K2 sidetone improvement
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I recently had a chance to implement the improved sidetone filter by TF3MA
(http://www.raunvis.hi.is/~matti/TF3MA/sidetone_tf3ma.html). This was inspired by the experience of KT5X in November (http://www.ac6rm.net/mailarchive/html/elecraft-list/2006-11/msg00456.html). This mod really works wonders with the sidetone quality of the K2, and makes it much more like actually received high quality CW. It is probably the mod which has made the most immediate audible difference in my K2 of all the mods that I have made over the years - and I have made many! It is also really very simple to do. The explanation is that it is a better engineering solution to harmonic filtering than the present filter, and that applies even in comparison to the improved filter in the serial no 3000+ K2's. 73 Sverre LA3ZA http://www.qslnet.de/la3za/ -- Jeg bruker gratisversjonen av SPAMfighter for privatbrukere. Den har fjernet 5744 soppelpostmeldinger til na. Betalende brukere har ikke denne meldingen i e-postene sine. Fa tak i SPAMfighter gratis her: http://www.spamfighter.com/pro _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
I changed K2 R98 to 1K - not good?
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My K2/100 shows a lot of variation in TX output, esp. on 40 meters. I'll set it for 50 watts and the power will toggle up and down by 10's of watts. Time to change R98.
Checking old posts, I see that values of 1.1 KOhm seem to be good, I have a 1K resistor so I put that in. Put the rig back together and ... Max output on 40 meters is about 3 watts. It is lower below and above 40 and on 20 or above there is no output. Hmmm, did I do bad? My next step will be to parallel another R with R98 so I can drop the resistance and see if I regain some power. Sheesh, and this is on the eve of SKN too. What a bad time for my rig to be down. - Keith N1AS - - K2 5411.ssb.100 - _______________________________________________ Elecraft mailing list Post to: [hidden email] 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: I changed K2 R98 to 1K - not good?
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Kieth,
The proper procedure is to temporarily use a pot in place of R98 to determine the maximum value your K2 can tolerate without loss of power (especially on 10 meters). Then measure the pot and replace R98 with the next lower standard value. The internal gain of each K2 is a bit different, so the proper value must be determined emperically for each K2. 73, Don W3FPR > -----Original Message----- > > My K2/100 shows a lot of variation in TX output, esp. on 40 > meters. I'll set it for 50 watts and the power will toggle up > and down by 10's of watts. Time to change R98. > > Checking old posts, I see that values of 1.1 KOhm seem to be > good, I have a 1K resistor so I put that in. Put the rig back > together and ... > > Max output on 40 meters is about 3 watts. It is lower below and > above 40 and on 20 or above there is no output. Hmmm, did I do bad? > > My next step will be to parallel another R with R98 so I can drop > the resistance and see if I regain some power. > > No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.16.1/611 - Release Date: 12/31/2006 12:47 PM _______________________________________________ Elecraft mailing list Post to: [hidden email] 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: I changed K2 R98 to 1K - not good?
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In reply to this post by Darwin, Keith
I'll bet you find out that the 1 K you put in was actually some other value
.. or .. something happened you did not plan (cold solder joint?). If the value of 1K is too high for your particular K2/100 the output will not reach full ratings on some bands but it will still be a lot higher than 0 or 1 ! Yep, use a pot or just patch in various fixed resistors like I did. I also tested the value of the fixed resistor I was inserting just to make sure it was what I thought it was. Don K7FJ ----- Original Message ----- From: "Darwin, Keith" <[hidden email]> To: <[hidden email]> Sent: Sunday, December 31, 2006 3:25 PM Subject: [Elecraft] I changed K2 R98 to 1K - not good? My K2/100 shows a lot of variation in TX output, esp. on 40 meters. I'll set it for 50 watts and the power will toggle up and down by 10's of watts. Time to change R98. Checking old posts, I see that values of 1.1 KOhm seem to be good, I have a 1K resistor so I put that in. Put the rig back together and ... Max output on 40 meters is about 3 watts. It is lower below and above 40 and on 20 or above there is no output. Hmmm, did I do bad? My next step will be to parallel another R with R98 so I can drop the resistance and see if I regain some power. Sheesh, and this is on the eve of SKN too. What a bad time for my rig to be down. - Keith N1AS - - K2 5411.ssb.100 - _______________________________________________ Elecraft mailing list Post to: [hidden email] 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: [hidden email] 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: I changed K2 R98 to 1K - not good?
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Don, you are right on the money!
The resistor I put in was 10K, not 1K! Ahhhggg! I went back and tried a 1K. Now i get very stable full output on all bands. 10 Meters is giving 95 watts into a dummy load. That's plenty. Now, back to special event station K1Y SKN operations ... - Keith N1AS - - k2 5411.ssb.100 - ________________________________ From: Don [mailto:[hidden email]] I'll bet you find out that the 1 K you put in was actually some other value .. or .. something happened you did not plan (cold solder joint?). If the _______________________________________________ Elecraft mailing list Post to: [hidden email] 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: I changed K2 R98 to 1K - not good?
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Well, I have had the experience! Sometimes the orange band looks a lot
like a red band ... and I have seen 'brown' bands that were really a dark red. I let the smoke out of one of those once. Don K7FJ --------------------------------------- Don, you are right on the money! The resistor I put in was 10K, not 1K! Ahhhggg! I went back and tried a 1K. Now i get very stable full output on all bands. 10 Meters is giving 95 watts into a dummy load. That's plenty. Now, back to special event station K1Y SKN operations ... - Keith N1AS - - k2 5411.ssb.100 - ________________________________ From: Don [mailto:[hidden email]] I'll bet you find out that the 1 K you put in was actually some other value .. or .. something happened you did not plan (cold solder joint?). If the _______________________________________________ Elecraft mailing list Post to: [hidden email] 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: [hidden email] 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 |
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In reply to this post by Darwin, Keith
That's why I always check the value with an ohm meter if there is any ambiguity in reading the color code.
Doug W6JD -------------- Original message -------------- From: "Don" <[hidden email]> > Well, I have had the experience! Sometimes the orange band looks a lot > like a red band ... and I have seen 'brown' bands that were really a dark > red. I let the smoke out of one of those once. > > Don K7FJ > --------------------------------------- > > Don, you are right on the money! > > The resistor I put in was 10K, not 1K! Ahhhggg! > > I went back and tried a 1K. Now i get very stable full output on all bands. > 10 Meters is giving 95 watts into a dummy load. That's plenty. > > Now, back to special event station K1Y SKN operations ... > > - Keith N1AS - > - k2 5411.ssb.100 - > > ________________________________ > > From: Don [mailto:[hidden email]] > > > I'll bet you find out that the 1 K you put in was actually some other value > .. or .. something happened you did not plan (cold solder joint?). If the > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > 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: [hidden email] > 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: [hidden email] 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: I changed K2 R98 to 1K - not good?
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But I DID check it with an ohmmeter. I don't know the color codes so I
use the meter in cases like this. I guess I need to learn that 9.9 KOhm is NOT the same as 0.99 KOhm :-) The problem was I knew the part was a 1K even before I checked it. Having already made up my mind that it was a 1K resistor, my brain avoided confusion by ignoring the evidence. Fortunately the fix was easy and the rig worked flawlessly for me through SKN. - Keith N1AS - - K2 5411.ssb.100 - -----Original Message----- From: Doug [hidden email] That's why I always check the value with an ohm meter if there is any ambiguity in reading the color code. -------------- Original message -------------- From: "Don" <[hidden email]> > Well, I have had the experience! Sometimes the orange band looks a lot > like a red band ... and I have seen 'brown' bands that were really a > dark red. I let the smoke out of one of those once. > > Don K7FJ _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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