Thanks to those who contacted me. Nobody seems to have a Rev B Schematic! The possibility of an exchange unit has not materialised so as the KPA3 is still mine, I decided a bit of disassembly was in order before taking it to be serviced.
Findings upon removal for testing: C43 and C44 passed testing with a Peak LCR45 - refitted R27 OK - refitted D7,8 & 9 OK with Peak DCA75 - replaced since I could get these and they are very cheap D10 Pin Diode tested as ‘no component’ with Peak DCA75 and multimeter shows open circuit The MA4P4006B-402 600V Pin Diode does not appear to be available for sale in the UK, but I am checking with the service centre. Conclusions: One fault found, need to repair that before further testing. Since I do not know the history of the unit, which was a Silent Key sale, there is no information about the likely cause of this failure. Many thanks once again - I will post the final outcome on the reflector, once all is working again. 73, Ted G7BQM > On 23 Feb 2019, at 12:14, Ted G7BQM <[email protected]> wrote: > > Hello All, > > I have recently acquired an early K3 which needs tidying and checking over. > So far all appears to be OK except for the KPA3 which gives no RF output but > the rig draws 14 Amps regardless of the power setting. The LPA is working > fine with up to 12 W RF out and a max current draw of 4 A. > > Visual checking of the KPA3 board reveals nothing amiss but also shows > considerable component differences compared to the only schematic I could > find on the Elecraft website - the Rev C version. > > If any of you early adopters have a .PDF schematic for the KPA3 Rev B, I > would be most grateful for an electronic copy. > > 73, Ted G7BQM (with quite a lot of Elecraft stuff!) > > > > > ______________________________________________________________ > 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 > ______________________________________________________________ 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
