[Elecraft] KBT2 charging question

[N2EY at aol.com]

In a message dated 11/2/06 11:50:28 AM Eastern Standard Time, 
ncsailors at yahoo.com writes:


> Sounds like an Elecraft design glitch!

It's not. It's actually a very good design.

  Why would
> 
> one want to adjust their DC 13.8VDC Astron, to make
> up for it?  

Because it's what is needed.

Circuit needs a mod.
> 
> 
No!

Elecraft rigs are, above all else, QRP CW rigs. They are meant to be as 
portable as possible, which is why the small size and provision for internal 
battery.

The battery needs a certain voltage for charging. That's determined by the 
type of battery used, and the power supply/charger must be adjusted to deal with 
it, because the battery is not adjustable.

The blocking diode is a special low-drop part, to waste the minimum of power. 
It serves two purposes: 

1) to protect the rig from reverse-polarity applied to the power input jack, 

2) To prevent discharging the internal battery into an external load. 

In portable operation, and even at home, the diode prevents a lot of possible 
problems. The design is very well thought out and needs no changes.

There's nothing magic about 13.8 volts, btw, 

73 de Jim, N2EY