Crystal Radio History

The crystal radio set was part of the history of amateur radio. These crystal sets were widely used in the 1920s and 1930s, ultimately being surpassed by vacuum tube / thermionic valve sets as the cost of tubes came down.

As the antenna provided the power for the headphones, every effort was made to optimise the crystal radios and as a result many different circuits were developed.

Check out this short video showing many sets and the crystal detectors used:

 

Very interesting. Thanks for sharing. I had crystal radios when I was a kid. The headphones were so loud at night that I had to disconnect them! There was a ham operator across the street and I could hear him operating AM (way back in the 50s), my first exposure to ham radio.

 

My very first electronic project was a crystal radio kit I got for Christmas back in the late '50s. The detector was a something like a 1N34A instead of a galena crystal, but after assembling that kit, and hearing our local AM station in the earpiece, I was hooked! Electronics became my predominant tech interest, and 50+ years later, it still is!

 

I just got done teaching this to my Cub Scouts last Spring...here is my blog https://www.blogger.com/blogger.g?b...sts;onClosedMenu=posts;postNum=1;src=postname

 

Around 1952-4 when I was 12-14 and growing bored with Lionel trains my dad retrieved his 20's crystal set from his parents house and gae it to me. It was a coil made from insulated bell wire with a strip where the insulation was sanded away, a solid copper or brass rod across the front, and a piece of spring brass and bent to be a wiper and the other end bent to ride on the rod; only pressure held it in place and I remember it traveling across a good part of the basement at times. This was attached to a board with the galena crystal and cats whisker assembly. Fahnestock clips were screwed down to provide for antenna and ground, plus the headphone tip jacks.
Living in the NYC/LI area of Nassau county and a long wire going up about 15' and out about 40' to a tree picked up a lot of the BCB, some police just above it and hams on AM on what I assume was 160M or just blasting thru from locals on 75. Sensitivity was decent when the crystals hot spot was found but selectivity was almost non existent. I still have the headphones but the rest is long gone. Over the next year I built a regenerative set from a Popular Science magazine article and soon had my Novice license. I had been listening to late 30's radios at my grandparents which included SW bands so had already discovered the hams and knew how much better vacuum tubes worked

Carl

 

I fell into the bad crowd over at Midnight Science. https://www.midnightscience.net/home.html Wasn't long before I was hooked. Started with the light stuff, simple kits, single tanks. You know how it goes, next thing I knew I was hooked. Homebuilt, mashing together designs from back-alley web sites and dark corners of the internet. Variometers, High Q coils, spider webs, loose coupled wave traps.

Staying up into the wee hours trying for DX reception. Canada was easy. CKLW and CHML in Ontario, both ran 50KW. Then got a taste of the midwest, WLS in Chicago, WHAS Louisville. Wanted more, build another set, learned how to do basket weave. Now WSB in Atlanta, WWL New Orleans.

Be careful with this stuff, next thing you know you'll become a ham.

 

"One radio at a time" Rich. Keep tuning, it gets better.

 

I loved the article - back from the time when radio really was magic.

 

My father gave me a fabulous book called The Boy Electrician when I was about 8 years old . . . he must have had it when he was a boy, as it was published in about 1928.

It gave full practical details (with diagrams) of how to make Crystal Sets, simple Valve Receivers, etc, as well as Telephones, X-Ray machines and lots more ! That's what got me interested in radio, and passed the exams and the Morse Test to get my Full Licence when I was 14.

We called them Wireless sets over here . . . right up until the 1960s ("I heard that record on the wireless . . . ")

Was it a purely English expression . . . or did you use it over in the USA too?

Also . . . I presume in the VERY early days you used WAVELENGTH of stations, rather than their frequency, right?

But at what point did you stop using Wavelength for Broadcast stations?

Here in the UK, we carried on using Wavelength for Medium Wave (= AM) stations almost to the 1980s (Stations would be on 257 metres, 261 metres, 208 metres, etc etc) . . . then everybody started referring to frequency instead.

Roger G3YRO

 

We need more Creeestals captain!

Hi Roger. Frequency had pretty much supplanted wavelength here by the late 1920s in most cases. The major impetus was that by then we actually had means of MEASURING frequency. HI!

Eric

 

I would also mention that shortwave broadcast stations still use BAND designations in wavelength...but precise frequency for the specific stations. Of course, radio is the first place where Americans had any contact with the metric system. HI!

 

Is IS sort of curious that we NEVER measured wavelength in yards here! I guess it just goes to show how international in nature ham radio has always been.

 

Memories indeed. In the early '60s I recall getting a Heathkit AM receiver in a box. I assembled it but my big brother found a couple of errors after which it pulled in WOR like gangbusters. It was the first time that I realized you could actually do this stuff at home.

 

Electronics has always been metric. I've watched other fields change--for example measuring coins went from grains and fractions of an inch to mg and mm. Too bad it has been such a slow process.

 

Built one as a kid to listen to my local 50 K AM radio station commemorating its anniversary on the air !
Was 13 and addicted to SWL and others in the day was shocked to hear so many AM Stations