[Elecraft] [K2] Sidetone has suddenly disappeared.
My K2 suddenly quit supplying a sidetone. Changing sidetone level and frequency do nothing. Per the troubleshooting guide, I've found that the drain of Q5 has no AC voltage when key down, while pin one of U10 (IIRC) is supplying 5 volts (and pin 25 of the IC in the previous step had expected 2.5v AC). So, this seems to mean that Q5 is bad, but when I pulled it and tested it with the M3 semiconductor analyzer, it is not obviously bad (to me anyway). It reads NMOS Vth=1.76v, S-G-D mA=1.13 - whatever that means, I don't know enough to interpret. Any off the cuff ideas? I have a replacement 2n7000 on the way, but still wondering why it would fail in circuit, and if its really bad. Thanks, Chip AE5KA __ 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] Sidetone has suddenly disappeared.
Chip, I suspect that you accidentally toggled the sidetone source in the menu. If your K2 SN is 3000 or greater, or you have an earlier K2 with the KPA100 or KIO2 added, you need to select U8-4 for the sidetone source. If none of those conditions match, the sidetone source is U6-25. If you put Q5 back in the circuit, enter the menu for St L, hold EDIT to edit the parameter, and first set the level at something reasonable - between 20 and 40 - then tap the DISPLAY button to toggle the source. When you hear sidetone, stop and exit the menu. To prevent future occurrences, I suggest that you do not set a PF key to St L. When zero-beating, adjust the audio level on the signal (to match the sidetone level) with the AF Gain control instead of adjusting the level of the sidetone to match whatever signal level you have. 73, Don W3FPR On 7/28/2011 7:37 AM, Chip Stratton wrote: > My K2 suddenly quit supplying a sidetone. Changing sidetone level and > frequency do nothing. > > Per the troubleshooting guide, I've found that the drain of Q5 has no AC > voltage when key down, while pin one of U10 (IIRC) is supplying 5 volts (and > pin 25 of the IC in the previous step had expected 2.5v AC). > > So, this seems to mean that Q5 is bad, but when I pulled it and tested it > with the M3 semiconductor analyzer, it is not obviously bad (to me anyway). > It reads NMOS Vth=1.76v, S-G-D mA=1.13 - whatever that means, I don't know > enough to interpret. > > Any off the cuff ideas? I have a replacement 2n7000 on the way, but still > wondering why it would fail in circuit, and if its really bad. > > Thanks, > Chip > AE5KA > __ 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] Sidetone has suddenly disappeared.
Nuts. Ill bet i inadvertantly changed the sidetone source, because i had been viewing the secondary menus just before. Overlooked sidetone source. Should have posted before pulling. I got this K2 second hand and have been trying to learn the ins and outs - there is a lot there. Thanks for your time Don! Chip On Thursday, July 28, 2011, Don Wilhelm wrote: > Chip, > > I suspect that you accidentally toggled the sidetone source in the menu. > If your K2 SN is 3000 or greater, or you have an earlier K2 with the > KPA100 or KIO2 added, you need to select U8-4 for the sidetone source. > If none of those conditions match, the sidetone source is U6-25. > > If you put Q5 back in the circuit, enter the menu for St L, hold EDIT to > edit the parameter, and first set the level at something reasonable - > between 20 and 40 - then tap the DISPLAY button to toggle the source. > When you hear sidetone, stop and exit the menu. > > To prevent future occurrences, I suggest that you do not set a PF key to > St L. When zero-beating, adjust the audio level on the signal (to match > the sidetone level) with the AF Gain control instead of adjusting the > level of the sidetone to match whatever signal level you have. > > 73, > Don W3FPR > __ 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] Sidetone has suddenly disappeared.
Chip, If you want to do a good job of learning the K2, go through the manual - you can skip the assembly parts because it is already assembled, but "walk through" the alignment and test parts. There is a lot of learning that a builder obtains in those sections that is not repeated anywhere else. You will not have to actually do the alignments, but just know that those steps are present. Then repeat that process for each of the installed options. If you do not have the manuals, you may download them from the Elecraft website. It would be nice if some enterprising K2 owner would write a comprehensive K2 Owner's Manual since many K2s now are not owned by those who have built one. Is there anyone out there up to the task? I simply do not have the time to do that. 73, Don W3FPR On 7/28/2011 10:00 AM, Chip Stratton wrote: > Nuts. Ill bet i inadvertantly changed the sidetone source, because i had > been viewing the secondary menus just before. Overlooked sidetone source. > Should have posted before pulling. I got this K2 second hand and have > been trying to learn the ins and outs - there is a lot there. > > Thanks for your time Don! > > Chip > > On Thursday, July 28, 2011, Don Wilhelm wrote: >> Chip, >> >> I suspect that you accidentally toggled the sidetone source in the menu. >> If your K2 SN is 3000 or greater, or you have an earlier K2 with the >> KPA100 or KIO2 added, you need to select U8-4 for the sidetone source. >> If none of those conditions match, the sidetone source is U6-25. >> >> If you put Q5 back in the circuit, enter the menu for St L, hold EDIT to >> edit the parameter, and first set the level at something reasonable - >> between 20 and 40 - then tap the DISPLAY button to toggle the source. >> When you hear sidetone, stop and exit the menu. >> >> To prevent future occurrences, I suggest that you do not set a PF key to >> St L. When zero-beating, adjust the audio level on the signal (to match >> the sidetone level) with the AF Gain control instead of adjusting the >> level of the sidetone to match whatever signal level you have. >> >> 73, >> Don W3FPR >> > __ > 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] Sidetone has suddenly disappeared.
The little manuals by Nifty are excellent. I have used both the K2 and K3 versions. These are about as "comprehensive" as necessary, as well as durable and "handy." http://www.niftyaccessories.com/Elecraft_RefGuide.htm John Ragle -- W1ZI = On 7/28/2011 10:32 AM, Don Wilhelm wrote: > It would be nice if some enterprising K2 owner would write a > comprehensive K2 Owner's Manual since many K2s now are not owned by > those who have built one. Is there anyone out there up to the task? I > simply do not have the time to do that. __ 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
