[Elecraft] K3 Voltage on TX

[Jim Brown]

On Mon,10/26/2015 8:48 AM, Rich wrote:
> My K3 shows 13.7VDC on RX. When I TX that reading drops to 10.9VDC. Is 
> that a normal drop? 

It's not good. Two possible reasons -- poor regulation of the power 
supply and IR drop in the power cable.

How long is the power cable between the K3 and power supply?  What wire 
gauge?  Do the arithmetic for Ohm's law for the IR drop in that length 
of that wire gauge. and remember to use the length of the cable x2 (for 
two conductors). Resistance per ft for various wire gauges is in the 
ARRL Handbook.

Put a voltmeter across the output terminals of the power supply and 
check the voltage. It's also possible that the power supply has poor 
regulation.

73, Jim K9YC