It's still possible to find the 1N34A in stores around Toronto. Not sure if a schottky diode would work, it was decades ago when I built my crystal set and it came with a 1N34A

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Bill
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Germainium diodes can easilly be replaced by small Schottky rectifiers which do a better job.

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Wimp!
My first one used a little chunk of galena, imbedded in lead(?), with a "catwhisker" that I had to move around to find a sensitive spot.

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Ron

 

what do you think the voltage drop was for a crystal and cat wisker? more or less than a germanium diode? and what about a rusty razorblade and wisker?

 

Yes Roff,
I remember Gillette blades used as detectors. they have a similar coating in those days.

Thanks to Hero999.

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Sarma.

 

That was high tech, I just wanted to listen to music when my parents thought I was sleeping. Moving the whisker around under the blankets might have looks suspicious.

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Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

It will be more than Germanium diode and also inconsistent.

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Regards,
Sarma.

 

I think you can use a lot of different materials, so long as the contacting surfaces have a lonlinear V-I curve. I once detected a local radio station with a contraption that consisted of two pieces of a tin can (plated steel, actually) bent into L shapes and nailed to a board, with a piece of fine wire laid across them, as in the drawing below. Needless to say, it was highly microphonic, which was probably what I was actually trying to achieve. I remember I had it connected to some long wires that went to a friend's house. We were trying to get some sort of intercom going. The wires acted as an antenna, and the oxide on the wire/tin as the detector. The result was quite a surprise, as you can imagine.

Attached Images

strange detector.PNG (7.1 KB, 6 views)

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Ron

 

That's nothing. When I was 10 years old my family was camping and for fun I decided to try driving the family car around the campsite (without permission of course). Well I backed it into a tent pole that my dad had secured with a long piece of steel wire. Then I pulled forward and banged into the neighbor's trailer. For some reason the tent pole, with wire attached, had got wedged into the rear bumper and dragged along, and with the same luck, the sheet metal on the neighbor's Airstream had made an unholy union with the rusty bit of fender up at the front of the car. As the adults ran up to the site of the carnage, they stopped in their tracks as they clearly hear "Moon River" emanating from the aluminum wall of that Airstream.

When I finally recovered from my punishment, I had acquired a new and perhaps twisted interest in the magic of radio.

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RadioRon

 

Hmmm...

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Ron

 

I once heard of a fellow that could hear the sounds of AM radio stations when he got close to the transmitters, seemed like the cause was a filling in one of his teeth was a good detector.

I sure do remember the galena crystal and the cat whisker for the detector.
I also remember when the CK722 transistor was available commercially. As I recall one cost me about $4.00. To a teenager in the early 50's that was a lot of money.

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I saw the CK722 transistor used in the projects in the electronics magazines of times gone by.
Since you were a teenager in the 50's and i was just a kid then you are a little older than me.

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I had two CK722's. i think I waited until they were US $0.99. One of them I used to make a regenerative AM radio that worked great. The other one never worked well, but I may have damaged it shortly after I got it.
I bought a few of them on Ebay about 9 or 10 years ago, but I'm danged if I know where they are now.

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Ron

 

how can a detector alone make sound without a transducer?

 

Are you referring to a particular post?

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Ron