I totally agree! The wonder to me lay in the fact that no batteries were required.
The energy that ultimately reached my ears as sound was carried by the radio waves themselves!
I totally agree! The wonder to me lay in the fact that no batteries were required.
The energy that ultimately reached my ears as sound was carried by the radio waves themselves!
Yes, I had one too as a kid. Built from a kit. It was completely fascinating, especially compared to the clockwork motors of my Meccano set.
No crystals were available where I grew up, but I managed to get hold of an 0A79 (germanium) diode instead.
My big headache was that I couldn't find / beg / borrow sensitive high-impedance headphones or earpiece, neither magnetic nor "crystal" (remember crystal earpieces? )
Climbing the tree nearest the window with a length of wire clutched in my teeth, I made a long outdoor antenna for the crystal radio, and that did the trick; when it was extremely quiet, at night, I could just barely hear the audio through the only earpiece I had, a low-impedance one that belonged to my dad's radio.
It shouldn't have worked at all, but it did - the local radio station was in the same town I lived in, so RF field strength was probably pretty good, and we were out in the sticks where it was very quiet. No traffic noises to drown out the quiet sounds in the earpiece.
Because the audio was so quiet that it was almost inaudible, I was keen to find a way to make it louder. That quickly led to learning how to add one transistor, one (bias) resistor, an input coupling capacitor, and a couple of D-cells borrowed from the family torch (flashlight) to amplify the audio signal from the OA79 detector.
The extra circuitry took away the magic of "free" music plucked out of thin air, but in exchange, I got the magic of having my very own radio, while my dad and two oldest siblings fought over the family Sony.
There were only two radio stations within receiving range. But they weren't very far apart on the AM dial. Picking out the weaker one by itself was a problem. So I learned that that amplifying the audio from the diode detector made for a louder radio, but one that was still very poor when it came to selectivity.
If radio was a wonder, can you imagine what people's first look at a TV - when the technology was brand new - felt like? Images somehow grabbed out of thin air at one location, and then transmitted somewhere else to magically re-appear?
And what about a "horseless carriage" in 1804, which was 218 years ago? I would have thought the sight of a machine moving by itself with no animals involved would have terrified and energized onlookers, but it seems Trevethick's engines were "...seen as little more than a novelty." How strange! https://www.historic-uk.com/HistoryUK/HistoryofBritain/Steam-trains-railways/
-Gnobuddy
My Uncle gave me a crystal set that was a kit, had a nice translucent dark green cover for the chassis.
It was fascinating that the radio waves alone would make for enough of an acoustic signal to actually hear it. A few years later, we lived far (40 miles) away from a favorite college station that had a weak signal anyways(5 mile range), but was able to pull it in by tramming in my rusty old antenna. I wonder if I would have even tried that had I not had that crystal radio? I had to walk 6 miles into town to buy some huge spikes to use to climb the power pole, so I had some conviction that it would work…
It was fascinating that the radio waves alone would make for enough of an acoustic signal to actually hear it. A few years later, we lived far (40 miles) away from a favorite college station that had a weak signal anyways(5 mile range), but was able to pull it in by tramming in my rusty old antenna. I wonder if I would have even tried that had I not had that crystal radio? I had to walk 6 miles into town to buy some huge spikes to use to climb the power pole, so I had some conviction that it would work…
OA79 across a telephone earpiece, we lived near the transmitter, only problem was we got all the stations. Never did put a variable cap as tuner.
Long wires, one as antenna, the other side of coil connected to ground.
I still have it somewhere.
Later used ordinary transistor radios, we used to listen to Radio Ceylon a lot on our Telerad valve radio, since childhood.
Sadly, TV and bad reception in cities took away that habit.
Now we get the same (old Hindi) songs on the local FM, so no need for SW.
Long wires, one as antenna, the other side of coil connected to ground.
I still have it somewhere.
Later used ordinary transistor radios, we used to listen to Radio Ceylon a lot on our Telerad valve radio, since childhood.
Sadly, TV and bad reception in cities took away that habit.
Now we get the same (old Hindi) songs on the local FM, so no need for SW.
I still keep as a cherished possession the broken ferrite antenna I used in my very first Crystal radio.
It had a very useful bonus feature, I found (by mistake of course) that if the tuning capacitor was NOT connected to the ferrite coil, I could hear very well 27MHz Citizens Band radio, guess by sheer chance some parasitic capacitance tuned the raw ferrite coil there.
It was used by "Estancia" owners who lived in the City to communicate with Gaucho workers there, typically 15 to 60 kilometers away ... or even further.
So everyday I listened to the chatter about cows needing a Vet, pigs needing more corn, tractor malfunctions, etc. but now and then "hey patrón! (boss), today we killed a cow/goat/pig and we are making a BIG Asado (BBQ) to celebrate xxxxxxx, come and enjoy!" or "Mrs xxxx made a few dozen Empanadas (meat pies) or even "some special lasagna" (we have tons of Italians around).
So I visited my neighbours who said "Hey Juan, we are going to the estancia today .... do you want to come with us?"
After 10-12 times of that happening like clockwork, one of them said "I noticed you miss NO celebration .... do you have a crystal ball or something?"
I tightly closed my lips and shrugged, didn´t want to kill the golden egg goose
It had a very useful bonus feature, I found (by mistake of course) that if the tuning capacitor was NOT connected to the ferrite coil, I could hear very well 27MHz Citizens Band radio, guess by sheer chance some parasitic capacitance tuned the raw ferrite coil there.
It was used by "Estancia" owners who lived in the City to communicate with Gaucho workers there, typically 15 to 60 kilometers away ... or even further.
So everyday I listened to the chatter about cows needing a Vet, pigs needing more corn, tractor malfunctions, etc. but now and then "hey patrón! (boss), today we killed a cow/goat/pig and we are making a BIG Asado (BBQ) to celebrate xxxxxxx, come and enjoy!" or "Mrs xxxx made a few dozen Empanadas (meat pies) or even "some special lasagna" (we have tons of Italians around).
So I visited my neighbours who said "Hey Juan, we are going to the estancia today .... do you want to come with us?"
After 10-12 times of that happening like clockwork, one of them said "I noticed you miss NO celebration .... do you have a crystal ball or something?"
I tightly closed my lips and shrugged, didn´t want to kill the golden egg goose
I grew up in a rural area west of Miami Florida. My first "crystal" radio came at a very young age, too young to accurately remember, somewhere between the paper clip meeting the wall outlet at age 4 and primary school. I got the idea from a real "galena crystal set" my grandfather showed me. You had to move the "cat's whisker" probe around on the "galena crystal" to get the best sound and slide a round metal bead back and forth along the coil for tuning. My "coil" was wire from a dissected transformer wrapped around a toilet paper tube slathered with Elmers glue. The "crystal" was a piece of pencil lead (graphite), a paper clip, and a rusty double edged razor blade. The earpiece was one of those high impedance ceramic things that I got off of a dead vacuum tube hearing aid. Since we lived about 1/2 mile from a 5KW AM radio station, it worked, barely. Unfortunately, it only picked up that station and they played "elevator music" for "old people" and I was about 6 years old. Now I am "old people" and I still don't like elevator music.
I would find out a few years later that a wire connected to the metal swing set in the back yard for an antenna, and another wire connected to a water faucet for a ground, would drive an 8 ohm speaker in parallel with a germanium diode to a volume level good enough for my parents' bedroom at night.
These experiments were the early beginnings of a long career in radio reception and transmission.
I would find out a few years later that a wire connected to the metal swing set in the back yard for an antenna, and another wire connected to a water faucet for a ground, would drive an 8 ohm speaker in parallel with a germanium diode to a volume level good enough for my parents' bedroom at night.
These experiments were the early beginnings of a long career in radio reception and transmission.
Nice.I still keep as a cherished possession the broken ferrite antenna I used in my very first Crystal radio.
It had a very useful bonus feature, I found (by mistake of course) that if the tuning capacitor was NOT connected to the ferrite coil, I could hear very well 27MHz Citizens Band radio, guess by sheer chance some parasitic capacitance tuned the raw ferrite coil there.
It was used by "Estancia" owners who lived in the City to communicate with Gaucho workers there, typically 15 to 60 kilometers away ... or even further.
So everyday I listened to the chatter about cows needing a Vet, pigs needing more corn, tractor malfunctions, etc. but now and then "hey patrón! (boss), today we killed a cow/goat/pig and we are making a BIG Asado (BBQ) to celebrate xxxxxxx, come and enjoy!" or "Mrs xxxx made a few dozen Empanadas (meat pies) or even "some special lasagna" (we have tons of Italians around).
So I visited my neighbours who said "Hey Juan, we are going to the estancia today .... do you want to come with us?"
After 10-12 times of that happening like clockwork, one of them said "I noticed you miss NO celebration .... do you have a crystal ball or something?"
I tightly closed my lips and shrugged, didn´t want to kill the golden egg goose
I remember building a crystal set with my Dad - he got all the parts from the engineering shop at his work. Then, a few years later when I was about 10 I built a 5 transistor portable radio kit "Transona 5" ( https://worldradiohistory.com/hd2/I...actical-Electronics-1967-11-OCR-Page-0029.pdf ) with a bit of help... That was brilliant. Then went on to get my amateur radio license, and have worked with RF one way or another ever since...
When I was about 10 or 12, I read an article in the local youth magazine: "A radio in a matchbox". I decided I have to build one of this little wonder with a germanium diode, a coil and a capacitor in it, that worked with a pair of WWII style headphones. This started my career in electronics 📻
