Pat, Something strange is happening here. First the facts of 'the case': 1) The KPA100 wattmeter should not be frequency dependent, and neither should your external wattmeter if it is functioning correctly. 2) Your KPA100 wattmeter apparently needs to be calibrated - use a good 50 ohm resistive dummy load and start over at the point where you adjust the trimmer cap - caution, a dummy load that is reactive will give you an incorrect indication of the null point. 3) If you use your external wattmeter to set the KPA100 forward power level, then the K2/100 indication should track with that external wattmeter afterwards. 4) Be aware that an external wattmeter may be in error by as much as 10 or 20% OF THE FULL SCALE READING! This is the typical spec for wattmeters. Be careful of the scale, on a 100 watt scale, that means that the error could be as large as 20 watts (at any point on the scale), so do not use a 100 watt scale to read a 20 watt level, use a 20 watt scale where the maximum error is only 4 watts. I cannot stress this subtle point strongly enough. Even a Bird wattmeter is speced at 5% of full scale, and that is only guaranteed after calibration!
You may have something else wrong there too, but as first steps, check the components in the wattmeter section and re-do the wattmeter calibration. Then see if the power control becomes proper. 73, Don W3FPR > -----Original Message----- > > If it happens on all bands, then you have another problem, so > ask again and > > provide more information and we can lead you on a path of > 'problem chasing'. > > First you will have to tell us whether the 'wattmeter' you > refer to is an > > external wattmeter or the internal K2 indication. > > > > Both. Happens on all bands. Relative to an external wattmeter the power > the K2 shows is wrong and the power the KPA100 outputs in some > cases is not > ok. Max out on the lowbands is almost 150 watts and pulled > current is above > 20 amps. On 20m and above output is more normal, output is never above > 100w. For example the K2 reads 80, but the external wattmeter reads 100w. > On 15m output is below normal. The K2 will read 110 and the max > out is 90w. > Approachs normal at around 70w. On 10m ouptput tracks like 20m except max > out is about 110w. > > > Pat N8vw > _______________________________________________ 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
