Hi, This radio has been problem free. (And a heck of a lot of fun!!!)
I've never recalibrated anything, as per the manual, there has been no need. I have done FW upgrade at least once and that is currently 02.38/01.37. Just started getting "ERR TXG" on 50 MHz. Have seen several values in the D=xxx message as well. Manual has: ----- Error msg: ERR TX Problem: Transmit gain constant out of range Troubleshooting steps: If this only occurs on one or two bands, there could be a problem with a band-pass or low-pass filter. Also try re-doing Transmit Gain calibration (pg. 33). ----- Did some bench testing with a dummy load. I checked and problem only occurs on 50 MHz. Suspect degradation. Would be nice to resolve before the June VHF! :-) Did not try redoing the transmit gain calibration, as the troubleshooting steps suggests otherwise. With tech support, got as far as the suggestion of reducing power supply sag. Did have some IR drop, especially on 50 MHz, so swapped for lower IR drop power supply cable. Confirmed bench supply itself isn't sagging. So, what I measure now: At 28 MHz RX mode measures 13.60 V on DMM (on outside of DC coaxial power plug), 13.8 V on KX3 meter, and 0.17 A on KX3 meter. At 28 MHz TX constant 4 W carrier measures 13.55 V on DMM (on outside of DC coaxial power plug), 13.4 V on KX3 meter, 2.18 A on KX3 meter and 1.2 to 1 VSWR on KX3 meter. At 50 MHz RX mode measures 13.60 V on DMM, 13.8 V on KX3, 0.19 A on KX3. At 50 MHz TX constant 4 W carrier measures 13.53 V on DMM, 13.3 V on KX3, 2.9 A on KX3 and 1.6 to 1 VSWR on KX3 meter. VSWR is better of course below 28 MHz. (Microwave dummy load.) Of course, I don't have baseline measurements from when I first received the radio to compare against. If anyone can make similar measurements of their KX3 for comparison, that would be very interesting. Want to know about TX current draw and the 1.6 to 1 VSWR. Manual specs "1 to 2 A typical in transmit". Current is on the high side of that at 28 MHz even with the power backoff. 3A on 50 MHz, though? And, yes, the PA temp climbs quite quickly. Needs to go in for repair? No problem with that if that's the thing to do. (Schedule is probably too tight for June VHF, and I'm sure the stay at home order doesn't help.) I can do some trouble shooting and component swap here, no problem. My biggest limitations are time (work seems even busier with stay at home) and lack of a body of knowledge regarding this specific radio. I haven't popped it open for visual inspection, yet. Probably should do that especially around the 6m filters and the active and electromechanical RF switches. If I don't have a backup rig, I'm either not a serious contester, or i'm wating for a K4. Not sure. :-) Again, this radio has been a ton of fun! A little sad to run into my first problem with it, but it's a field radio, and I don't expect miracles. Thanks in advance, Drew n7da San Diego ______________________________________________________________ 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
