On Sep 26, 11:07*pm, Fred McKenzie wrote:
In article ,
*"Gary Smith" wrote:

Hi all, i purchased a 12vdc to 240vac inverter for using my laptop. it's a
300 watt model fromm Jaycar.
I asked the person running the shop if i could run my 100w IC725 from it. NO
WAY was the reply.

I was thinking of running the DSE D-3800 power supply from it when out on
contests and running the laptop and ssb hf rig from it.

Gary-

This is one of those things you can try and see if it will work!

Instead of estimating the power your equipment needs, you need to find a
way measure it. *I measured power consumed of an HF rig putting out 100
Watts CW, and found the actual AC consumption was about 350 Watts.

JB-

As far as needing 13.8 Volts instead of 12.3, there is a product on the
market designed just for that problem. *One version was published in QST
several years ago, and may be currently marketed by the original author. *
Another variation is the MFJ-4416.

Fred
K4DII

Gee yes: Just because the final amp. of a transmitter is rated 100
watts DC input and may put out 70% of that as RF doesn't mean the
whole unit 'uses' 100 watts!
If it is a tube unit with tubes to heat and standby and a receiever
portion it could easily be consuming several times100 watts. Measure
it!