[Elecraft] K3 voltage drop

[Bill Harris]

I am experiencing the same problem with my K3. Using the factory supplied power lead. I measure a 1 volt drop between the power supply terminals and the K3 voltage reading at 100watts input (15.68 amps). I suspect most of the drop is from the power lead and if so, seems a little excessive. I'll measure directly across the PL to confirm this.

Later
Bill Harris w7kxb

> Date: Wed, 5 Mar 2008 13:05:00 -0500
> From: w3fpr at embarqmail.com
> To: marshalldenny at gmail.com
> Subject: Re: [Elecraft] voltage
> CC: elecraft at mailman.qth.net
> 
> Marshall,
> 
> There is no adjustment - The voltage measuring circuits are usually 
> quite accurate (fixed with 1% resistors).
> 
> 1 volt is a lot of difference.  Normally there will be a 0.3 volt 
> difference between the actual power supply voltage and the voltage 
> internal to the K2 because of the voltage drop across the reverse 
> polarity protection diode D10 and there may be a bit of voltage drop 
> across F1 (the resettable fuse).
> If you really have a 1 volt drop, you should look for a bad solder 
> connection in the DC supply line.
> 
> Also, where are you measuring the  voltage?  If you are measuring it 
> directly at the power supply, examine the connecting cable carefully and 
> be certain its connection to the power supply is tight - loose 
> connections will cause a significant voltage drop which varies with the 
> current drawn.
> 
> 73,
> Don W3FPR