[Elecraft] P3 abnormal shut off problem

[Don Wilhelm]

Tom,

That sounds strange.  I would first suggest checking all the Power 
Supply to K3, and either K3 AUX DC to P3 or the Power Supply to P3 power 
cables for loose connections.

A drop from 14.5 to 14.7 volts down to 12.8 volts indicates a high 
resistance power cable or a bad power supply.

Measure the voltage at the power supply terminals to determine whether 
it is the power supply or the cables - if the voltage stays up at the 
power supply terminals, but the voltage sags at the K3 end, the cable is 
to blame.

OTOH, if the voltage at the power supply terminals sags significantly, 
then the power supply regulation is at fault.

Make certain all power cable connections are tight.  Power cables 
wrapped around the terminals are suspect (use ring terminals), as are 
the power supply terminals designed to "insert the wire and flip the 
lever" which may not guarantee a good tight connection.

73,
Don W3FPR

On 10/25/2019 5:44 PM, Tom Azlin W7SUA wrote:
> Hi. My P3 has started turning off a few seconds to a minute after I turn 
> on my K3/P3 or when I then try to turn my P3 back on. I was watching and 
> saw no error message like low voltage. Watching also the voltmeter on my 
> K3 and stayed at 14.5 to 14.7 volts. dropped power supply to 14 volts 
> and it still shut down. Did a tune and voltage was 12.8 then back to 14 
> then afterwards it shut off.
> 
> Is my power supply not holding up properly?
> 
> Will dig out a spare power supply next.
>