[Elecraft] KBT2 charging

[Tim Ostley]

Dear Ron,

One thing to remember is that the internal voltmeter function of the K2 
is specified as +/- 5%.

When I read this spec as I was building my K2 I thought great that seems 
to be reasonably accurate.

When I added the KBT2 option I ended up measuring the various voltages 
with an accurate (1% or better) meter. I then did the calculation, 5% of 
13.8v is 0.64v, in otherwords the K2 could indicate anything between 
13.16v and 14.44v!! This is without taking into account the voltage drop 
of the diode.

My measuremets showed me that the voltage at the power jack was some 
0.7v higher than the K2 displayed. Having adjusted the power supply I 
was using to give 13.8v on the K2 display, I quickly adjusted it back - 
I was actually feeding the K2 with 14.5v!


72's

Tim M0CZP