[Elecraft] Current use K3/10 vs. K3/100

[Bill Frantz]

Remembering the thread about how much current a K3/100 used when 
powered off, I decided to run a test as I installed the KPA3 in 
K3 #6299. The table below lists power use before (K3/10) and 
after (K3/100) 100w amp was installed. A monospaced font will 
help legibility.

Test conditions: Direct connection to a 12v battery. RF and AF 
gain at zero. CW mode. No RS-232 connection. P3 power unplugged. 
IF out disconnected. MFJ dummy load. Tuned to 14.0475. Fluke 87 
meter for current. Internal K3 meter for voltage. Straight key 
held down until current reading stabilized (c10 seconds.)

K3/10            K3/100           Measurement
0.1microA N/A V  4.1mA N/A V      Power off idle current
873mA 12.1V      969mA 12.1V      Receive
2.57A 10.8V      2.87A 11.0V      Transmit 5W
3.19A 10.4V      3.53A 10.6V      Transmit 10W

The K3/100 uses 11% more power on receive, 12% more power on QRP 
transmit, and 11% more power on ten watt transmit. It may be 
worth removing the 100w amp for QRP battery field day like operations.

Note that the PA temperature calibration changed the value by 3 
degrees C. (This time I put a brewing thermometer next to the 
radio to act as the "standard" temperature. The last time I 
think I used the wall thermometer.) The MacIntosh K3 Utility did 
the Wattmeter calibration. As far as I know, these were the only 
changes to the radio's settings.

Cheers - Bill, AE6JV

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