Chuck, Look at the Low Pass Filter. The PA transistor cannot really go to 10 watts output - I suspect the relay on the LPF board is not being activated on 80 meters and is allowing a low of 2nd and 3rd harmonic energy get through. A 'scope would show that, but for some reason or another, that makes the 80 meter output look like 10 watts of power on a wattmeter.
Once you get the Low Pass Filter working correctly on all bands, try the KXAT1 again and if the power falls off - I don't think that is a related problem. 73, Don W3FPR On 6/4/2012 6:43 PM, ke9uw wrote: > I just finished the KX1 kit and without the tuner, power output into a 50 ohm > load is about 10W on 80M, and 4W on 40M, 30M, and 20M using a Bird meter, > 50W slug. > However the ATU which seems to work well in all testing, all the relays > click, etc., in TUNE the power starts out at a reading of about 3 watts (40, > 30, 20...a watt higher on 80) and falls off in about 2 to 3 seconds to about > .5 watts. The Bird meter shows exactly the same power fall off. > Also the SWR reading in all cases reads 1.0 using the dummy load. So it > seems like something is heating up (don't feel any heat anywhere) and the > power falls off...but it still always reads an SWR of 1.0 when I go out of > TUNE. > When I remove the ATU and install the jumper the power is steady for all > bands (just higher on 80M). > ______________________________________________________________ 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
