Hey ! I’ve soldered a 20pF capacitor that i’d from personal stock between U4 pin 1 and U4 pin 12 (ground), and all is good !
I can go to BFO Test without any problem ! Does this mod could be considered as definitive or should I change Q19 with another J310 ? Thanks a lot for the super hyper quick help! :-) Best regards. — Chris > Le 6 mai 2020 à 23:37, Don Wilhelm <donw...@embarqmail.com> a écrit : > > Chris, > > Your English is much better than my French! I hope you can understand the > following: > > You have a Q19 that is not willing to work at the high frequency end of the > PLL range. > > The proper thing to do is replace Q19 with a J310 FET that is better. Order > one from Elecraft (email to supp...@elecraft.com) with the part number. > > What you can try is to add a small value capacitor (12 or 15pF) from U4 pin 1 > to U4 pin 12 (ground) to see if that restores proper function. If you do not > have a stock of small capacitors, use the 12pF in the K2 kit which you have > not yet installed and order a replacement from Elecraft. > > Proper functioning thru-hole J310s have been a problem since Elecraft ran out > of the old ones and found that they had been discontinued by the manufacturer. > > I know of one ham in Europe who used an SMD J310 as a replacement - but if > you consider that, know that the basing is not the same and you would have to > go from the data sheet to know which pin to connect to the holes. He mounted > it on the bottom of the board. > > 73, > Don W3FPR > >> On 5/6/2020 4:44 PM, Christophe GIBERT wrote: >> Hi! First of all, sorry for my poor english, i’m french ;-) >> I’m building my k2 number 7855. >> In the first step of the 4mhz oscillator calibration, i get a frequency of >> 00500.00 instead of 12090.00 >> When i press BAND + : 00475.00 and BAND - : 12085.43 (stable). >> I’ve tested probe on TP2, I’d 4913.52 >> I reviewed all components in the pll schematics and nothing seems wrong. >> Please help me, i don’t know what to look for now. >> Thanks a lot. >> — >> Chris >> ______________________________________________________________ >> 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 >> Message delivered to donw...@embarqmail.com ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
