[Elecraft] KX1 internal battery

[Jean-François Ménard]

OK now I see your point.
 
But I use my regular DC power supply as an external source at home..... So
the power is not supposed to be less than my batteries... I hope so ;-)
 
But if I go on a field trip using external 13.8V batteries to have more
power instead of a steady DC power source , OK now I will be aware of that
behavior....
 
Thanks
 

-----Message d'origine-----
De : K6TFZ at aol.com [mailto:K6TFZ at aol.com] 
Envoyé : 24 janvier 2005 10:06
À : jfmenard at mac.com
Objet : Re: [Elecraft] KX1 internal battery



In a message dated 1/23/2005 2:02:23 PM Pacific Standard Time,
jfmenard at mac.com writes:

Many people answer yes, and you say no..... who is right ???

I had to find the information that upon which I based my answer.
 
Here is a copy from the archives from 
 <http://www.ac6rm.net/mailarchive/html/elecraft-list/2004-03/msg01106.html>
http://www.ac6rm.net/mailarchive/html/elecraft-list/2004-03/msg01106.html 
immediately below:

 
Here is another  KX1 battery switching modification.
The current design "AND's" the internal battery and external battery sources
together using 2 diodes.
If your external battery voltage goes below the internal battery 
voltage, the internal batteries will start draining.
i left my KX1 on for a few days and after i ran down the external battery
and
the internal batteries took over and became discharged.
These were the expensive Lithium "AA" Primary batteries (L91's).
i wanted to save the use of these Li batteries for special uses
like Pedestrian Mobiling: See the w0rw/pm KX1 report on the Adventure Radio 
Society web site at:
http://www.arsqrp.com/ars/pages/back_issues/2004_text/0204_text/W0RW.html

Here is the DC J1 switching Modification:
The DC Power connector has an unused (normally closed) switch.
This modification will use that switch so that when an external power source

is connected the internal batteries will be disconnected, and conversely
when
the DC power plug is removed the internal batteries will be reconnected.
Open the unit on an ESD grounded work station.
Separate the battery compartment by pulling the battery connector (J1) out.
Cut the 2 traces that ground P1-2 "-" (getting scary now)...Top Side..
Now add an insulated jumper wire from P1-2  "-" to the side contact of J1
(J1 is the power connector), The unused switch contact is soldered to an 
isolated pad just the left of the marking 'Z2'...
That's it....
Now you can protect those internal batteries.
One other thing that you can do is to set the LED Display Control to "INF"
then the LED display will act as a pilot light.
72  de w0rw
 
Now you can question others further and take your choice.
 
Geoff, K6TFZ