Don, I have checked what you advised. But envrything looks fine. I don't believe that Q9 itself is something wromg.
Thank you, Hideki JF1KGX ----- Original Message ----- From: "Don Wilhelm" <[email protected]> To: "JF1KGX" <[email protected]> Cc: <[email protected]> Sent: Wednesday, July 29, 2009 6:47 AM Subject: Re: [Elecraft] K2/KPA100: External Amplifier Keying Test (PA Key) Problem > Hideki, > > With power off, check the resistance from the source of Q9 to ground. If > you can check from the lead of Q9 rather than the solder connection. If > it is not zero ohms, you have a soldering problem there. > > If the source of Q9 is well grounded, next check the voltage at the Q9 > gate during TUNE - it should be in the 3 to 5 volt range. - if lower than > that, check the soldering and value of R1 and the soldering at U1 pin 16 > (pin 16 of U1 should be very near 5 volts during TUNE). > > If all is good with those checks, Q9 itself is the prime suspect (but I > have never hear of one being a problem). > > 73, > Don W3FPR > > JF1KGX wrote: >> Somebody has asked the same before. But nothing has been replied. >> Now I have the same problem. >> >> Page 49 of the KPA100 instructions calls for testing the resistance >> between >> ground and the tab of Q9 on the KPA100 board (or center conductor of the >> PA KEY >> output jack, J7). >> >> According to the instructions, the resistance should drop to less than 3 >> ohms >> when the K2 is put into TUNE mode. Mine only drops to about 270 ohms. >> The >> troubleshooting in the KPA100 manual doesn't even include any information >> for >> what to do if the resistance doesn't drop to less than 3 ohms. >> >> So far everything else seems to be working correctly with the KPA100. >> My serial number is 06617. >> >> Please advise me. >> >> Thanks >> >> Hideki >> JF1KGX >> >> >> ______________________________________________________________ >> 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 >> ------------------------------------------------------------------------ >> >> >> No virus found in this incoming message. >> Checked by AVG - www.avg.com Version: 8.5.392 / Virus Database: >> 270.13.34/2268 - Release Date: 07/28/09 06:00:00 >> >> > ______________________________________________________________ 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
