[Elecraft] Config: ADC REF (revisited

[Paul Christensen]

> my K3 now shows the supply voltage as being 13.6 volts, but when i
> measure the supply at the output of my PS it shows 13.76...  the
> cable is only about 12 inches, so that seems like a pretty steep drop.

I wouldn't be concerned about a 0.16VDC discrepancy since you're looking at 
the supply voltage as measured on two separate devices at two separate 
locations.

With your DMM, measure the supply voltage on both ends of the 12" power 
supply cable with the K3 powered-up. If you're using the supplied cable from 
Elecraft, the two readings should be very close on a 12" cable with ~ 1 A of 
DC current.  Subtract the two numbers.  The subtracted amount represents the 
voltage drop on the power cable.  Any remaining amount is due to: (1) a 
slight accuracy discrepancy between the DMM and alignment of the K3's 
internal voltmeter; and (2) any slight additional drop associated with the 
APP connectors and internal K3 wiring.

Also, you may want to take the time to ensure that the APP pins on your 
power connector are aligned properly.  Voltage drop on an APP connector is 
highly correlated to pin alignment since there's no concentric pin/socket 
friction as there is on Molex and AMP Mate 'n Lok style connectors.

Paul, W9AC