[Elecraft] [K2] KPA100 Temp Cal: Room temp or radio temp?
I may be wandering into nit-picky land, but I noticed using a hand held infrared thermometer that the heat sink of the KPA100 is usually about 2 degrees warmer than ambient air temperature (when the unit has been sitting idle for several hours). For example, the heat sink will measure about 26 degs C and the room air temp is about 24 degs C. For the purposes of the CAL tPA, which temp should I go with? Or does it really even matter? Secondarily, when I discovered all this, I also found out that I had never calibrated CAL tPA! I was wondering why the fan NEVER seemed to kick on! So, I've been using the KPA100 for YEARS without the benefit of the fan. I hope I didn't cause any long term degradation of the unit. Incidentally, it always seemed to get out at the proper power, but boy would it get hot! 73, Brian N5BCN -- View this message in context: http://elecraft.365791.n2.nabble.com/K2-KPA100-Temp-Cal-Room-temp-or-radio-temp-tp7613845.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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
[Elecraft] [K2] Tuning a magloop with KAT100
I've recently acquired a magloop that will be used with a K2/KPA100/KAT100 and I wanted to double check my tuning procedure. My plan was to tune the KAT100 into a dummy load (ATU in AUTO mode) and then place the ATU into SWR (x.x-1) mode. Then use the TUNE button on the K2 to tune the loop to resonance, then operate. Repeat for any band changes or when encountering significant SWR. Does this sound reasonable or am I missing a step or two? Brian, N5BCN -- View this message in context: http://elecraft.365791.n2.nabble.com/K2-Tuning-a-magloop-with-KAT100-tp7610957.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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
Re: [Elecraft] K2 - Unstable power output on 40m (digital modes)
Don, Yes, things settle down with a dummy load, so it looks like I'm dealing with RF feedback. Per the original post, I'm using an Elecraft BL2 balun at the coax/ladderline junction. Shouldn't this act as the common mode choke that you suggest or are you suggesting to place a common mode choke in addition to the balun? Interesting idea regarding the KPA100 latest version since 40m is the troublesome band. I purchased the KPA100 around 2011-2012, so I would think it has the latest hardware but I'll double check when I get a chance. 73 Brian, N5BCN -- View this message in context: http://elecraft.365791.n2.nabble.com/K2-Unstable-power-output-on-40m-digital-modes-tp7609533p7609539.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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
[Elecraft] K2 - Unstable power output on 40m (digital modes)
I'm having an issue with unstable power output using digital modes on 40m above about 20 watts. All other bands seem to be ok. My antenna setup is as follows: a loop consisting of about 245 feet of wire, feed line consists of about 21 feet of 450 ohm ladderline to an Elecraft BL2 balun, then about 3 feet of coax to KAT100/KPA100/K2. I've tried the balun in 1:1 and 4:1 configs with no apparent change. The feed point of the loop is in the attic above the shack, but the majority of the wire is outside running along a wood fence. No problems tuning any band including 40m. When using digital modes, power output and ALC action (no bars) appears normal on 10 through 30m, and even works ok on 80m. Haven't tried 160m. However, when attempting digital modes (using a Signalink) on 40m, power output and ALC action is "all over the place" and generally folds back to a couple of watts. The output also seems to be extremely "touchy" and sensitive to the TX drive setting on the Signalink that's not apparent on other bands. I don't see this craziness using a dummy load, so I'm suspecting maybe I'm getting RF feedback only on 40m for some reason. I'm not sure what to try to mitigate this. The variables I could change would be to increase/decrease the ladderline length, try a more robust balun, or maybe try a counterpoise wire tied to the balun's ground lug? Any ideas and suggestions would be most appreciated, I sure would like to be able to use 40m! 73 Brian, N5BCN -- View this message in context: http://elecraft.365791.n2.nabble.com/K2-Unstable-power-output-on-40m-digital-modes-tp7609533.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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
