Hi, I have recently made a discovery during a routine checkup that my K3S draws *much* more TX current on 20 m than any of the other bands. Using Data A FSKD mode at the 100W level it draws about 22A versus 16-18 A on all other bands. DC voltage from the Powerwerx SS-30DV is 14.2V as measured at the binding posts. The K3S voltmeter indicates 14.2V in receive and 13.7V in transmit mode. Current is measured with the K3S built-in ammeter (~1A in receive). Power output is 100-102W as measured with an LP-100A on all bands 40m - 10m. TX IMD is not noticeably affected as measured using the built-in 2-tone generator. I measure maybe 33dB (5th order worst case) below PEP on 40m slowly worsening to 30dB on 10m, all within acceptable limits for a solid state 12VDC powered transmitter.
What's up with this? I don't know how long this has been been a "problem" as this is not something I routinely monitor. My much older K3 (with the old bipolar PA) does *not* exhibit this behavior. Is this indicative of a problem with the 20m low-pass filter perhaps? All measurements are done with a Ridge Electronics dummy load. All RF connections are tight and the LP-100A indicates 1.01 SWR on this dummy load in all cases. BTW my serial # is 10480, which is an early serial #. It was back to Elecraft twice in its first year for fixes to the transmit signal path to improve TX IMD. Knut - AB2TC PS. I am not worried about the electricity bill, but whether this is indicative of a potential future serious failure. -- Sent from: http://elecraft.365791.n2.nabble.com/ ______________________________________________________________ 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 Message delivered to [email protected]
