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KX1 Power / Meter

Posted by Jim - W6VAR on Jan 03, 2012; 8:54pm
URL: http://elecraft.85.s1.nabble.com/KX1-Power-Meter-tp7148148.html

I was just reviewing the power output on my KX1 on various bands and came up with the following results:

Band Int Batt Ext  Bat Ext w/Tuner Ext Bat on 40M Doublet 13.8 Volts
20 1.0 3.0 3.0 4.3 3.9
30 1.4 3.9 3.7 1.7 4.6
40 1.5 3.6 3.6 4.7 4.3
80 1.5 3.9 3.7 4.4 4.4


All were into a 50 ohm dummy load except for the 40M ladder line fed doublet that had a 1:1 balun near the radio. Power readings on a W1 watt meter.

Scenarios:
1. Internal Batteries Energizer Lithium 50 ohm dummy load, tuner bypassed
2. External SLA battery (about 12.5v) 50 ohm dummy load, tuner bypassed
3. Same but with tuner in line
4. External SLA battery with 40M doublet and tuned for a match.
5. 13.8V regulated power supply with 50 ohm dummy load

Initial readings seemed to make sense, but I had the following observations / concerns:

1. at 13.8 volts input, the power went over 4 watts on all but 20M, which was close at 3.9. Is this running too hot and should I reverse the power output mod or only operate at lower voltages?

2. The power output when the antenna was hooked up went up considerably on most bands. Why would this happen and should I be concerned?

3. There was a significant difference between the W1 and the KX1 wattmeters when the antenna was hooked up (several watts), whereas they were within a few tenths of a watt in the dummy load. Again, anything to worry about? What could cause this?

Thanks,

Jim - W6VAR

I have performed the modification