Crystal sets? Any interest?

[boater sam]

I have met a guy who has lots of crystal sets in store, or so he says.  He is slowly emptying a container until he can get to them.
He also has a fair few plastic cased transistor radios.

Would anyone be interested?

[Murphyv310]

I'm certainly interested, even though there is less and less to tune into.

[Ed_Dinning]

Hi Yes, they could be of interest as I do work with schools and scout groups

Ed

[Murphyv310]

Would be of use for our radio Amateur club and a group we are going to encourage at the YMCA.

[boater sam]

The guy is of the opinion that these are antiques hence worth money  not giveaways. They are in Northwich.
I have not seen any of them. If there is any interest from anyone paying for these I can ask him to dig them out and go and see what they are and what condition.
I have bought several valve sets off him, these have been untouched and in reasonable condition.

[Mike Watterson]

So for exhibition rather than use and some (most) may be poorer than an 1N60, coil and ceramic disc as earpiece/capacitor with 10K Ohm.
They usually drove 2 x 2K earphones in series and needed a big aerial and earth. The galena crystals may have deteriorated.

Any 1899 to 1930s crystal set is really for display, though some may work. They used moving iron high impedance coils (2K). The crystal earpieces in 1940s to 1970s used a piece of crystal and foil diaphragm and were originally for hearing aids in the 1940s but used for covert radios. Like old crystal pickups they go off with damp, so the ones currently sold have a ceramic disc bonded to brass disc (as in beepers) and are about 2nF capacitance. A 10nF beeper disc seems to be upper limit. A beeper disk in small chamber with hole as an earpiece works well with about 10K load on the 1N60 diode (superior to OA81 or OA47). Adjust aerial coupling to coil for volume.

Various crystals and also oxidised copper discs used with an adjustable wire (the Cat's Whisker) were used as detectors. You can make copper oxide rectifiers with even a lighter. Old style tempered razor blades can work as can rusty bolts on a transmitter mast and then you get second harmonic!

Edit: The Wikipedia article describes the older crystal earpiece, the ones sold now are all the inferior ceramic disc like in a beeper.

[Mike Watterson]

Would be of use for our radio Amateur club and a group we are going to encourage at the YMCA.

Maybe 60 years ago, or 80 years ago. I think now something more advanced and portable, thus not needing 20m of washing line aerial is the thing.

Even in 1960s I wasn't impressed by a crystal set, though I built a few. Now and R1155, WS 88 on your belt, No 19 set and a C12 set was quite something else then. As were tape recorders.

[Murphyv310]

Would be of use for our radio Amateur club and a group we are going to encourage at the YMCA.

Maybe 60 years ago, or 80 years ago. I think now something more advanced and portable, thus not needing 20m of washing line aerial is the thing.

Even in 1960s I wasn't impressed by a crystal set, though I built a few. Now and R1155, WS 88 on your belt, No 19 set and a C12 set was quite something else then. As were tape recorders.

We are trying in both cases to get people and youngsters to see and feel how things have developed, a bit like what Lucien Nunes was trying to achieve.
I do have one late 20s crystal set and a nice big chunk of Galena I've had for donkeys.
Of course these days all folk think of is the sound of the till making money. So count me out.

[Mike Watterson]

Donkeys may prefer carrots?

You only need a little piece of Galena and sometimes you need a fresh surface. I've wondered how hard it would be to make a reasonable functional replica of the holder and the whisker adjustment. All the other bits are trivial. Glass spice jars better than empty loo-roll card tubes for Q as the card gets damp. The best Philips Superinductance coils used glass coil formers. An old cutlery box would make the bases for two crystal sets. The thing is to have the fun making and realise you don't need a 3D printer. I've wondered how easy it is to make a jig for a glass cutter and cut the glass "straws" now being sold. They, the bamboo and the stainless steel ones are a hazard to life if you trip and fall on your drink. Maybe paper is a better idea to replace plastic straws, or simply no straw. We only ever used them in school for the small milk bottles. One teacher thought it a good idea to put the milk crate on the radiator. The similar size Suki orange glass bottles used up paper straws too. They seemed to vanish when I was still in shorts for school.

[joebog1]

Of course these days all folk think of is the sound of the till making money.

Murphy thinks like me !!!. I wanted some 12AZ7 for a friend. Best price I could find was $150 for pulls!!!. Ka-chink!!!!.
Thats yanquee bucks too, so about $275 for me in real munny.

I still have the headphones, and have built many crystal sets, but almost all were made over 60 years ago.
I did make or help make 30 of them for a primary school teacher to teach his students. Unfortunately crystal earpieces for sound.
A poor mans "galena " can be sort of made by burning lead filings with sulpher. Sometimes it actually does make a crystaline substance.
Joe