28 Mar
2001
28 Mar
'01
10:46 a.m.
From: Tony Duell <ard(a)p850ug1.demon.co.uk>
I read somewhere that a piece of coke (the fuel, not
the drug, OK :-))
was used by POWs in the second world war as a detector. Using much the
same cats whisker arangement as with the galena crystal. Might be worth
a
try.
I will work but you want to find a peice that has really been fired and
has a
bit of rainbow color to it. IT's the contaminating oxides and all that
makes it
work though germainium is better.
I would recomend getting the set working with a
germanium diode first.
Then, when you know the coil, tuning capacitor, headphones, aerial,
earth, etc are OK, try the home-made detector.
Good way to go.
Allison
28 Mar
28 Mar
2:50 p.m.
But if you REALLY want to do it right, you wind your own coil on a
shellacked oatmeal box.....or, a shellacked salt box.
All of mine used a germanium diode and a prewound coil, so there.
I'll shut up now.
Paul
From: Tony Duell <ard(a)p850ug1.demon.co.uk>
Paul Braun WD9GCO
Cygnus Productions
nerdware_nospam(a)laidbak.com
"A computer without a Microsoft operating system is like a dog without a bunch of
bricks tied to its head."
I read somewhere that a piece of coke (the fuel,
not the drug, OK
:-)) was used by POWs in the second world war as a detector. Using
much the same cats whisker arangement as with the galena crystal.
Might be worth
a
try.
I will work but you want to find a peice that has really been fired
and has a bit of rainbow color to it. IT's the contaminating oxides
and all that makes it work though germainium is better.
I would recomend getting the set working with a
germanium diode
first. Then, when you know the coil, tuning capacitor, headphones,
aerial, earth, etc are OK, try the home-made detector.
Good way to go.
Allison
3:01 p.m.
When I built mine, we (the CubScout pack) used toilet paper roll cores which we
varnished and then applied our magnet wire. We even went rock hunting to find
galena crystals to use. I don't remember any sort of diode ... there could've
been one, though ... that was nearly 50 years ago, after all.
Dick
----- Original Message -----
From: "Paul Braun" <nerdware(a)laidbak.com>
To: <classiccmp(a)classiccmp.org>
Sent: Wednesday, March 28, 2001 9:50 PM
Subject: Re: Crystal Radios (was Re: List spammer ID'd)
But if you REALLY want to do it right, you wind your
own coil on a
shellacked oatmeal box.....or, a shellacked salt box.
All of mine used a germanium diode and a prewound coil, so there.
I'll shut up now.
Paul
of bricks tied to its head."
From: Tony Duell <ard(a)p850ug1.demon.co.uk>
Paul Braun WD9GCO
Cygnus Productions
nerdware_nospam(a)laidbak.com
"A computer without a Microsoft operating system is like a dog without a bunch
I read somewhere that a piece of coke (the fuel,
not the drug, OK
:-)) was used by POWs in the second world war as a detector. Using
much the same cats whisker arangement as with the galena crystal.
Might be worth
a
try.
I will work but you want to find a peice that has really been fired
and has a bit of rainbow color to it. IT's the contaminating oxides
and all that makes it work though germainium is better.
I would recomend getting the set working with a
germanium diode
first. Then, when you know the coil, tuning capacitor, headphones,
aerial, earth, etc are OK, try the home-made detector.
Good way to go.
Allison
29 Mar
29 Mar
3:58 a.m.
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3:33 a.m.
On Thu, 29 Mar 2001, Tony Duell wrote:
My suggestion to use a ready-made diode (in the UK
I'd use something like
an OA81) is that you know that diode is good. You can then wind the coil
and wire up the rest of the set, knowing that if it doesn't work the
problem is not due to the fact you've not found a spot of the right
impurities in the crystal. When you've got it working, you can then swap
the diode for the crystal and catswhisker, knowing that if it doesn't
work the problem is with that.
That's cheating. What if you want to reproduce the experience of early
radio pioneers? They didn't have finely manufactured diodes :)
Otherwise there are too many variables IMHO.
And you'll be much the wiser when you do get it all figured out.
(I'm a purist :)
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
30 Mar
30 Mar
1:39 a.m.
Well, if the purpose of the crystal + (what we used was a safety-pin) is to
function as a diode, then is it still a crystal radio if a diode is used
instead?
Dick
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Thursday, March 29, 2001 10:58 AM
Subject: Re: Crystal Radios (was Re: List spammer ID'd)
>
> When I built mine, we (the CubScout pack) used toilet paper roll cores which
we
> varnished and then applied our magnet wire. We
even went rock hunting to
find
> galena crystals to use. I don't remember any
sort of diode ... there
could've
been one,
though ... that was nearly 50 years ago, after all.
The galena + catswhisker is a (poor-quality) diode.
My suggestion to use a ready-made diode (in the UK I'd use something like
an OA81) is that you know that diode is good. You can then wind the coil
and wire up the rest of the set, knowing that if it doesn't work the
problem is not due to the fact you've not found a spot of the right
impurities in the crystal. When you've got it working, you can then swap
the diode for the crystal and catswhisker, knowing that if it doesn't
work the problem is with that.
Otherwise there are too many variables IMHO.
-tony
4:27 a.m.
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6:51 p.m.
Depends on how hardcore a crystalset builder you are, I guess?
I've done it the hard way a few times for fun, but the results
were not lasting. Sometimes I also help children age ~10 to make
their first crystalset and in that case I'm happy to use of the shelf
components. For them it's important that they pull it off the first
time reliably. I have fun doing all of the above.
After all, somewhere in a ge-diode there is a crystal.....
Sipke de Wal
----------------------------------------------------------
"don't try to solve with words.....
..... what you can accomplish with a flamethrower"
----------------------------------------------------------
http://xgistor.ath.cx
----- Original Message -----
From: Richard Erlacher <edick(a)idcomm.com>
To: <classiccmp(a)classiccmp.org>
Sent: Friday, March 30, 2001 5:39 PM
Subject: Re: Crystal Radios (was Re: List spammer ID'd)
Well, if the purpose of the crystal + (what we used
was a safety-pin) is to
function as a diode, then is it still a crystal radio if a diode is used
instead?
Dick
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Thursday, March 29, 2001 10:58 AM
Subject: Re: Crystal Radios (was Re: List spammer ID'd)
> >
> > When I built mine, we (the CubScout pack) used toilet paper roll cores
which
we
> varnished and then applied our magnet wire.
We even went rock hunting to
find
> galena crystals to use. I don't
remember any sort of diode ... there
could've
been one,
though ... that was nearly 50 years ago, after all.
The galena + catswhisker is a (poor-quality) diode.
My suggestion to use a ready-made diode (in the UK I'd use something like
an OA81) is that you know that diode is good. You can then wind the coil
and wire up the rest of the set, knowing that if it doesn't work the
problem is not due to the fact you've not found a spot of the right
impurities in the crystal. When you've got it working, you can then swap
the diode for the crystal and catswhisker, knowing that if it doesn't
work the problem is with that.
Otherwise there are too many variables IMHO.
-tony
29 Mar
29 Mar
4:31 a.m.
On Wed, 28 Mar 2001, Paul Braun wrote:
But if you REALLY want to do it right, you wind your
own coil on a
shellacked oatmeal box.....or, a shellacked salt box.
Or a toilet paper roll, or a paper towel roll. The materials
abound. Of course, the real fun is to build the whole thing
with salvaged materials.
Piece of wood
nails
wire unwound from an old electric motor
cardboard tube from the kitchen
safety pin
pencil lead
razor blade
The hardest item is the earphone. Can be made, but not easily.
All of mine used a germanium diode and a prewound coil, so there.
I'll shut up now.
Modern technology. next thing you know you'll be wanting a variable
cpacitor for tuning and everything.
bill
--
Bill Gunshannon | de-moc-ra-cy (di mok' ra see) n. Three wolves
bill(a)cs.scranton.edu | and a sheep voting on what's for dinner.
University of Scranton |
Scranton, Pennsylvania | #include <std.disclaimer.h>
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8 comments
7 participants
participants (7)
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ajp166＠bellatlantic.net -
ard＠p850ug1.demon.co.uk -
bill＠cs.scranton.edu -
edick＠idcomm.com -
foo＠siconic.com -
nerdware＠laidbak.com -
sipke＠wxs.nl