S meter
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I just completed K2 #05671--No I haven't been working on it for 14 months, I
bought the kit unopened from a friend who never got up to urge to build it. The only problem I have is No S meter. The receiver seems to work normally, sensitivity is equal to my other K2. AGC seems to work normally, AGC threshold is set at 3.8 Volts. CAL S LO works fine, but CAL S HI does not. With the RF gain fully ccw the S meter will not light at all. I have tried it with the meter set in both DOT and BAR. Now get this, at the end of PART II Alignment, CAL S HI did work. Something messed it up during final construction. FWIW the Bar Display DOES work in transmit showing RF/ALC so its not burned out and the first segment comes on in CAL S LO. Any suggestions as to where to look next? Does anybody know if Elecraft is working on Dec 31? 73 James Quinn kc4ee _______________________________________________ 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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James,
I have to take you at your word that the AGC is working OK. If that is in fact true and you cannot get good S-meter indications on the bargraph, the only thing that could be wrong is th esoldering of pins 9 and 10 of RP6 or the soldering of U6 pin 3 (all on the Control Board). Check those first. Should that not be the problem, then more extensive checks of the AGC circuit are in order, and you can also conclude that your AGC is *not* working properly. Remember that the most common cause of kit problems is soldering problems. When in doubt, check the soldering, then recheck the soldering. When you have finished that, check the soldering. 73, Don W3FPR JC Quinn wrote: > With the RF gain fully ccw the S meter will not light at all. I have > tried it with the meter set in both DOT and BAR. Now get this, at the > end of PART II Alignment, CAL S HI did work. Something messed it up > during final construction. FWIW the Bar Display DOES work in transmit > showing RF/ALC so its not burned out and the first segment comes on in > CAL S LO. Any suggestions as to where to look next? Does anybody > know if Elecraft is working on Dec 31? > 73 > James Quinn kc4ee > 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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Wow! Don, you're good! I had looked at those pins under 5x magnification
and they looked fine. I reflowed those pins and a couple of more on the board that did look questionable and now she works fine! 73 and Thanks a Million! James ----- Original Message ----- From: "Don Wilhelm" <[hidden email]> To: "JC Quinn" <[hidden email]> Cc: <[hidden email]> Sent: Sunday, December 30, 2007 6:21 PM Subject: Re: [Elecraft] S meter > James, > > I have to take you at your word that the AGC is working OK. If that is in > fact true and you cannot get good S-meter indications on the bargraph, the > only thing that could be wrong is th esoldering of pins 9 and 10 of RP6 or > the soldering of U6 pin 3 (all on the Control Board). Check those first. > > Should that not be the problem, then more extensive checks of the AGC > circuit are in order, and you can also conclude that your AGC is *not* > working properly. > > Remember that the most common cause of kit problems is soldering problems. > When in doubt, check the soldering, then recheck the soldering. When you > have finished that, check the soldering. > > 73, > Don W3FPR > > JC Quinn wrote: >> With the RF gain fully ccw the S meter will not light at all. I have >> tried it with the meter set in both DOT and BAR. Now get this, at the >> end of PART II Alignment, CAL S HI did work. Something messed it up >> during final construction. FWIW the Bar Display DOES work in transmit >> showing RF/ALC so its not burned out and the first segment comes on in >> CAL S LO. Any suggestions as to where to look next? Does anybody know >> if Elecraft is working on Dec 31? >> 73 >> James Quinn kc4ee >> > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: > 269.17.12/1203 - Release Date: 12/30/2007 11:27 AM > > _______________________________________________ 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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James,
Well, maybe not that good - just a little application of logic aided by a look at the schematic. Couple that with the facts that the design is known to work and the most common cause of failure is the soldering. Have a good day and an Happy New Year. 73, Don W3FPR JC Quinn wrote: > Wow! Don, you're good! I had looked at those pins under 5x > magnification and they looked fine. I reflowed those pins and a > couple of more on the board that did look questionable and now she > works fine! > 73 and Thanks a Million! > James > ----- Original Message ----- From: "Don Wilhelm" <[hidden email]> > To: "JC Quinn" <[hidden email]> > Cc: <[hidden email]> > Sent: Sunday, December 30, 2007 6:21 PM > Subject: Re: [Elecraft] S meter > > >> James, >> >> I have to take you at your word that the AGC is working OK. If that >> is in fact true and you cannot get good S-meter indications on the >> bargraph, the only thing that could be wrong is th esoldering of pins >> 9 and 10 of RP6 or the soldering of U6 pin 3 (all on the Control >> Board). Check those first. >> >> Should that not be the problem, then more extensive checks of the AGC >> circuit are in order, and you can also conclude that your AGC is >> *not* working properly. >> >> Remember that the most common cause of kit problems is soldering >> problems. When in doubt, check the soldering, then recheck the >> soldering. When you have finished that, check the soldering. >> >> 73, >> Don W3FPR >> >> JC Quinn wrote: >>> With the RF gain fully ccw the S meter will not light at all. I >>> have tried it with the meter set in both DOT and BAR. Now get this, >>> at the end of PART II Alignment, CAL S HI did work. Something >>> messed it up during final construction. FWIW the Bar Display DOES >>> work in transmit showing RF/ALC so its not burned out and the first >>> segment comes on in CAL S LO. Any suggestions as to where to look >>> next? Does anybody know if Elecraft is working on Dec 31? >>> 73 >>> James Quinn kc4ee >>> >> >> >> >> -- >> No virus found in this incoming message. >> Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: >> 269.17.12/1203 - Release Date: 12/30/2007 11:27 AM >> >> > > > 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 JC Quinn
James and all,
Someone on this reflector commented some time ago that solder connections should look like mountains, but not look like volcanoes. A good solder connection will look like a mountain with a concave surface where the solder edge is nearly invisible - the solder should flow to a very thin edge on both the component lead and the solder pad. If the edge is quite noticeable, insufficient heat was applied to the connection. If the solder fillet surface is convex, too much solder was applied, and that can mask a poor solder connection. If the solder looks like a 'ball' on the component lead, that is a combination of too much solder and inadequate heat. Look critically at your soldering and compare the results with the diagrams in the soldering tutorial on the Elecraft website. If the soldering is not up to par, functions can work initially, but fail later (up to 2 years or more) after a bit of oxidation sets in and makes a marginal solder connection a problem. In case of trouble, check the soldering, then re-check the soldering, and when you have completed that - check the soldering. 73, Don W3FPR JC Quinn wrote: > Wow! Don, you're good! I had looked at those pins under 5x > magnification and they looked fine. I reflowed those pins and a > couple of more on the board that did look questionable and now she > works fine! > 73 and Thanks a Million! > James > _______________________________________________ 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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