[HCARC] Allowable Voltage Drop for 12V Mobile Install

[Kerry Sandstrom]

Harry,

Depends on the rig. I think the nominal voltage in a car system is around 
13.6 V. I've had older 2 m FM solid state synthesized rigs, ICOM IC-255, 
that really wouldn't operate on 12 V. The synthesizer seemed unhappy and 
got very noisy. Does the same thing on a regulated supply in the shack when 
I try to run it on a regulated 12 V. It really wants something above 13 V. 
I believe most of the HF rigs are rated for 13.5 - 14.4 V. If you have an 
adjustable regulated DC supply in the shack, you can try dropping the 
voltage down and see where the rig starts being unhappy. With lower DC 
voltages, the power output will be less also. In general, I expect it will 
be the synthesizer that acts up first as you drop the voltage. I've even 
seen rigs that got unhappy when the alternator wasn't charging and the 
battery voltage dropped a bit. That's been my experience. Let me know how 
you make out.

Kerry