Joseph, Since you have a good frequency reading at TP3, the PLL Reference Oscillator is working, and the problem is in the area of Q18. So we move the problem area on the schematic to the upper right corner of the RF Board schematic sheet 1. Note that the VFO output goes through U3 before it gets to TP1, so try reading the VFO frequency at U3 pin 3. If you have a good reading there (reading should be 4915 kHz higher than the frequency displayed on the K2 dial for all bands below 15 meters).
Since it worked once, the most likely problem is soldering, so re-flow the connections with a hot (750 deg F) iron. There is a possibility that Q17 was damaged by static during construction and failed later. As a test, short Q17 drain to its source and see if the VFO starts oscillating (you can accomplish the same thing by temporarily shorting lead #3 of T5 to ground). Count the turns on T5 carefully and look critically at the soldering of the T5 leads. If there is a visible ring around the lead, it was not well tinned - it has been said that solder connections should look like mountains, but *not* volcanoes, and that is an apt description of the condition I am referring to. The same thing applies to all solder connections, not just toroid leads. The solder should flow out on both the solder pad and the component lead to an almost invisible edge. If the solder looks more like a ball than a nice smooth fillet, it is likely that the connection did not receive enough heat. If there is too much solder, use solder wick to remove some of it. With thru-plated holes on the boards, the amount of solder required is only enough to fill the hole, although I like to see a very small fillet too. Neither the board or the component will be damaged with normal soldering temperatures maintained for up to 5 or 10 seconds, although you should use an iron temperature that produces a good solder connection in 2 to 3 seconds. If it takes longer than that, the iron is too cold, and if the solder flows in less than 2 seconds, the iron is too hot. Watch for the solder to *flow*, not merely to melt. 73, Don W3FPR Foxjazz wrote: > Hello Don, > > Don, the call was in the subject line. > > Sorry for the confusion. I had the pll circuit working great with all > alignments before starting on phase 3 and putting the ssb board in. > > As far as checking parts, the parts were correct when I checked them > the second time, and the pll circuit was working. > > tp3 reads within tolerance. Unfortunately I broke the agc gain > transistor handling the control board, so have to replace. But that > shouldn't affect my issue. > > I was doing some voltage readings and found an issue on u5 on the rf > board. pin 1 was 5 volts. > > U6: pin 5 was 4v on and 8 was 8 volts. > > tp3 reads good, and checked good. However sometimes it feels as if it > doesn't check good because the band - doesn't keep the freq down on > occasions. > > N0XDB > ______________________________________________________________ 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
