATION KX-1, 3080 upgrade. ATU currently removed and antenna jumper installed for testing.Using XG-2 as a signal source. I have confirmed the XG-2 seems to be working about as expected with another receiver (about S-10 at 50uv and S-0 (but still in the speakers) at 1uv). SYMPTOM With normal operation, receive levels appear normal on 80 and 40 (I can make contacts), but the XG2 is not peaking the KX-1's meter (I used the XG-2 to calibrate the meter). 20 meters has always seemed deaf to me. I don't remember how well the XG-2 was received on 20 when I calibrated it. Here's the real kicker: On 20 meters, with the XG-2 attached, I hear *no* volume difference between 50 and 1uv (which means the KX-1's receiver is picking up the signal by proximity, not through the antenna connection). If I touch the RX antenna connection almost anywhere between the low-pass filter and the input of the Rx Mixer (U6, pin 1), 20 meters comes way up (from nothing to receiving moderately weak signals and noise). Touching the RX antenna line on 80 and 40 appears to have little or no affect. Output power on 20 meters does not register full power, but I'm not sure if this is a calibration problem as I don't have an accurate power meter. Also, when I couple a grid dip meter into the RX, when tuned to 30 or 20 meters, I get a marked dip just at about 17 MHz. No virus found in this incoming message. Checked by AVG. Version: 8.0.100 / Virus Database: 269.23.21/1458 - Release Date: 5/21/2008 7:21 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.):
Re: [Elecraft] KX-1 20 Meter Deafness
Kurtt, If you suspect the KXB3080 board strongly enough, disconnect one end of the A, B and C wires to that board and it will be removed from the front end circuits. It is easy to remove the A and B wires from the KXB3080 board (solder them back on the top of the board). The C wire is the hardest to remove - but if you have a de-soldering gun, you can suck the solder from both ends of the wire and pull it straight out - to replace, just put a long wire through both holes, solder and clip the ends. Do not remove T2 and the board capacitors added with the KXB3080 - those should tune to 20 and 40 with the KXB3080 removed, but you will have to re-peak the trimmers to compensate for the stray capacitance on the KXB3080 board and the wires. 73, Don W3FPR Kurt Pawlikowski wrote: Don, I suspected that. At any rate, I've either blown something else (seems 40 almost worked before I started troubleshooting!) or more than that one component was damaged. Gonna have to maybe mess with the LXB3030 with it's SMT stuff. I'm thinking that if that's damaged, its the most expensive single part of the 3080 kit! Of course, the more I think about it, the more it seems it'll be at least part of the remaining issues... Regards, kurtt Kurt Pawlikowski, AKA WB9FMC The Pinrod Corporation [EMAIL PROTECTED] (773) 284-9500 http://pinrod.com Don Wilhelm wrote: Kurtt, The KX1 should receive just fine with Q7 removed. Any other receiver troubles are a different problem. 73, Don W3FPR Kurt Pawlikowski wrote: Don, Et Al, Looks like the unit may have had a static discharge through the antenna. Q7, part of the receiver mute circuit was blown. I'll order one tomorrow and go from there. Once I removed this component, 20 meters seems to be up there where it should be. Nothing else seems to be receiving correctly right now, but I'll attribute that to either this (now missing) part or some issue I accidentally introduced while troubleshooting. We'll see! Regards, kurtt Kurt Pawlikowski, AKA WB9FMC The Pinrod Corporation [EMAIL PROTECTED] (773) 284-9500 http://pinrod.com Don Wilhelm wrote: Kurt, From all you have said, I would believe that the problem is in the KXB3080 low pass filter. While I agree that your continuity test indicates no apparent problem with the toroid lead tinning, check all the connections to be certain there is a bit of solder on both sides of the board - if not, view that connection with suspicion. Make certain there is no contact with the green wire from L2 to the lower connection of the red wire. The green wire must wrap around to the back side of the LPF board and can inadvertently contact the #4 termination of the wire for the red winding. The best LPF testing is visual - look for any suspicious solder connections. Yes, you will see a 17 MHz cutoff on the LPF if you measure it without regard to disconnecting it from the rest of the circuit and failing to properly terminate the filter (it is not 50 ohms at the PA transistor side, but I have not ever calculated the proper termination). Perhaps it is helpful if I tell you that the green winding is the only active portion on 40, 30 and 20 meters. The red winding is used for 80 meters and SWB band below about 6 MHz only. Caution: The sensitivity of the KX1 is not as great on 20 meters as it is on 30 or 40 meters. Bringing a finger (or antenna) close to T2 or many of the receiver tuned circuits after the LPF will normally result in an increase in receiver total output, but that is actually an increase in broadband noise - under careful measurement conditions, the desired signal strength will not increase even though the overall noise level does. Spectrogram will show that is true. 73, Don W3FPR Kurt Pawlikowski wrote: Hi, First, thanks for reading. Hopefully, it won't be boring for those lucky K3 guys and gals... CONFIGURATION KX-1, 3080 upgrade. ATU currently removed and antenna jumper installed for testing.Using XG-2 as a signal source. I have confirmed the XG-2 seems to be working about as expected with another receiver (about S-10 at 50uv and S-0 (but still in the speakers) at 1uv). SYMPTOM With normal operation, receive levels appear normal on 80 and 40 (I can make contacts), but the XG2 is not peaking the KX-1's meter (I used the XG-2 to calibrate the meter). 20 meters has always seemed deaf to me. I don't remember how well the XG-2 was received on 20 when I calibrated it. Here's the real kicker: On 20 meters, with the XG-2 attached, I hear *no* volume difference between 50 and 1uv (which means the KX-1's receiver is picking up the signal by proximity, not through the antenna connection). If I touch the RX antenna connection almost anywhere between the low-pass filter and the input of the Rx Mixer (U6, pin 1), 20 meters comes way up (from nothing to receiving moderately weak signals and noise). Touching the
Re: [Elecraft] KX-1 20 Meter Deafness
Don, Still frustrated... I removed the LPF board and removed both L1 and L2. I then hard wired them in, just the way they would be with the board and the relay off. This had no affect on the symptoms: The XG-2 signal still seems to be being coupled direct to the board (1 uv 50 uv switch does not change tone volume). The next step is to drag down my boat anchor oscilloscope and take some measurements. I expect the signal level before T2 to be too small for my old equipment to see (I don't think it'll do micro volts - I'll have to check though.). Anyway, with the XG-2 on 20 meters, what signal strength (p-p) should I be seeing at different points of the circuit? I'm thinking of several points between the antenna up to the mixer with both the 50 and 1 uv output (I may have a hard time measuring the 50 uv level, much less the 1!). Any other ideas are welcome... Regards, kurtt Kurt Pawlikowski, AKA WB9FMC The Pinrod Corporation [EMAIL PROTECTED] (773) 284-9500 http://pinrod.com Don Wilhelm wrote: Kurt, From all you have said, I would believe that the problem is in the KXB3080 low pass filter. While I agree that your continuity test indicates no apparent problem with the toroid lead tinning, check all the connections to be certain there is a bit of solder on both sides of the board - if not, view that connection with suspicion. Make certain there is no contact with the green wire from L2 to the lower connection of the red wire. The green wire must wrap around to the back side of the LPF board and can inadvertently contact the #4 termination of the wire for the red winding. The best LPF testing is visual - look for any suspicious solder connections. Yes, you will see a 17 MHz cutoff on the LPF if you measure it without regard to disconnecting it from the rest of the circuit and failing to properly terminate the filter (it is not 50 ohms at the PA transistor side, but I have not ever calculated the proper termination). Perhaps it is helpful if I tell you that the green winding is the only active portion on 40, 30 and 20 meters. The red winding is used for 80 meters and SWB band below about 6 MHz only. Caution: The sensitivity of the KX1 is not as great on 20 meters as it is on 30 or 40 meters. Bringing a finger (or antenna) close to T2 or many of the receiver tuned circuits after the LPF will normally result in an increase in receiver total output, but that is actually an increase in broadband noise - under careful measurement conditions, the desired signal strength will not increase even though the overall noise level does. Spectrogram will show that is true. 73, Don W3FPR Kurt Pawlikowski wrote: Hi, First, thanks for reading. Hopefully, it won't be boring for those lucky K3 guys and gals... CONFIGURATION KX-1, 3080 upgrade. ATU currently removed and antenna jumper installed for testing.Using XG-2 as a signal source. I have confirmed the XG-2 seems to be working about as expected with another receiver (about S-10 at 50uv and S-0 (but still in the speakers) at 1uv). SYMPTOM With normal operation, receive levels appear normal on 80 and 40 (I can make contacts), but the XG2 is not peaking the KX-1's meter (I used the XG-2 to calibrate the meter). 20 meters has always seemed deaf to me. I don't remember how well the XG-2 was received on 20 when I calibrated it. Here's the real kicker: On 20 meters, with the XG-2 attached, I hear *no* volume difference between 50 and 1uv (which means the KX-1's receiver is picking up the signal by proximity, not through the antenna connection). If I touch the RX antenna connection almost anywhere between the low-pass filter and the input of the Rx Mixer (U6, pin 1), 20 meters comes way up (from nothing to receiving moderately weak signals and noise). Touching the RX antenna line on 80 and 40 appears to have little or no affect. Output power on 20 meters does not register full power, but I'm not sure if this is a calibration problem as I don't have an accurate power meter. Also, when I couple a grid dip meter into the RX, when tuned to 30 or 20 meters, I get a marked dip just at about 17 MHz. ___ 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] KX-1 20 Meter Deafness
Mike, While my pride as a builder says, No way! you are probably right and I'll probably have to rebuild that board. To paraphrase a quote: We hates it Mr. Baggins... Regards, kurtt Kurt Pawlikowski, AKA WB9FMC The Pinrod Corporation [EMAIL PROTECTED] (773) 284-9500 http://pinrod.com Mike wrote: Kurt, For what it's worth, when I built my KX-1 I had very similar problems. I wound up sending a pic of my LPF board to Don, who spotted the slightest hint of enamel insulation in one of the toroid solder joints. I had to look at it 4 times before I could even see it. Anyway, I wound up pretty much rebuilding that board and it was fine after that. It's *very* finicky. -- 73, Mike, KC0KBC -- Original message -- From: Kurt Pawlikowski [EMAIL PROTECTED] Don, I'll check the LPF board closely. As far as whether the signal increase, I believe it does. Since, when I touch it, signals I an hearing on my other receiver become apparent in the KX-1 also. And, I believe the XG-2 signal is increasing (only by ear). I say that because the increase is very noticeable: From, Is it there? to I have to turn it down. Which is quite a jump (probably 9dB). Anyway, I'll look it over more closely (maybe rebuild that board) and report back. Thanks. Regards, kurtt Kurt Pawlikowski, AKA WB9FMC The Pinrod Corporation [EMAIL PROTECTED] (773) 284-9500 http://pinrod.com Don Wilhelm wrote: Kurt, From all you have said, I would believe that the problem is in the KXB3080 low pass filter. While I agree that your continuity test indicates no apparent problem with the toroid lead tinning, check all the connections to be certain there is a bit of solder on both sides of the board - if not, view that connection with suspicion. Make certain there is no contact with the green wire from L2 to the lower connection of the red wire. The green wire must wrap around to the back side of the LPF board and can inadvertently contact the #4 termination of the wire for the red winding. The best LPF testing is visual - look for any suspicious solder connections. Yes, you will see a 17 MHz cutoff on the LPF if you measure it without regard to disconnecting it from the rest of the circuit and failing to properly terminate the filter (it is not 50 ohms at the PA transistor side, but I have not ever calculated the proper termination). Perhaps it is helpful if I tell you that the green winding is the only active portion on 40, 30 and 20 meters. The red winding is used for 80 meters and SWB band below about 6 MHz only. Caution: The sensitivity of the KX1 is not as great on 20 meters as it is on 30 or 40 meters. Bringing a finger (or antenna) close to T2 or many of the receiver tuned circuits after the LPF will normally result in an increase in receiver total output, but that is actually an increase in broadband noise - under careful measurement conditions, the desired signal strength will not increase even though the overall noise level does. Spectrogram will show that is true. 73, Don W3FPR Kurt Pawlikowski wrote: Hi, First, thanks for reading. Hopefully, it won't be boring for those lucky K3 guys and gals... CONFIGURATION KX-1, 3080 upgrade. ATU currently removed and antenna jumper installed for testing.Using XG-2 as a signal source. I have confirmed the XG-2 seems to be working about as expected with another receiver (about S-10 at 50uv and S-0 (but still in the speakers) at 1uv). SYMPTOM With normal operation, receive levels appear normal on 80 and 40 (I can make contacts), but the XG2 is not peaking the KX-1's meter (I used the XG-2 to calibrate the meter). 20 meters has always seemed deaf to me. I don't remember how well the XG-2 was received on 20 when I calibrated it. Here's the real kicker: On 20 meters, with the XG-2 attached, I hear *no* volume difference between 50 and 1uv (which means the KX-1's receiver is picking up the signal by proximity, not through the antenna connection). If I touch the RX antenna connection almost anywhere between the low-pass filter and the input of the Rx Mixer (U6, pin 1), 20 meters comes way up (from nothing to receiving moderately weak signals and noise). Touching the RX antenna line on 80 and 40 appears to have little or no affect. Output power on 20 meters does not register full power, but I'm not sure if this is a calibration problem as I don't have an accurate power meter. Also, when I couple a grid dip meter into the RX, when tuned to 30 or 20 meters, I get a marked dip just at about 17 MHz. ___ 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:
[Elecraft] KX-1 20 Meter Deafness
Hi, First, thanks for reading. Hopefully, it won't be boring for those lucky K3 guys and gals... CONFIGURATION KX-1, 3080 upgrade. ATU currently removed and antenna jumper installed for testing.Using XG-2 as a signal source. I have confirmed the XG-2 seems to be working about as expected with another receiver (about S-10 at 50uv and S-0 (but still in the speakers) at 1uv). SYMPTOM With normal operation, receive levels appear normal on 80 and 40 (I can make contacts), but the XG2 is not peaking the KX-1's meter (I used the XG-2 to calibrate the meter). 20 meters has always seemed deaf to me. I don't remember how well the XG-2 was received on 20 when I calibrated it. Here's the real kicker: On 20 meters, with the XG-2 attached, I hear *no* volume difference between 50 and 1uv (which means the KX-1's receiver is picking up the signal by proximity, not through the antenna connection). If I touch the RX antenna connection almost anywhere between the low-pass filter and the input of the Rx Mixer (U6, pin 1), 20 meters comes way up (from nothing to receiving moderately weak signals and noise). Touching the RX antenna line on 80 and 40 appears to have little or no affect. Output power on 20 meters does not register full power, but I'm not sure if this is a calibration problem as I don't have an accurate power meter. Also, when I couple a grid dip meter into the RX, when tuned to 30 or 20 meters, I get a marked dip just at about 17 MHz. REASONING AND TROUBLESHOOTING These are the things I've done and why... 1) Tested continuity between the antenna input and CA (measures about 0.2 ohm). If I had messed up any of the connections on the 8030 coil board, I would have expected an open. 0.2 ohms *seems* consistent. 2) Disconnected leads A and B from the 3080 board (thought they might have been interfering). 3) I inspected the 8030 coil board coil winding and installation. They appear okay. 4) I checked that T2 is wound and installed correctly. 5) I have checked the values of capacitors in the low-pass filter and mixer circuits (marked values only - not measured). 6) I've inspected the solder connections (connections seem to be verified by continuity tests). 7) I've made sure the relays, K1 and K2, are in the proper state (Normal for 30 and 20 meters - Added capacitors are disconnected). 8) I've verified control voltages on the 8030 SMT board. 9) I've verified the 8030 SMT connections are to the proper places (since I've disconnected the A and B wires and injecting a signal into the Rx Antenna input seems to work well, I'm assuming that wire C is not at fault). 10) I made sure D7 is properly installed. I expect if it was not, I'd get no power out at all. 11) Scanned QTH's news group archive for KX-1 Rx problems, which had some suggestions, but only one solution was listed. (I don't care for their search facility) OTHER I'm sure I've missed something... probably obvious. I guess the next step is to build an RF probe (though I expect the levels where the problem is will be very difficult to measure) and drag down the boat anchor Oscilloscope (which probably doesn't have the sensitivity to trace the signal). Gives me an idea: I'll take my other radio and see if I can trace the signal through the circuits. I expect I won't see it on the RX ANT connection, which is telling me the same thing I think I'm surmising above. Okay. Well, that's all I can think of just now. If anyone has any suggestions or comments, please feel free to contact me on and/or off list. Thanks. Regards, kurtt Kurt Pawlikowski, AKA WB9FMC The Pinrod Corporation [EMAIL PROTECTED] (773) 284-9500 http://pinrod.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] KX-1 20 Meter Deafness
Kurt, From all you have said, I would believe that the problem is in the KXB3080 low pass filter. While I agree that your continuity test indicates no apparent problem with the toroid lead tinning, check all the connections to be certain there is a bit of solder on both sides of the board - if not, view that connection with suspicion. Make certain there is no contact with the green wire from L2 to the lower connection of the red wire. The green wire must wrap around to the back side of the LPF board and can inadvertently contact the #4 termination of the wire for the red winding. The best LPF testing is visual - look for any suspicious solder connections. Yes, you will see a 17 MHz cutoff on the LPF if you measure it without regard to disconnecting it from the rest of the circuit and failing to properly terminate the filter (it is not 50 ohms at the PA transistor side, but I have not ever calculated the proper termination). Perhaps it is helpful if I tell you that the green winding is the only active portion on 40, 30 and 20 meters. The red winding is used for 80 meters and SWB band below about 6 MHz only. Caution: The sensitivity of the KX1 is not as great on 20 meters as it is on 30 or 40 meters. Bringing a finger (or antenna) close to T2 or many of the receiver tuned circuits after the LPF will normally result in an increase in receiver total output, but that is actually an increase in broadband noise - under careful measurement conditions, the desired signal strength will not increase even though the overall noise level does. Spectrogram will show that is true. 73, Don W3FPR Kurt Pawlikowski wrote: Hi, First, thanks for reading. Hopefully, it won't be boring for those lucky K3 guys and gals... CONFIGURATION KX-1, 3080 upgrade. ATU currently removed and antenna jumper installed for testing.Using XG-2 as a signal source. I have confirmed the XG-2 seems to be working about as expected with another receiver (about S-10 at 50uv and S-0 (but still in the speakers) at 1uv). SYMPTOM With normal operation, receive levels appear normal on 80 and 40 (I can make contacts), but the XG2 is not peaking the KX-1's meter (I used the XG-2 to calibrate the meter). 20 meters has always seemed deaf to me. I don't remember how well the XG-2 was received on 20 when I calibrated it. Here's the real kicker: On 20 meters, with the XG-2 attached, I hear *no* volume difference between 50 and 1uv (which means the KX-1's receiver is picking up the signal by proximity, not through the antenna connection). If I touch the RX antenna connection almost anywhere between the low-pass filter and the input of the Rx Mixer (U6, pin 1), 20 meters comes way up (from nothing to receiving moderately weak signals and noise). Touching the RX antenna line on 80 and 40 appears to have little or no affect. Output power on 20 meters does not register full power, but I'm not sure if this is a calibration problem as I don't have an accurate power meter. Also, when I couple a grid dip meter into the RX, when tuned to 30 or 20 meters, I get a marked dip just at about 17 MHz. ___ 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] KX-1 20 Meter Deafness
Don, I'll check the LPF board closely. As far as whether the signal increase, I believe it does. Since, when I touch it, signals I an hearing on my other receiver become apparent in the KX-1 also. And, I believe the XG-2 signal is increasing (only by ear). I say that because the increase is very noticeable: From, Is it there? to I have to turn it down. Which is quite a jump (probably 9dB). Anyway, I'll look it over more closely (maybe rebuild that board) and report back. Thanks. Regards, kurtt Kurt Pawlikowski, AKA WB9FMC The Pinrod Corporation [EMAIL PROTECTED] (773) 284-9500 http://pinrod.com Don Wilhelm wrote: Kurt, From all you have said, I would believe that the problem is in the KXB3080 low pass filter. While I agree that your continuity test indicates no apparent problem with the toroid lead tinning, check all the connections to be certain there is a bit of solder on both sides of the board - if not, view that connection with suspicion. Make certain there is no contact with the green wire from L2 to the lower connection of the red wire. The green wire must wrap around to the back side of the LPF board and can inadvertently contact the #4 termination of the wire for the red winding. The best LPF testing is visual - look for any suspicious solder connections. Yes, you will see a 17 MHz cutoff on the LPF if you measure it without regard to disconnecting it from the rest of the circuit and failing to properly terminate the filter (it is not 50 ohms at the PA transistor side, but I have not ever calculated the proper termination). Perhaps it is helpful if I tell you that the green winding is the only active portion on 40, 30 and 20 meters. The red winding is used for 80 meters and SWB band below about 6 MHz only. Caution: The sensitivity of the KX1 is not as great on 20 meters as it is on 30 or 40 meters. Bringing a finger (or antenna) close to T2 or many of the receiver tuned circuits after the LPF will normally result in an increase in receiver total output, but that is actually an increase in broadband noise - under careful measurement conditions, the desired signal strength will not increase even though the overall noise level does. Spectrogram will show that is true. 73, Don W3FPR Kurt Pawlikowski wrote: Hi, First, thanks for reading. Hopefully, it won't be boring for those lucky K3 guys and gals... CONFIGURATION KX-1, 3080 upgrade. ATU currently removed and antenna jumper installed for testing.Using XG-2 as a signal source. I have confirmed the XG-2 seems to be working about as expected with another receiver (about S-10 at 50uv and S-0 (but still in the speakers) at 1uv). SYMPTOM With normal operation, receive levels appear normal on 80 and 40 (I can make contacts), but the XG2 is not peaking the KX-1's meter (I used the XG-2 to calibrate the meter). 20 meters has always seemed deaf to me. I don't remember how well the XG-2 was received on 20 when I calibrated it. Here's the real kicker: On 20 meters, with the XG-2 attached, I hear *no* volume difference between 50 and 1uv (which means the KX-1's receiver is picking up the signal by proximity, not through the antenna connection). If I touch the RX antenna connection almost anywhere between the low-pass filter and the input of the Rx Mixer (U6, pin 1), 20 meters comes way up (from nothing to receiving moderately weak signals and noise). Touching the RX antenna line on 80 and 40 appears to have little or no affect. Output power on 20 meters does not register full power, but I'm not sure if this is a calibration problem as I don't have an accurate power meter. Also, when I couple a grid dip meter into the RX, when tuned to 30 or 20 meters, I get a marked dip just at about 17 MHz. ___ 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] KX-1 20 Meter Deafness
Don, Okay... Frustrated, but here's what I found On the LPF1 board, L1, 1 and 4 were reversed and shorted together. This means that, for all intents and purposes, L1 was a wire. Okay, well, it's a wire anyway, but with a lot less inductance. You know what I mean! Hi, hi... This might explain my lower power on 20. I haven't fully checked it out yet. Anyway, even after fixing this error, it is still exhibiting the same problem on 20 meters (seems to be receiving by induction instead of through the antenna connection). Also, particularly on 20, touching the RX ANT connection increases the gain (confirmed by spectrograph program). Again, I seem to have continuity. Well, I think that's it for tonight. I can't think of anything else to look at right now. There is obviously something else wrong... Regards, kurtt Kurt Pawlikowski, AKA WB9FMC The Pinrod Corporation [EMAIL PROTECTED] (773) 284-9500 http://pinrod.com Don Wilhelm wrote: Kurt, From all you have said, I would believe that the problem is in the KXB3080 low pass filter. While I agree that your continuity test indicates no apparent problem with the toroid lead tinning, check all the connections to be certain there is a bit of solder on both sides of the board - if not, view that connection with suspicion. Make certain there is no contact with the green wire from L2 to the lower connection of the red wire. The green wire must wrap around to the back side of the LPF board and can inadvertently contact the #4 termination of the wire for the red winding. The best LPF testing is visual - look for any suspicious solder connections. Yes, you will see a 17 MHz cutoff on the LPF if you measure it without regard to disconnecting it from the rest of the circuit and failing to properly terminate the filter (it is not 50 ohms at the PA transistor side, but I have not ever calculated the proper termination). Perhaps it is helpful if I tell you that the green winding is the only active portion on 40, 30 and 20 meters. The red winding is used for 80 meters and SWB band below about 6 MHz only. Caution: The sensitivity of the KX1 is not as great on 20 meters as it is on 30 or 40 meters. Bringing a finger (or antenna) close to T2 or many of the receiver tuned circuits after the LPF will normally result in an increase in receiver total output, but that is actually an increase in broadband noise - under careful measurement conditions, the desired signal strength will not increase even though the overall noise level does. Spectrogram will show that is true. 73, Don W3FPR Kurt Pawlikowski wrote: Hi, First, thanks for reading. Hopefully, it won't be boring for those lucky K3 guys and gals... CONFIGURATION KX-1, 3080 upgrade. ATU currently removed and antenna jumper installed for testing.Using XG-2 as a signal source. I have confirmed the XG-2 seems to be working about as expected with another receiver (about S-10 at 50uv and S-0 (but still in the speakers) at 1uv). SYMPTOM With normal operation, receive levels appear normal on 80 and 40 (I can make contacts), but the XG2 is not peaking the KX-1's meter (I used the XG-2 to calibrate the meter). 20 meters has always seemed deaf to me. I don't remember how well the XG-2 was received on 20 when I calibrated it. Here's the real kicker: On 20 meters, with the XG-2 attached, I hear *no* volume difference between 50 and 1uv (which means the KX-1's receiver is picking up the signal by proximity, not through the antenna connection). If I touch the RX antenna connection almost anywhere between the low-pass filter and the input of the Rx Mixer (U6, pin 1), 20 meters comes way up (from nothing to receiving moderately weak signals and noise). Touching the RX antenna line on 80 and 40 appears to have little or no affect. Output power on 20 meters does not register full power, but I'm not sure if this is a calibration problem as I don't have an accurate power meter. Also, when I couple a grid dip meter into the RX, when tuned to 30 or 20 meters, I get a marked dip just at about 17 MHz. ___ 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
