Hi, I had a similar problem last year in ARRL SS where the power output jumped around. Gary suggested doing the power calibration again. I had little trouble getting it done in the Utility but doing it manually got things settled down again. I'm not sure that this fixed whatever the problem was (why did the calibration have to be done again) but it fixed the symptoms as it hasn't done it again. Well maybe it did it a bit once or twice at C6AKX this year. Dunno. Try it. 73, Fred KE7X
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Igor Kosvin Sent: Monday, January 03, 2011 4:24 PM To: 'Kok Chen' Cc: [email protected] Subject: Re: [Elecraft] Curious phenomenon with doublet on 80m Hi Chen, I did connect dummy load tonight. With the dummy load the SWR at the problematic region is fine, but I see different symptom. When I activate tune everywhere else I see on the display: top line "1.0-1", bottom line "30 W". Which corresponds to my tuning power. Both lines are stable and the power meter shows accurate 30W or so. At the problematic region the top line alternates between "1.0-1" and "--" and the bottom line reading is very unstable - the power jumps randomly from 18W to 48W, so is the reading of wattmeter - it is also unstable. The returned power stays pretty low though. The meter bars on K3 also unstable. The SWR shows one bar and it is blinking fast. The RF is jumping randomly. I do not have presently neither VNA nor Antenna Analyzer. I guess though that use of dummy load pretty much exonerates antenna or tuner. The dummy load is just one big resistor with very low reactance. 73, Igor, N1YX -----Original Message----- From: Kok Chen [mailto:[email protected]] Sent: Monday, January 03, 2011 2:02 AM To: Igor Kosvin Subject: Re: [Elecraft] Curious phenomenon with doublet on 80m Hi Igor, You are correct that you should try to see if the K3 will work properly into a dummy load at 3504 kHz. Do you have an Antenna Analyzer or VNA? If so, I would suggest tuning the MFJ to match the Kenwood rigs, then remove the rigs from the tuner and use to antenna analyzer to look into the MFJ's Tx connector instead of connecting the K3. The impedance that you read on the analyzer might give a clue as to why the K3 can't work into it. Vy 73 Chen, W7AY ______________________________________________________________ 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
