BNB Sound wrote:

I know there's a lot of designs to make a 12v supply from a deisel
truck alternator and a push lawnmower engine. You might need a couple
extra pulleys to get it geared down to where it's comfortable to crank
by hand (or foot), but it ought to be possible. The reasons for using
a semi alternator are that the 12v regulator is built in and it
simplifies things; also these trucks typically idle at about 1/3 the
rate of a gasoline engine, they have to maintain voltage at low speed.
You can idle down that Toro and run your rig all night on a gallon or
two, it would seem like running a receiver, QRP rig, or even 100w for
short bursts ought to be possible on a meat powered rig.

Jon - KC2PNF/A



Jon,

Thanks for the info: these are good ideas.

I'd like to talk some more about solutions like these: the problem I'm
thinking about is the lack of power in the days immediately after a
Katrina-type event, where the only sources will be the ones found on
every street corner.

There are automobile batteries on every street corner, there are cars,
and there are lawnmowers. The question is how they could be combined to
provide power for ham rigs: I'd bet that 12v batteries would be the
first step, since most ham transceivers run off 12v now, and the
batteries could at least be rotated between cars and radio for charging
and use, respectively.

The question would be how to charge the batteries without relying on
cars, since working vehicles are a valuable asset in themselves and fuel
may also be in short supply: I suppose we could devise a "standard"
method to hook batteries to working vehicles so they could be carried
around while being charged, but that's about it.

That leaves the charging problem. If we can make a "standard" set of
plans that allow a team to dismount an auto alternator and connect it to
any source of torque, we'd have a lot more flexibility: broken-down cars
are always in good supply.

Lawnmower engines interest me because there are only three or four major
manufacturers, which means a lot of common parts and so forth. Nobody's
looking to mow their lawn right after a hurricane, so it's not a
resource conflict.

I don't want to get too far afield, so I'll leave it that: the idea is
to prepare response teams to improvise from local materials, but we need
something in between jumper-cables and windmills.

Bill


--
73,

Bill W1AC

(Remove "73" and change top level domain for direct replies)