OK, I removed D16 and D17, and on the diode setting of my DVM, they both measured the same value both forward and backward - 034. Which means they were totally shorted.
I replaced them with new diodes (which measured 316 forward, and infinite backward), and the RF display is once again working. Unfortunately, I don’t have a dummy load to do the calibration on page 48 right now, so it will probably have to wait a few more days before I can everything in the same place. However, I’m declaring this mystery solved. I am very glad I put machined socket pins in for D16 & D17. Took only a couple of minutes to replace them. > On May 15, 2019, at 7:30 PM, Bill Coleman <[email protected]> wrote: > > Took me over week to check this, but power is the same whether Tune or > Tune/Display — 100 watts! > > So, the suspects are likely D16 & D17. > > Fortunately, the last time I replaced them I put in a couple of pins from a > machined pin socket, so it should be an easy job. > > I’ve had to replace U6 before as well. I think I have a socket there, too. > >> On May 4, 2019, at 12:11 AM, Don Wilhelm <[email protected]> wrote: >> >> Bill, >> >> Set the power at 50 watts and do a TUNE. >> Is the output power at 20 to 25 watts? If so, so far so good. >> Now try a TUNE/DISPLAY (hold both buttons at once). Is the power near 50 >> watts? If so, you have proper power control and the problem is with the LED >> display. >> >> OTOH, if the actual power in both cases above goes to 100 watts or more, >> then the first step is to replace KPA100 D16 and D17. If that does not fix >> things, there is likely another problem in the KPA100 wattmeter, likely >> KPA100 U6 - but get back with the information before replacing it, there are >> more tests to verify or deny that possibility. >> >> 73, >> Don W3FPR >> >> On 5/3/2019 10:25 PM, Bill Coleman wrote: >>> I’ve recently seem a problem with my K2/100. It transmits ok, and the power >>> level out tracks the power control, but the power indication LEDs remain at >>> zero. >>> No, I’m not in ALC mode, I’m definitely in RF mode for the meter. >>> I’m using an external wattmeter (a Kenwood AT-250 in passthrough mode), and >>> can definitely see 100 watts being transmitted. >>> I’m thinking that maybe D16 and D17 may have been fried. Is that a good >>> guess? > > Bill Coleman, AA4LR, PP-ASEL Mail: [email protected] > Web: http://boringhamradiopart.blogspot.com > Quote: "Not within a thousand years will man ever fly!" > -- Wilbur Wright, 1901 > > ______________________________________________________________ > 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 Bill Coleman, AA4LR, PP-ASEL Mail: [email protected] Web: http://boringhamradiopart.blogspot.com Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901 ______________________________________________________________ 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
