[Elecraft] K1 with internal battery

[Tom Althoff]

WOW!  Great job Steph!

I happen to have a 3-pin socket handy here.   I think add the diode to the
RF board and follow your example on the stock K2 cover too.

Plus the 9-volt snap connector is fast.  Also allows 1 or 2 quick contacts
with a  9 volt transistor radio battery in a real emergency.  Neat idea!

Tom K2TA

----- Original Message ----- 
From: "Stephanie Maks" <va3uxb at maksystems.com>
To: <elecraft at mailman.qth.net>
Sent: Wednesday, December 28, 2005 3:53 PM
Subject: Re: [Elecraft] K1 with internal battery


> >
> > The KBT1 should have been made easily removable so that the
> > compromises associated with having it installed need only be
> > suffered when absolutely needed.  The KBT1 *should* attach via a
> > cable with a polarized two-pin female connector to a male connector
> >  *anchored* on the RF board.  This would allow easy removal at any
> > time.  The current design has the connections made by soldered
> > connections, and even if you jury-rig in a connector in the power
> > leads, one side of the connector will then be floating ar
> > ound creating potential shorts when the KBT1 is removed.
> >
> > 73,
> > Mike / KK5F
>
> I got the KBT1 kit but haven't really used it yet.   I have made some
> modifications though that will make using it much easier, including
> adding my own jack on the RF board so that I can add / remove the
> entire battery kit without soldering.
>
> Where the two solder points are to wire in the auxiliary 12 volts,
> the + point is directly under the switch, but the - point was next to
> the switch. I got a 3-pin female socket, similar to the one you get
> with the ATU - it's a 0.1" spacing 3 conductor socket.  Anyhow I
> drilled a hole in the RF board, and mounted the 3-pin socket there.
> The two outside pins are both ground, and the centre one is for +12
> volts.  (not quite as good as a polarized plug, but I just used the
> parts I had laying around). I used the special diode they supplied
> with the KBT1 to go from the centre pin of my 3-pin connector, to the
> power switch - rather than having the diode being part of the KBT1
> assembly itself, this means the diode is right on the RF board, on
> the bottom.  Finally, I used some hot-melt glue on the top side to
> provide additional strength to the 3-pin socket.
>
> For the wiring from the KBT1 bracket I used the supplied red and
> black wiring, and just terminated it on a 3-pin header.
>
> The last thing I changed was rather than using discrete AA sized
> rechargables, I had a battery pack assembled.  This allowed me to use
> the larger diameter AA type cells.  Without the plastic battery
> holder there is more room for batteries.  So I have a 9.6v 2000 mAh
> battery pack made up.  On its terminals I added a '9-volt' style snap
> connector, and to the KBT1 switch I put another '9-volt' style snap
> connector.  This lets me easily pull the battery pack out and drop it
> into my Maha quick charger, without removing the KBT1 bracket etc.
> I still have the 8-AA plastic holder of course, and with another 9-
> volt style snap connector on that, I can just as easily drop that in
> and load it with off the shelf AAs if needed.
>
> In the meantime, I also used two small strips of brass to add a
> little 'lip' to the stock K1 top cover, because I like the ease of
> opening it with just the two knurled thumbscrews at the back.
>
> So now the whole process of switching from the 'normal' K1 to the
> battery powered unit takes me under a minute - just unscrew the
> thumbscrews, remove the stock lid and speaker, drop in the KBT1
> bracket, plug in the speaker, plug in the power cable, and put on the
> KBT1 lid and screw it down.  No tools required at all.
>
> 73 de
> Stephanie
> va3uxb
>
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