Re: [Elecraft] K2 audio output low after upgrades
Hi Don, Thanks for the pointers. We've just spent half an hour working through all of the steps that Chloe had gone through to install the extras and we spotted a few joints that needed touching up from the previous owner's build. Just tested the radio and we're back to full audio output. Not 100% sure which of the steps fixed it, but we're glad it's sorted. Thanks for your advice, Chloe is just finalising the re-assembly after testing so she'll be on the air again in no time. 73, Iain M0PCB On 31/08/2013 19:46, Don Wilhelm wrote: Iain, I suspect it is not really an audio problem, but a problem somewhere in the receiver front end or IF or product detector. If the S-meter is less lively than before, the problem is prior to the Product Detector, but if the S-meter has the usual response, look at the product detector and audio amp connections. Was the KAF2 plugged into the headers one pin too high - that leaves only half of the audio path operative. I would suspect the K60XV above all the other options. Pull it out of the socket and jumper J13 between pins 3 and 5 with a short wire. If the receive comes alive (it is not expected to work on 40 meters), then the K60XV is the problem spot. It is easy to remove the KAT2 for a test, just pull the cables out and connect the antenna to the base K2.. If the other options were removed, make certain they are plugged in correctly and not one pin off. You can bypass the KSB2 for receive (not transmit) with a wire jumper plugged between pins 1 and 3 of J9 and J10. The K160RX can be bypassed by putting a wire jumper between pins 1 and 7 of J14. If all those things check out OK, then look for something that was inadvertently moved during the addition of the new options. 73, Don W3FPR On 8/31/2013 11:34 AM, Iain Kelly M0PCB wrote: Greetings list, I've been assisting my partner Chloe M0GEJ with some upgrades to her K2 (s/n 5484) and we've come a bit unstuck. It's a base K2 with SSB, 160m and the KAF2. She has added the internal ATU and the 60M module. She also had to replace a faulty headphone jack on the front panel as it had gone u/s. When re-assembled we noticed the audio output level is significantly down on what it was before. The CW side-tone level is unaffected. Both the speaker and phone jack are affected. The audio level at maximum volume setting is just below normal levels required in headphonesand not very loud for internal speaker use. What we have tried: - Full receive and transmit alignment: signals are received well and showing good strength on the s-meter, both off-air and from my signal generator. - RF Gain set to Max - Checked RANT selection - Checked R1 (AGC Threshold setting) - Measured the 5V and 8V lines - Replaced U9 (LM380N-08) on the main board in case the old damaged headphone jack had caused damage. __ 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 audio output low after upgrades
Greetings list, I've been assisting my partner Chloe M0GEJ with some upgrades to her K2 (s/n 5484) and we've come a bit unstuck. It's a base K2 with SSB, 160m and the KAF2. She has added the internal ATU and the 60M module. She also had to replace a faulty headphone jack on the front panel as it had gone u/s. When re-assembled we noticed the audio output level is significantly down on what it was before. The CW side-tone level is unaffected. Both the speaker and phone jack are affected. The audio level at maximum volume setting is just below normal levels required in headphonesand not very loud for internal speaker use. What we have tried: - Full receive and transmit alignment: signals are received well and showing good strength on the s-meter, both off-air and from my signal generator. - RF Gain set to Max - Checked RANT selection - Checked R1 (AGC Threshold setting) - Measured the 5V and 8V lines - Replaced U9 (LM380N-08) on the main board in case the old damaged headphone jack had caused damage. I've had a look at Google and not turned up much that has been of much further help. Wonder if this has happened to anyone else before? Any pointers appreciated. If replying to the reflector please copy direct to my email address as I may miss responses in the daily digest. Many thanks, Iain M0PCB Chloe M0GEJ __ 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 audio output low after upgrades
Iain, I suspect it is not really an audio problem, but a problem somewhere in the receiver front end or IF or product detector. If the S-meter is less lively than before, the problem is prior to the Product Detector, but if the S-meter has the usual response, look at the product detector and audio amp connections. Was the KAF2 plugged into the headers one pin too high - that leaves only half of the audio path operative. I would suspect the K60XV above all the other options. Pull it out of the socket and jumper J13 between pins 3 and 5 with a short wire. If the receive comes alive (it is not expected to work on 40 meters), then the K60XV is the problem spot. It is easy to remove the KAT2 for a test, just pull the cables out and connect the antenna to the base K2.. If the other options were removed, make certain they are plugged in correctly and not one pin off. You can bypass the KSB2 for receive (not transmit) with a wire jumper plugged between pins 1 and 3 of J9 and J10. The K160RX can be bypassed by putting a wire jumper between pins 1 and 7 of J14. If all those things check out OK, then look for something that was inadvertently moved during the addition of the new options. 73, Don W3FPR On 8/31/2013 11:34 AM, Iain Kelly M0PCB wrote: Greetings list, I've been assisting my partner Chloe M0GEJ with some upgrades to her K2 (s/n 5484) and we've come a bit unstuck. It's a base K2 with SSB, 160m and the KAF2. She has added the internal ATU and the 60M module. She also had to replace a faulty headphone jack on the front panel as it had gone u/s. When re-assembled we noticed the audio output level is significantly down on what it was before. The CW side-tone level is unaffected. Both the speaker and phone jack are affected. The audio level at maximum volume setting is just below normal levels required in headphonesand not very loud for internal speaker use. What we have tried: - Full receive and transmit alignment: signals are received well and showing good strength on the s-meter, both off-air and from my signal generator. - RF Gain set to Max - Checked RANT selection - Checked R1 (AGC Threshold setting) - Measured the 5V and 8V lines - Replaced U9 (LM380N-08) on the main board in case the old damaged headphone jack had caused damage. __ 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
