[ILQSO] FW: Laptop mobile power question

[Jimk8mr at aol.com]

In a message dated 1/25/05 1:35:38 P.M. Eastern Standard Time,  
wn9nbt at purdue.edu writes:


When  operating mobile or portable, what is the best way to power a laptop
used  for logging?


 
DC to AC inverters are almost always very noisy.
 
I have had good success using a "Car Adapter" or whatever they call the  
DC-DC power supplies.  I use an (by now ancient) IBM ThinkPad 760C with a  car 
adapter I got on eBay for about $30.  There is essentially zero noise  from the 
computer. But still lots of noise from the car  :>(
 
YMMV, but I have always used a separate 12 volt battery, basically to keep  
things from all having to come off the car's electrical system.  A few  years 
back I suggested to K8CC that he solve his laptop noise problem by the car  
adapter route.  He still had lots of noise until he got a separate battery  for 
the laptop, which then cleared up his noise.
 
A 20 AH battery will run a 12 hour contest, but with not much to  spare.
 
My next road trip will be the Michigan QSO Party on April 16.   See you then!
 
 
GL,
 
Jim   K8MR