[Elecraft] K2 Voltage Display

Fri Feb 14 19:44:00 2003

Hi Gordon,

The voltage that's displayed is the internal 12V line after a series diode
(D10 on the RF board). The diode is for protection against reverse voltage.
If you measure across a power supply or battery outside the K2, it will be
0.4 to 0.5V higher.   This difference in voltage is fairly constant, so if
your battery goes down by two volts, the display will track it accurately.
The display is probably within about 1-2% and it has 0.1V resolution.

The display is an accurate reading of the voltage seen by  the circuits in
the K2.  As long as it stays at or above 10V, you're okay.  Below 10V, the
audio amp may be affected. Below 9V, the output of the 8V regulator may
start to drop.

73/ Bob - AG5Q

----- Original Message -----
From: "Gordon Gibson" <[email protected]>
To: <[email protected]>

> How accurate should the voltage display be ?
>
> The display on my K2 #2746 appears to read .7v low,  since my K2 was
> completed last August I have only operated it from the shack, and never
gave
> the voltage display much thought, however I intend to go /p this Spring
and
> Summer so have been getting ready for that, and charged up my Hitachi 12v
> 6.5A battery, it was when I connected to the battery I realised the
Battery
> Volts were different to the K2 Display, so I checked the voltage of my
Drae
> Power Supply and it too is reading .7v higher than the K2 Display!

> So is the Display only relative ? or do I need to change the values of the
> Potential Divider on the control board, i.e. R9, R10 ? in order to get the
> display to read my true battery voltage ?
>
> 73 de Gordon G3ZFZ
>
> [email protected]
>
>
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