Human-powered portable power generation
 

"Bill Horne, W1AC" writes:

Jon Kåre Hellan wrote:

[snip]


Some months ago a portable, steam powered WWII agents' generator was
on ebay.

Jon,

I never would have thought of that.

Do you have URL or item number, or any other information? TIA.

I didn't find the ebay auction. But I found this from QRP-L in 1996
(http://www.kkn.net/archives/html/QRP...sg01007.html):

During WW2 there were a number of unique radios made principally by the
Britts for the underground in Europe. After the war a number of these found
their way into surplus stores in Australia. I had one of these (and how I
wish I still had it but it was stolen years ago). This radio had as its
power source a steam driven generator. This comprised a boiler about 2-3
gallons as I recall and a very neat little engine driving a 6 volt generator
which was used to charge a lead acid battery. The boiler could be heated in
any way including an open fire or a primus stove or whatever. The radio had
an 807 in the output (cw only) and put out about 5 watts. I built a small
modulator for it and had a lot of fun on AM in the portable mode.
Regards
Dave KI6QE/7 VK2IMJ

Seriously, a 20-50W generator would be very useful for emergency
communications if it could be made light enough. An improvised
repeater placed on a convenient hill or mountain can do a lot of good,
but you'd have to carry it on foot. At a good location, output power
doesn't have to be high. Solar needs to be backed by heavy
batteries. How light could such a generator be made?

And viewed from a different angle: What's the minimum power you'd need
for a cross-band repeater with 5 W output? Would other technologies
than FM repeaters be more useful?

73 de LA4RT Jon, Trondheim, Norway