Sent again....
On 11/02/15 08:24, Dominic Baines wrote:
Lynn,
When travelling I often use a power brick with my KX3. When mains is
available it is a convenient way to power one. There are quite a few
to choose from and I did test the voltage output. The near 12V one's
often vary in output voltage from about 11.8V right up to 14V, mine
will deliver 14.4V @3 amps no problem. I think it was from some bit of
portable test kit, rally purchase, but some of the Dell, Acer and HP
mini laptops used voltages about this level I believe. The other
alternatives that are relatively easy to obtain are 12V DC lighting
supplies or CCTV camera supplies. Needless to say they are switch mode
so can be regarded as the devil spawn by some... but a simple common
mode choke on the mains in and the DC out usually gets rid of most
issues (not seen any myself). I added a big 6amp silicon diode (and a
fuse) in line so it dropped the output voltage to 13.8V nicely). KX3
reports 13.7V. Nice thing is it 'looks' like a laptop power supply so
airport security et al are less bothered than something homebrew in an
ABS/ dicast/Hammond box. Usefully the one I have also has a 5V USB
output for recharging a mobile phone, ipod etc. It also doubles up as
the power supply for my acer one laptop.
They tend to be plastic glued/welded shut so you cannot do much about
what is inside but if you are brave you could rehouse and try and work
out lifting the output voltage, or trimming it back if too high. A
lack of any circuit diagram or knowledge about these things and lethal
main voltages being present precludes me from recommending that course
of action.
I do not have the battery recharger in either of mine and tend to run
without internal batteries anyway but you will need >13.8V to get that
to work, but you could also use a separate 12V to 8AA recharger too I
believe.
72
Dom
M1KTA
#1082 and #2334
On 10/02/15 22:57, Lynn W. Taylor, WB6UUT wrote:
I don't disagree with any of the theory.
I was hoping for some responses based on actual experience.
-------- Forwarded Message --------
Subject: Re: [Elecraft] KX3 power supply "brick"
Date: Tue, 10 Feb 2015 17:10:55 -0500
From: Nr4c <[email protected]>
To: Lynn W. Taylor, WB6UUT <[email protected]>
You'll need at least 13.8 volts to charge the batteries.
Sent from my iPhone
...nr4c. bill
On Feb 10, 2015, at 3:57 PM, Lynn W. Taylor, WB6UUT
<[email protected]> wrote:
I just looked at four bricks floating around my office, and two of
them are 12v. The other two are 18v and 19v.
The smallest one I have is 2a, which would probably charge the
internal KX3 batteries. The bigger one might be okay for transmitting.
That's why I specified "12v brick" in my post. There are many
different bricks out there.
73 -- Lynn
On 2/10/2015 12:34 PM, Walter Underwood wrote:
Most laptop bricks are 16V or higher, too much voltage for the KX3.
wunder
K6WRU
CM87wj
http://observer.wunderwood.org/
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
