Crystal Set Query
 

Hi all

Cam someone please help me with a query I have about an old crystal set I
used to own.

When I first came to live in Melbourne (1970s) my parents purchased for me a
small crystal set.at a local, now long gone, toy store. As I recall the set
was manufactured in England although I may be wrong on this point.

It was housed in a small plastic box (red?) and from memory was about 2
inches long and maybe an inch wide and high.

Inside the box was a small wound coil (about 1/4" diameter) around a thin
cardboard tube. There was a ferrite rod inside this which could be slid back
and forth within the tube by means of a small rod that stuck out of the end
of the ferte rod and protruded from the end of the box. This was used for
tuning stations. There was also a piece of wire coming from the box with an
alligator clip on the end. This was the antenna and by attaching it to a
long piece of wire one could receive stations. There was also another piece
of twin wire protruduing from the box which went to a crystal earpiece so
that you could listen to stations.

Aside from this I think there were only two other components - a diode and a
capacitor as I recall which formed the crystal set circuit. Unfortunately
the set is now lost after so many years.

This was my first introduction to radio and despite moving on to bigger
radios and getting my ham license, this example of a crystal set has always
stuck in my mind as being a particularly simple but efficient example of
electrical engineering. I now have a young son of my own and would like very
much to buy one of these sets.

Does anyone know who manufactured these sets and whether they are still
available to be purchased?

cheers Peter VK3PB

We used to build them with 1N34A diode, capacitor across the headphones,
and a coil wound on a toilet paper tube, with taps on the coil
that you'd clip an allegator clip to, for tuning.

Assemble atop wooden board.

There were some with an actual cat whisker instead of the diode,
but we went the modern way mostly.

The project is mostly winding the coil, many turns of enameled wire,
and scraping bits of it clear of enamel for the allegator clip
landing spots.

Another tuning method was a slider over the coil but it never
seemed like that would be very easy to get to work reliably.

Antenna and ground across the live portion of the coil.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

That sure brings back some memories S. I made one with a piece of Galena and a cat whisker and a headset. I didn't have any tuning, just a wire for an antenna and a wire to connect to ground - and it worked ! Later I got a diode, as that seemed to work better, but I also managed to get a transistor to work as detector as well simply by the way the leads were connected. It was great fun experimenting. Dad bought me one similar to what you describe, but it was red and white plastic in the shape of a rocket, and it had a metal rod that you could push in or pull out to tune. It had a piece of germanium that slid in and out of a coil. Your son would love it s.mm

Peace +

"Ron Hardin" wrote in message ...
We used to build them with 1N34A diode, capacitor across the headphones,
and a coil wound on a toilet paper tube, with taps on the coil
that you'd clip an allegator clip to, for tuning.

Assemble atop wooden board.

There were some with an actual cat whisker instead of the diode,
but we went the modern way mostly.

The project is mostly winding the coil, many turns of enameled wire,
and scraping bits of it clear of enamel for the allegator clip
landing spots.

Another tuning method was a slider over the coil but it never
seemed like that would be very easy to get to work reliably.

Antenna and ground across the live portion of the coil.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

Was the radio shaped like a "rocket"?
Like:
http://www.tompolk.com/radios/rocket.html
or:
http://home.earthlink.net/~wb5rex/xt...osrockets.html
There is a company making a reproduction.
I will dig out their name and URL tonight.
Terry

wrote:

Was the radio shaped like a "rocket"?
Like:
http://www.tompolk.com/radios/rocket.html
or:
http://home.earthlink.net/~wb5rex/xt...osrockets.html
There is a company making a reproduction.
I will dig out their name and URL tonight.

I had a couple of those rocket radios in the late 50's early 60's.

dxAce
Michigan
USA

No but the radio is very similar

I think I would almost prefer a rocket radio for my son if they are still
available! They look way cool!

cheers Peter


wrote in message
oups.com...
Was the radio shaped like a "rocket"?
Like:
http://www.tompolk.com/radios/rocket.html
or:
http://home.earthlink.net/~wb5rex/xt...osrockets.html
There is a company making a reproduction.
I will dig out their name and URL tonight.
Terry

Ron Hardin wrote:

We used to build them with 1N34A diode, capacitor across the
headphones,
and a coil wound on a toilet paper tube, with taps on the coil
that you'd clip an allegator clip to, for tuning.

We still do! And they still work great!

They're not hard to construct with inexpensive readily-available items.
There are several good websites with tips and hints for simple
construction, and they're great fun. Try making one!

Bruce Jensen

Ron Hardin wrote:

We used to build them with 1N34A diode, capacitor across the
headphones,
and a coil wound on a toilet paper tube, with taps on the coil
that you'd clip an allegator clip to, for tuning.

We still do! And they still work great!

They're not hard to construct with inexpensive readily-available items.
There are several good websites with tips and hints for simple
construction, and they're great fun. Try making one!

Bruce Jensen

I bought a crystal radio set from an ad I saw in a Popular Mechanics
magazine in 1947.It worked great too.
cuhulin

peter berrett wrote:

Does anyone know who manufactured these sets and whether they are still
available to be purchased?


many pages out there. A Google search for

crystal radio sets

turned up many sites. Some of them are below:

http://www.clarion.org.au/crystalset/

http://www.thebest.net/wuggy/

http://www.midnightscience.com/

http://www.midnightscience.com/kits.html

http://journeytoforever.org/edu_radio.html

http://www.schmarder.com/radios/crystal/

http://www.electronics-tutorials.com...-radio-set.htm

http://www.streettech.com/archives_DIY/crystalSet.html

http://store.yahoo.com/mbaciu/rocrad19512.html

http://www.bluesky.com/warren/radios/rocketradio/




mike

My father was telling me recently about how he built capacitors from scratch
when he was a boy. He scrounged broken bits of glass and alternated them
with pieces of tinfoil from gum wrappers. Together with some wire leads they
formed a capacitor for use in homebrew crystal radios. He used the large
oatmeal boxes for coil forms, and transducers from old telphone handsets for
the earpiece. A galena crystal and safety pin was used for the detector, but
I don't know where he came upon the galena.

Guy Atkins
Puyallup, WA USA


"Ron Hardin" wrote in message
...
We used to build them with 1N34A diode, capacitor across the headphones,
and a coil wound on a toilet paper tube, with taps on the coil
that you'd clip an allegator clip to, for tuning.

Assemble atop wooden board.

There were some with an actual cat whisker instead of the diode,
but we went the modern way mostly.
SNIP

The modern reproduciton that I have was made by DaMart Company.
I found this web site in Engalnd:
http://www.greatgizmos.co.uk/damert_company_page_1.htm

Rocket Radio (Reference #D4025)
It receives radio signals without using batteries! In the late 1950's,
kids learnt that the magic of radio could be achieved without batteries
through an ingenious gizmo known as the Rocket Radio. Now it's back! By
attaching the antenna/ground wire and tuning the nose cone, a handful
of AM stations can be received and heard through a crystal earphone. An
informative booklet will help curious minds understand the science
behind radio transmissions and crystal diodes. For ages 8 and up.

The show a blue one, but mine is red.
My sister tore mine up back in 1960.
She bought me one in 2001 for my 50th birthday.
My orignal was blue but I didn't complain.
It works pretty well, but I found a site that has some improvements,
but I can't find the $#%^ URL right now. I never got around to
making them, after all why complicate something simple that really
works. When I find the URL I will post it here as a new post.
Terry

Terry
:

"peter berrett" wrote in message
...
No but the radio is very similar

I think I would almost prefer a rocket radio for my son if they are still
available! They look way cool!

cheers Peter

http://cgi.ebay.com/ws/eBayISAPI.dll...482786 4&rd=1

I think you'd be better off getting one commercially first. Then experiment
with it so you can make your own. It's much less frustrating that way.

Purists insist on using a chunk of galena and a "cat's whisker" for the
detector, but you can substitute a plain old 1N34 germanium diode to
accomplish the same thing without all that trouble of having to poke around
to find a "hot spot" on the chunk of galena.

There are different ways to accomplish tuning. You can have a variable
coil, or a variable capacitor. Big variable caps can still be found, though
not new, and they're easier to work with. Smaller variable caps can be
salvaged from junked transistor radios.

It's been said that "A dollar in the antenna is worth ten in the receiver."
That holds true. String up as much long wire as you can for your antenna.
And also make sure you have a good earth ground. That will really help.

After you get all this done, please let us know what you hear!!!!

Matt J. McCullar, KJ5BA
Arlington, TX

-=jd=- wrote:

So out of curiosity, off I went "a-googling". Oddly enough, the first
couple of sources that listed the Rocket Radio for sale were "SOLD-OUT".
Hmm... Perhaps it was a popular item this past Christmas season?

Then, I tried:
http://home.earthlink.net/~wb5rex/xt...newrocket.html

He's got them for $13.95.

I'm sure there are other sites that may have them...

Good Luck with it!

-=jd=-

Here's a froogle search sorted low to high price

http://froogle.google.com/froogle?num=20&hl=en&lr=&c2coff=1&safe=off&tab=wf& scoring=p&q=rocket+radio+crystal&btnG=Search+Froog le

$9.95 (plus shipping) seems typical.

http://www.crystalradio.net/misc/rocket/index.shtml

Good Luck!
Mike
KC6SEG

"peter berrett" wrote in message
u...

Hi all

Cam someone please help me with a query I have about an old crystal set I
used to own.

When I first came to live in Melbourne (1970s) my parents purchased for me
a
small crystal set.at a local, now long gone, toy store. As I recall the
set
was manufactured in England although I may be wrong on this point.

It was housed in a small plastic box (red?) and from memory was about 2
inches long and maybe an inch wide and high.

Inside the box was a small wound coil (about 1/4" diameter) around a thin
cardboard tube. There was a ferrite rod inside this which could be slid
back
and forth within the tube by means of a small rod that stuck out of the
end
of the ferte rod and protruded from the end of the box. This was used for
tuning stations. There was also a piece of wire coming from the box with
an
alligator clip on the end. This was the antenna and by attaching it to a
long piece of wire one could receive stations. There was also another
piece
of twin wire protruduing from the box which went to a crystal earpiece so
that you could listen to stations.

Aside from this I think there were only two other components - a diode and
a
capacitor as I recall which formed the crystal set circuit. Unfortunately
the set is now lost after so many years.

This was my first introduction to radio and despite moving on to bigger
radios and getting my ham license, this example of a crystal set has
always
stuck in my mind as being a particularly simple but efficient example of
electrical engineering. I now have a young son of my own and would like
very
much to buy one of these sets.

Does anyone know who manufactured these sets and whether they are still
available to be purchased?

cheers Peter VK3PB

Ron Hardin wrote:

There were some with an actual cat whisker instead of the diode,
but we went the modern way mostly.

I had a crystal set in the 1960's that used a real galena crystal which
was mounted in a small metal cup. The cup served as one of the
electrical connections for the crystal. The crystal was embedded in some
kind of metal which I assume was poured into the cup in a molten state.
Could it have been lead?


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Matt J. McCullar wrote:
Purists insist on using a chunk of galena and a "cat's whisker" for the
detector, but you can substitute a plain old 1N34 germanium diode to
accomplish the same thing without all that trouble of having to poke around
to find a "hot spot" on the chunk of galena.

In a homebrew crystal radio, I tried a chunk of galena, but it did not
work as well as an iron pyrite ("fool's gold") crystal. For a "cat's
whisker", I used a small gold-plated safety pin.

In my experience, the old high-impedence headphones (which typically have
Bakelite ear pieces and a headband made of spring steel covered with cloth
or leather) work much better than the cheap in-the-ear kind found on
modern crystal radio kits.

As mentioned earlier, http://www.midnightscience.com has some great
crystal radio info.

--Leigh Marrin/KM6JE in Santa Barbara, Calif.

Thanks for the link. The radio will make a great present.

cheers Peter


"-=jd=-" wrote in message
...
On Wed 12 Jan 2005 08:47:21a, "peter berrett"
wrote in message :

No but the radio is very similar

I think I would almost prefer a rocket radio for my son if they are
still
available! They look way cool!

cheers Peter




Hmmm... I've noticed them in Cracker Barrel restaurants recently. I just
checked their website (http://www.crackerbarrel.com) but, they don't list
it online. I want to say they were about $10.00.

So out of curiosity, off I went "a-googling". Oddly enough, the first
couple of sources that listed the Rocket Radio for sale were "SOLD-OUT".
Hmm... Perhaps it was a popular item this past Christmas season?

Then, I tried:
http://home.earthlink.net/~wb5rex/xt...newrocket.html

He's got them for $13.95.

I'm sure there are other sites that may have them...

Good Luck with it!

-=jd=-
--
My Current Disposable Email:

(Remove YOUR HAT to reply directly)

On Thu, 13 Jan 2005 00:21:42 -0500, starman wrote:
I had a crystal set in the 1960's that used a real galena crystal which
was mounted in a small metal cup. The cup served as one of the
electrical connections for the crystal. The crystal was embedded in some
kind of metal which I assume was poured into the cup in a molten state.
Could it have been lead?

You can use solder, but Woods Metal is better as it melts in boiling water
and you can make your mould in wood or plastic. I've just made some crystals
using it for a reproduction 1920s style xtal set.

--
Cheers,
Stan Barr stanb .at. dial .dot. pipex .dot. com
(Remove any digits from the addresses when mailing me.)

The future was never like this!

Thanks to everyone who replied to my query about Crystal Sets. I have firm
plans to purchase a rocket radio for my son. I have built my own crystal
sets in the past but I think for a present the rocket radio is hard to beat.

That aside I have another query for which I would be grateful if people
could provide a response.

When I used to build crystal radios I found that my voltmeter would show a
small voltage when measuring the output of the circuit. For some time I have
toyed with the idea of building a crystal set transmitter which seems to me
to be a logical extension of the idea of a crystal set reciever.

First one would tap a large coil in parrallel with a variable capacitor and
attached to a long wire. Several taps would extract the strongest stations
in the vicinity. Each signal extracted would then be rectified by the use of
4 diodes so that a pulsating DC current is generated. Finally the various DC
currents would be combined and smoothed out to provide a power souce for
the transmitter stage.

Next, a simple single transistor crystal locked transmitter would be built
which would be powered by the dc current mentioned earlier. This could be
keyed on and off to give a morse signal.

Finally, and separately, a short wave crystal radio could be built for
reception on the frequency of the transmitter stage

Is such a project doable or is the power that you would extract out of the
air too low to drive transistors etc?

cheers peter





"peter berrett" wrote in message
u...

Hi all

Cam someone please help me with a query I have about an old crystal set I
used to own.

When I first came to live in Melbourne (1970s) my parents purchased for me
a
small crystal set.at a local, now long gone, toy store. As I recall the
set
was manufactured in England although I may be wrong on this point.

It was housed in a small plastic box (red?) and from memory was about 2
inches long and maybe an inch wide and high.

Inside the box was a small wound coil (about 1/4" diameter) around a thin
cardboard tube. There was a ferrite rod inside this which could be slid
back
and forth within the tube by means of a small rod that stuck out of the
end
of the ferte rod and protruded from the end of the box. This was used for
tuning stations. There was also a piece of wire coming from the box with
an
alligator clip on the end. This was the antenna and by attaching it to a
long piece of wire one could receive stations. There was also another
piece
of twin wire protruduing from the box which went to a crystal earpiece so
that you could listen to stations.

Aside from this I think there were only two other components - a diode and
a
capacitor as I recall which formed the crystal set circuit. Unfortunately
the set is now lost after so many years.

This was my first introduction to radio and despite moving on to bigger
radios and getting my ham license, this example of a crystal set has
always
stuck in my mind as being a particularly simple but efficient example of
electrical engineering. I now have a young son of my own and would like
very
much to buy one of these sets.

Does anyone know who manufactured these sets and whether they are still
available to be purchased?

cheers Peter VK3PB

The old Raytheon ``What to do with your CK722'' project book has
a crystal-set-powered transistor radio, taking the DC from a crystal
set output and using it to power a CK722 amplifier.

They used the same station for both, however, which was a major
conceptual error. You want to use a local for the power, to
amplify a more distant station.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

Thanks Ron

cheers Peter

"Ron Hardin" wrote in message
...
The old Raytheon ``What to do with your CK722'' project book has
a crystal-set-powered transistor radio, taking the DC from a crystal
set output and using it to power a CK722 amplifier.

They used the same station for both, however, which was a major
conceptual error. You want to use a local for the power, to
amplify a more distant station.
--
Ron Hardin


On the internet, nobody knows you're a jerk.