[Elecraft] KX3+KXPA100 operation improved when running from a 12-V battery

[Jim Brown]

On 1/14/2014 7:36 PM, Wayne Burdick wrote:
> At lower voltages, especially in voice modes, you should consider dialing back power output to preserve the amplifier's "headroom." For example, if the supply is dipping below 11 V,

I would work on raising the battery voltage, and on reducing the IR drop 
in the wire. Wire is easy -- bigger, shorter.  As to battery voltage -- 
what kind of shape is it in?  How do you charge it?  For many years, 
I've run everything on my operating desk, including the K3 and P3, from 
the biggest deep discharge battery that Costco sells, float-charging it 
with a little 10A supply that regulates to 13.8V. With that kind of 
setup, I rarely saw anything less than about 12.5VDC on the K3 
voltmeter, and I never ran out of juice, even with heavy contesting. And 
batteries don't last forever. I've gotten 3-4 years from the setup I've 
described.

BTW -- distortion (splatter, clicks) also increases as DC supply voltage 
falls, so you'll have a cleaner signal at full power with higher battery 
voltage.

73, Jim K9YC