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Modern Twist on Old Tech !

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Community Veteran
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Registered: ‎06-11-2007

Modern Twist on Old Tech !

For the past 3 weeks, I have been constructing a Crystal Set.... for those who do not know what one is..

https://en.wikipedia.org/wiki/Crystal_radio

 

Iit is a "simple radio"    Aerial, (100ft of bell wire) from house to end of garden...about 25 ft high.... Earth...metal spike in the ground outside of your window... join them to a "home wound coil"... add a "tuning capacitor" and a "crystal" or "diode" a pair of phones... and that was all you needed.. 

Lots of variations of the circuit,  appeared over the years...  making for improved selection and sensitivity .

My first crystal set was an "IVALEK" which my dad mounted on a shelf above my pillow, in my bedroom.... so I could listen to it, in bed... ( needed to be in a very quiet location to hear the weak signals)  and regularly listened to Radio Moscow.

I have made a few over the years....but nothing on this scale... I decided that I would make a "good looker"... and put a lot of thought and effort into how wires would connect the various parts, and I am very pleased with how it turned out,

Yes, it does work... I received the local radio station with a very strong signal, and also heard a German broadcast station vey faintly ... Now.. I am on a mission ...... going to make another for "experimental" purposes.. so will be just a piece of board, a few drawing pins for soldering points... and an ad-hoc way of wiring up the bits and pieces. !.. should be a bit of fun.....

 

 

 

 

P1090607.JPG

 

 

 

 

P1090609.JPG

 

(the item in the middle at the bottom, is a "home made" crystal holder with GALENA crystal, and a "cats whisker" )

 

 

P1090610.JPG

 

 

P1090612.JPG

 

 

Without the Diode ..... modern electronics, would not have progressed to the state we have.....


Old Tech... still works... !  

14 REPLIES 14
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Rising Star
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Registered: ‎24-10-2013

Re: Modern Twist on Old Tech !

Man that is super cool, i used to make crystal sets back in the early 70's nothing to match yours though only thing i could receive most nights was the BBC World service if i was really lucky might be able to pick up radio caroline. 

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Hero
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Re: Modern Twist on Old Tech !

@shutter 

Blimey this is posh!

My first crystal set didn't even have a tuning capacitor. Tuning was done with a slider that ran over the coil shich had the enamel removed from a strip on the outer surface. But it did have a germanium diode for rectification. I too could get radio moscow on it. 

I also remember playing with an original cat's whisker rectifier. This had a slider and knurled knob so that the cat's whisker could be adjusted to probe until the sweet spot on the crystal was found.

So what's next, a transistor radio built using a couple of 'red spot' mullard germanium transistors?

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Community Veteran
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Re: Modern Twist on Old Tech !

@Baldrick1   Ah yes... I remember them well ! ! ... Cheesy

bin there , dun that.... then moved on to mains powered ( build it yourself psu) and real valves... !

Smiley

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Hero
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Re: Modern Twist on Old Tech !

@shutter Wow, that takes me back.

My first crystal set was a home made Christmas gift from my uncle when I was ten. Something of a life changer really, sparking an interest in radio and ultimately communications in general. No surprise that it led to a career with the GPO/PO/BT.

I bought a book (more of a pamphlet really) on advanced crystal set designs, published by Babini IIRC.With improved selectivity and various coil designs, had great fun finding stations in Europe and sometimes further afield.

I have to say - from an appearance point of view, my sets were nothing like your engineering marvels - they're works of art!  😎

Bee Alert >> Spray safe >> Save hives
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Community Veteran
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Re: Modern Twist on Old Tech !

@shutter  that's very impressive, how long has that taken you?

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Aspiring Champion
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Re: Modern Twist on Old Tech !

@shutter  Can only say IMPRESSIVE !!!!Thumbs_Up

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Community Veteran
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Re: Modern Twist on Old Tech !

@shutter 

Very impressive and well designed.....

Amazing what can be achieved without spending lots of money.

I guess you got as much pleasure out of building it as using it.

😀

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Seasoned Champion
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Re: Modern Twist on Old Tech !

That is a piece of art,  my dad used to make radios so i grew up with pentode and superhetrodyne.. ( https://en.wikipedia.org/wiki/Superheterodyne_receiver ).

 

This is a piece of history,  and I had one

https://www.petervis.com/Radios/sinclair-micromatic-pocket-radio/sinclair-micromatic-pocket-radio.ht...

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Community Veteran
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Re: Modern Twist on Old Tech !

Looks a bit different to all the ones we made as kids.

Ours all worked but unlike yours looked "home made". That's a sort of back hand compliment to yours.

Of course that was a necessary evil for us kids then. Things were made out of scraps and any bits and pieces you could find.

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Seasoned Champion
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Re: Modern Twist on Old Tech !

Can still remember dad mixing 'shellac' flakes with methylated spirits to insulate and fix the copper coils in place - never realised then that shellac came from insects.

 

https://en.m.wikipedia.org/wiki/Shellac

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Grafter
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Re: Modern Twist on Old Tech !

Thats very neat. 🙂
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Re: Modern Twist on Old Tech !


@wotsup wrote:

never realised then that shellac came from insects.


 

Just think how many insects had to be squished up to make all those old shellac 78rpm records for gramophone use, they were probably very happy when the vinyl record was invented... 🤣

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Re: Modern Twist on Old Tech !

Thank you for all your kind words, guys.... It was a real pleasure to do the job, and I had to share the results. I am glad that you all appreciated it.

For those interested in making a crystals set,... you do not need to go to the extremes that I did....

    however, you should do a lot of reading up on the subject, as, although there are only 5 components .. you need to know which are the best values to use in which kind of circuit...

   Some circuits work better than others... and that is half the "fun" of making a crystal set..... the other half ( no not the missus ) is the frustration when it does not work ! .. ( on the other hand.. the missus does come into the equation then... cos she gets the brunt of your frustration! ! )

If you were to buy the cheapest of parts ... the cost would probably be less than £20.. which would have to include a pair of High Impedance Head phones...( 2,000 ohm or more...) modern phones are less than 8 ohms mostly.. and will need an "amplifier" circuit to be able to hear the radio.

I already had the parts to make the one in the pic... and... I already had a small unit that was a 12volt battery powered amplifier.. ( which I bought from Maplin a few years ago for another project) ... . which was lucky for me...because initially I thought the set was dead.... probably because I am deaf... and cannot use hearing aids with phones, as they cause feedback whistling... so.. without the hearing aids, i could not hear the very weak signals.

Once you have laid out the components on a piece of wood... using drawing pins for soldering points...( you could even draw the circuit on the wood, and wire it accordingly  )  and you managed to get it working... you can then mess about with different (physical) sized coils (diameters and lengths)  and using different wire gauges from thin to thickest.. some thick coils only need a few turns and can be "self supporting"...

Crystal sets work better "after dark"... due to the lowering of the F layer ( ionosphere ) which improves long distance reception of the continental stations.  !  You would also need to be in a very very quiet room... no background noise, to be able to hear those weak stations.

You WILL need a Long Wire aerial/antenna  which should really be about 100 ft ( 33mtrs ) and as high as possible... it is possible to run a wire around the room, at the ceiling height, and that would probably work for local radio station(s) .

 

 

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Aspiring Hero
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Re: Modern Twist on Old Tech !


@shutter wrote:

 

...  which would have to include a pair of High Impedance Head phones...( 2,000 ohm or more...) modern phones are less than 8 ohms mostly.. ...

Nice work @shutter

Ah yes, I remember when I made a crystal radio with 100% scavenged components many years ago (although it was nowhere near as posh as yours) I was able to use my Dads old RAF headphones similar to the set below.  I later rewired them for stereo.

I still have them somewhere, although last time I saw them the ear pads had mostly disintegrated.

headphones.jpg