"Gary Smith" wrote in message
...
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.
I just wanted to know if it was capable of handling that (which i presumed
it would be ) as the lap takes about 60w maybe and the transmitter 100w at
times.

Anyway, if someone can please explain why a 300w inverter won't run 160w
of gear i will be very happy.

It's not so much that it won't RUN the gear, the gear simply won't be very
usable.

The output from these type of inverters is a very strange waveform, a sort
of three step square wave with a ring at each step. And all that noise shows
up in your receiver AND in your transmitter. The filtering in the rig is
just not designed to deal with the complex, harmonic rich waveform at the
output of the inverter. I've even tried running the output through an
isolation transformer, but it did no good at all. You may be able to make it
look somewhat like a sine wave if you could find a proper transformer to
make a tuned tank at 50 Hz, but no telling what voltage you would be getting
out of it. The voltage on my 300 watt 120V/60Hz inverter is 380V peak to
peak (190V peak) with so much garbage in it that my frequency counter can't
even SEE the 60 Hz component.