[Elecraft] normal K3 voltage drop on TX

[Jim Brown]

On Fri,8/21/2015 11:52 AM, Richard S. Leary wrote:
> RX	13.9V @ 1.15A
> TX (100W CW)	12.6V @ 19.62A
> Readings from K3 VFO "B" display of "V" and "A"

The difference includes the IR drop in the red/black power cable between 
the power supply and the K3. Some quick arithmetic. #10 AWG is 1 
milliOhm per foot. A 6 ft cable would be 12 m Ohms (two conductors), so 
.216V drop at 18A. With #12, it's .35 volts, .54 volts. Subtract the 
numbers for your cable (factoring in the length) from the difference, 
and that's the sag in power supply (and, of course, resistance internal 
to the K3).

A better way to measure the sag in the PSU is with a digital voltmeter 
connected across it's output terminals.

73, Jim K9YC