Good luck on that SB-301. It's a real beauty.
On the (Water) Level
The July 2016 Water Pump Protection System article
by Joe Bidwell states on page 36: "I monitor the water
level with a pressurized nylon tube that I taped to the
pump before lowering it into the well."
I would like to know more about the water level
monitor; how does it work, details about implementation,
(With a 150 foot deep well
that has a low water level.)
I hope a picture (below) is worth a thousand words in
this instance, since this system is a little hard to
communicate in words. I don’t know much physics, but do
remember that a column of water develops pressure based
on height. I used that principle in my system:
1 foot of water = 0.433 PSI
1 PSI = 2. 31 feet of water
My own well is 500’ deep and the water is usually
about 270’ below ground, so I typically get about a 100#
reading showing that I have about 230’ of water in the
well. Hope this is helpful!
Nailed the Magnetos
In regards to the answer published in the July 2016
issue for question #6145, I feel it is slightly misleading. A
“keeper” put across the poles of a “horseshoe” type
permanent magnet will greatly reduce the slow weakening
of the magnet by shunting much of its field from external
I recently cleaned up two similar old telephone
magnetos, whose magnets were pretty old and weak
(hundred years? I don’t know). I first tried quite a few turns
of #22 wire on each pole (in series, wound in opposite
directions on each pole), and turned 10 amps/12 VDC
loose until the coils got a little too hot for me. The magnet
now certainly picked up a longer chain of nails than
before, but I thought a piece of steel like that perhaps
could do better.
I wound different coils on each pole, #12 common
THHN house wire, with as many turns as I could crowd
on each pole (plus a few wraps of thin cardboard under
the winding so it would slide on and off with a little
urging). I connected my auto battery charger to the
coils (in series again), and switched the charger to the
100 amp “start” position. A few five or 10 second
pulses and the coils were almost too hot. THAT DID IT!
The magnet would now pick up the whole box of nails.
I was so proud! A magneto overhaul facility had
quoted $90 each to charge them on a professional
magnet recharging machine.
Lynn W7LTQ since 1948
Need Know-How? Join the Service
In response to the question posed in a recent Nuts
& Volts content newsletter on what advice would you
give if asked how to get started in electronics, I would
say join the Air Force or Navy in an electronic field of
study. They will teach you basic electronics, then send
you on to advanced training in your specialty. After you
finish school — which will take longer than a year —
you can serve the remainder of your time relatively safe
compared to the Marines and Army. The Air Force
does not typically send its most highly trained
technicians into harms’ way. I'm not saying that it can
never happen, it is just unlikely.
Once you are out of the service, you can continue
your education under the GI Bill, which is much better
than the GI Bill I had when I served. If you like being in
the Air Force or Navy, you can make a career out of it.
64 August 2016
READER FEEDBACK Continued from page 57