Your idea of hum coming from higher current sounds plausible here, Bill. You didn't say what your K2/100 is actually drawing but, yes, mine draw more current on 160 and 80 than on most other bands.
I plugged in a dummy load and here's what mine requires at 100 watts on each band: 160m = 17.5 amps 80m = 17 amps 40m = 14 amps 30m = 15 amps 20m = 14.5 amps 17m = 17 amps 15m = 17.5 amps 10m = 15 amps That's total current reported by my Astron power supply. Ron AC7AC -----Original Message----- During a recent contest, I received a report of poor signal quality on my CW signal on 80m. I've run some tests and find that on 80m and 160m, there's a distinct hum on the signal when running over about 80 watts. I've also noticed that the current used seems to jump in discrete steps as I increase the power level. It could be that this hum is present on the power supply at higher current levels. On 160m, the rig pegs the scale on my power supply ammeter when running full power. Do the current requirements of the KPA100 increase on these bands? And what would cause the discrete steps in current consumption at the higher power levels? We're talking a jump in current about every 10 watts or so. Prior to the contest, I performed the KPA100 modifications for high SWR operation and installed the new firmware. I've noticed that the heat sink is running noticeably hotter than before. This while transmitting into a 50 ohm dummy load. Any suggestions would be appreciated. The rig appears to operate just fine, I'm just a little concerned about the signal quality and the extra heat. Bill Coleman, AA4LR, PP-ASEL Mail: [EMAIL PROTECTED] Quote: "Not within a thousand years will man ever fly!" _______________________________________________ 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
