At 11:33 PM 5/18/2010, Kyle Mcallister wrote:
With some spare time over the weekend, and little to do (a rarity),
I decided to make a crystal-less crystal radio. Inspired by Nyle
Steiner's work (google him, he is a god among amateur scientists), I
conducted a couple hour's worth of experimenting with using flames
as a detection method for RF. No kidding, it works!
http://www.youtube.com/watch?v=fMQEiRWoiJw
Is it practical? No. Was it fun? Oh yes.
Better page: http://www.sparkbangbuzz.com/flame-amp/flameamp.htm
Unanswered questions: why are American kids not doing this sort of thing?
I'm sure some are. I made a crystal radio that was powered from loose
RF floating around, I must have been about 12 or so. I was more
interested in stuff that went bang. I don't recall how I happened
upon a flash explosive that was aluminum powder, sulfur, and
potassium permanganate as the oxidizer. Cool stuff.
Anyway, I'm an American kid, still, I'm just older....
Why are they relying on their iPhones to do everything? "There's an
app for that... guh..."
Now, I'd probably be writing those apps if I didn't have other even
more interesting stuff to do. I was totally intrigued when I fell
into a job repairing a stored program controller for a
phototypesetting machine. This thing had a spinning drum with a film
with the characters on it around the rim, and a flash tube inside.
The controller accepted data from a punched paper tape and would then
flash the tube at just the right time to expose photographic paper to
the light in the shape of the character. Then it would step the
position of a mirror, as I recall, according to the standard width of
that character.
Anyway, the idea that this SPC was spending most of its time waiting
for this drum spinning quite rapidly to come around to position was
intriguing. It could "think" much faster than the drum could turn.
Magnetic core memory. Got me interested in computers, so I built an
Altair 8800 when it was announced in Popular Electronics in the 1970s.
The SPC used flat pack versions of standard logic. Nothing
complicated. I assume that flat packs were used because at the time
it was being designed, probably 1960s or around 1970, the military
versions of ICs were more available.... but I'm not sure. I think the
photosetter cost about $40,000. The printer I was working for still
had linotypes, cool machines all on their own.
--Kyle, longing for the days of Heathkit and the OLD Radio Shack...
Well, I can understand, but I don't really miss that. Heathkits were
cheap, main point for me at the time, I built quite a few, but
assembly costs are now so low that a Heathkit to do what I can easily
buy fully assembled and tested, etc., would be much more expensive. I
just bought a Rigol 50 Mhz dual channel digital storage oscilloscope
for under $400, color display, compact, a beautiful piece of
equipment that I'd have given my eye teeth for twenty years ago when
I was working in electronics actively, instead of just as a printed
circuit designer. I'll be using it to look for shock waves from a
palladium deuteride cathode, one piezoelectric sensor will be on the
heavy water cell, one on the light water cell.
Tell me, is that fun or what?
I just tested LR-115 solid state nuclear track detector material with
an AM-241 source ripped from a smoke detector. Too bad the smoke
detector had to die, but it was for a good cause and the detector
only cost $6.49. I used a Celestron LCD digital microscope to examine
the etched detector, and I describe what I found in a post to
http://tech.groups.yahoo.com/group/coldfusionproject/?yguid=40611328
LR-115 appears to be a much more easily used SSNTD material than
CR-39. The alpha tracks from the source, striking the detector
surface, which is a thin, 6 micron, layer of cellulose nitrate on a
100 micron polyester film, after etching, and if the angle of
incidence isn't normal to the surface, show a cone of decreasing
radius of disruption, very easy to see. I will be running more tests
to determine optimal etching time; this test used the longest time
recommended, 40 minutes, in 2.5 N NaOH at 60 degrees C. After
thoroughly imaging the test strip, I intend to etch it some more to
see what happens. Looking at the film, it seems that there are many
more tracks that didn't cause a pit all the way through the sensitive
layer (which is red).
I'm selling the material, $27.80 per 9x12 cm. sheet. Be the first on
your block....
