[Elecraft] KX3 PS Voltage Display Accuracy?

[Walter Underwood]

The KX3 has a Schottky diode as protection against connecting an external power source with reverse polarity. The voltage drop is typically about 0.3 V during receive.

wunder
K6WRU
Walter Underwood
CM87wj
http://observer.wunderwood.org/ (my blog)

> On Jun 11, 2019, at 1:34 PM, George Pasek <pasek001 at umn.edu> wrote:
> 
> I have a external TalentCell 12v Li-Ion 12800mAh Battery Pack that I have been testing on my KX3.  At the same connection point as the battery (KX3 9-15vdc Power Input) I have my Fluke 177 multi-meter and a EB_M05 that I use to plot the battery pack voltage discharge.  I noticed that the Fluke 177 and EB_M05 will both read the same battery pack voltage but the KX3 voltage display shows about 0.2v lower on Receive and about 0.6v lower on Transmit, as if there was a series diode involved with the display voltmeter.  The KX3 10w output is rolled back to 5w when the KX3 voltage display drops below 10.0v.  So at this point on transmit where the KX3 is displaying PS 10.0v, the Fluke and EB_M05 are showing 10.6v.  If the KX3 were displaying the same as the Fluke (10.6v) I would have a additional 0.6v @ 2000ma available to support the “Use higher power at 10 V only when necessary to complete critical communications”.
> 
> George
> 
> WD0AKZ
> 
> 
> 
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