Don, Thanks again. I had one question from your last email. Did you mean C60? I couldn't find C50 in the VFO circuit. I shorted C60 which put the drain to ground. Still no help. The BFO is working though, so that's good news. I also checked D13 and D8. They match the outline on the board, so they should be good. I will try again tomorrow when I've had some rest. Sometimes I've found fresh eyes help me see things I missed the night before.
Joseph On Tuesday, April 29, 2014 9:15 PM, Don Wilhelm-4 [via Elecraft] <[email protected]> wrote: Joseph, See if the VFO is oscillating. Check the internal counter probe by plugging it into TP2 and use menu CAL FCTR - you should see a frequency near 4913 kHz (the BFO frequency). If that is good, the counter probe should be working. Then plug the probe into TP1. The frequency should be near the K2 dial frequency plus 4913 kHz. If you see that frequency, all is OK with the VFO. If you instead see all zeros, the VFO is not oscillating, and you will have to figure out why. You have already checked the winding of T5, so there may be something else. Check the orientation of D13 and D8 as starters. Then eliminate the VFO ALC from the picture by placing a short from the drsin og Q17 to ground (a convenient place to do that is to put a temporary solder bridge across the leads of C50). Do you get a VFO frequency reading with that in place? If so check the soldering of the VFO ALC components. Look on the schematic and find on sheet 1 for the RF Board all the components in the area labeled VFO ALC and check the soldering of all those components - remove the solder bridge from C50 and see if it still oscillates. If it does, you should be on your way to success. 73, Don W3FPR On 4/29/2014 9:13 PM, Joseph Baxley via Elecraft wrote: > Don, Matt, > > I looked at the transformer and have double checked him. I saw that there > was electrical continuity between leads 1 & 2 and 3 & 4 (i.e. zero Ohm > resistance between said leads). Also, 3 & 4 are the green leads. I checked > that the green wires weren't crossing and that they were spaced each turn > between the red wires. I did notice that they weren't exactly centered, > with more red turns before lead three than after lead four. I pulled the > transformer out and rewound the green wires to center them and see if it > helped any. No dice. Also I checked the number of turns, 16 red and 4 > green. I'm intimately familiar with not having properly stripped the wires. > That was a problem building my K1! > > I'm fairly certain then that the transformer is not the problem. I've been > checking things like the diodes that run through the VCO to make sure that I > have not put in one backwards. I've also been looking for cold joints or > solder bridges. Haven't found one yet. > > Thanks, > Joseph > > > > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/K2-VCO-Not-Oscillating-tp7588086p7588156.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ________________________________ If you reply to this email, your message will be added to the discussion below:http://elecraft.365791.n2.nabble.com/K2-VCO-Not-Oscillating-tp7588086p7588159.html To unsubscribe from [K2] VCO Not Oscillating, click here. NAML -- View this message in context: http://elecraft.365791.n2.nabble.com/K2-VCO-Not-Oscillating-tp7588086p7588160.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
