That is odd, Ben. Any band-specific power change is usually associated with the bandpass filters for that band. Ten meters could be an exception because the K2 transmit chain has the lowest gain at that band, so if something is reducing your overall power output, it might only cause you to fail to meet specs on that one band. Are you getting the amount of power you've previously had on the other bands at full power output? If so then it is a 10-meter-only situation.
If that's the case, I'd look very closely at all the BPF components associated with 10 meters, including the relay pins, for a missed or poor solder joint. Sometimes a bad joint doesn't show up for years, depending upon the environment in which it's used. Then, as oxidation starts to find its way into the space where the unsoldered lead touches the pad, things start changing. Ron AC7AC -----Original Message----- When I first built K2 #4429 in the fall of '04 I was very careful with the winding/installation of T2 (following the App note on the Elecraft web site) in order to get full 10w out on 10m. My recollection is that I was able to get at least 10w at 28.0 MHz, and like 9.8w at 28.8 MHz, which I could live with, and made no further changes. This week I was performing the power control mod (R98) and noticed that I was only getting a maximum of 7.5w at 28.8 MHz. While performing this mod, I had my completed, but un-installed KPA100 in line, and I thought maybe there was a difference in power output measurement between the base K2 and the K2/100, so I completely disconnected the KPA100, and replaced R98 with the original resistor to re-measure output on 28.8 MHz, getting again 7.5w or so. The only changes I've made since my original build/alignment is the addition of a K6XX/N0SS zero beat indicator, addition of the K160RX module, addition of 1 capacitor in VCO area to bring VCO voltages into correct ranges after the addition of K160RX, and the addition of the RF/12V connectors for the KPA100. I wonder what might have changed to lower the 10m output? -Ben K1NT _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
