[Elecraft] K3 Voltage on TX

[Phil Wheeler]

If the wire gauge is OK and the supply regulation 
is not at fault, give some attention to the 
connectors at each end of the cable, too. A drop 
of 2.8 Volts points to some sort of issue.

73, Phil W7OX

On 10/26/15 9:02 AM, Jim Brown wrote:
> 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