[Elecraft] KBT2 charging question

[Tom McCulloch]

I want to make sure I'm following this.  I

 need to see 13.8 volts immediately after the protective diode.  Is that 
correct?

Thanks
Tom
WB2QDG
K2 1103



----- Original Message ----- 
From: <N2EY at aol.com>
To: <ncsailors at yahoo.com>; <elecraft at mailman.qth.net>
Sent: Thursday, November 02, 2006 10:22 PM
Subject: Re: [Elecraft] KBT2 charging question


> 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
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