[Elecraft] K3 power supply

[Ron D'Eau Claire]

How do you have the battery installed Jim (considering what it's filled with
and that even "sealed" batteries can out-gas flammable hydrogen at times)?

One ships the backup batteries were always in a steel locker on the deck
*outside* the "house" (enclosed superstructure). I've considered doing
something like that here but it requires keeping the batteries reasonably
warm to avoid compromising their capacity. 

Ron AC7AC

-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Jim Brown
Sent: Thursday, December 25, 2008 11:47 PM
To: Elecraft List
Subject: Re: [Elecraft] K3 power supply

I use a big battery that I bought at Costco for $75, float-charged 
by a 10A switching power supply that I bought at a hamfest for $10. 
I had to add RFI filtering to it. This keeps up with my K3 driving 
my Titan amp in very heavy contesting (30-35w from the K3), and I 
can easily get full output from the K3 when I run barefoot. 

This rig has two HUGE advantages. First, it's VERY efficient, only 
drawing about 400mA from the power line when it's floating the 
battery at about 4A and running the radio and accessories. My 
Astrons draw about 5 times that just sitting there with no load. 
With California rates for electrical power, that's a very nice 
difference. Second, it's a pretty beefy UPS! 

73,

Jim K9YC