[ILQSO] Powering a laptop

[k8bb at comcast.net]

I would recommend finding a laptop that will run OK on 12v directly (such as 
what Mel describes) and forget about charging while in use.

For mobile QP use, I use an old Compaq 486 (DOS - NA) that has a coaxial 
12VDC jack right on the back. I then zip-tie the connector to the little 
door over the connector cover to prevent it from getting pulled out, thus 
not needing any internal battery for anything. (Which is good, since the 
computer is probably 10+ years old and the internal battery was toast long 
ago.) This computer makes *no* noise and has proved reliable through several 
Michigan and Ohio QSO Parties, including a couple of first place finishes.

I also have similar experiences with some IBM 600E ThinkPads that I 
"inherited" several a few years ago. These computers run on 15-16VDC, but 
seem to be perfectly happy with the roughly 14v the truck produces when the 
engine is running, and produce no noise. Again, the connector is just a 
regular coaxial DC plug, so I zip-tie it to the connector cover door to 
prevent it from getting pulled out and have never had a problem. (I have not 
used this computer for logging, just for GPS navigation.)

Also, I have not used separate power sources. I have powered these laptops 
from separate (fused) cable runs directly to the Jeep battery, just like the 
radio gear.

73!
Don Chisholm

----- Original Message ----- 
From: "Mel Crichton" <kj9c at iquest.net>
To: <ilqso at mailman.qth.net>
Sent: Saturday, December 15, 2007 9:51 AM
Subject: Re: [ILQSO] Powering a laptop


I just went thru this.... I bought an old Compaq Armada cheap but it needed 
16 volts minimum,  I tried a Tripp lite inverter and a cheap DC-DC 
adapter... both caused RFI in the IC-706 mobile.... The Tripp Lite was fine 
until I started the ignition....

I have been told that the expensive (100 bucks) Lind Electronics DC-DC 
adapter has no RFI..... but I choose to go with a laptop that will run on 12 
volts... unfortunately, I did not find one using Win 98 before ILQP 2007, so 
I ran my 1999 Sony Vaio with Win XP on 12 volts and tried MM Logger while 
mobile... not a pretty experience, but the laptop was fine on its own 12 
volt circuit (NOT with the rig!!!)... it could draw about 6 amps at times..

So I  just found a Panasonic Toughbook running Win 98 for 70 bucks... they 
use the 11 volt Panasonic Video Cam battery, and will run on 12 volts DC 
directly from the car supply without battery.... however, batteries don't 
charge much from the 12 volt supply, so my intent is to leave the battery 
OUT except when the ignition is off.... (i.e. push battery in, switch off 
ignition so the laptop does not crash, then pull battery out after igntion 
starts again).... The deep cycle marine battery is another good idea for QSO 
parties and Field Day...

There are MANY laptops (circa 1995-2000) that can run on 12 volts (or even 
11 volts) but need 17v  or more to charge their batteries.... if you have a 
laptop, plug it into the cig lighter outlet, start it up, then pull the 
battery and see if it continues to run. Before you buy, look up the model 
number (Google works) and download the manual to get the battery spec.

Mel KJ9C
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