I have been a professional electronics technician since 1973, with 36 years as an avionics technician,and I have been studying electronics history as well as keeping up on the newest tech, and this is the first time I have heard of this system! I don't understand how I could have missed it, as I was most interested in the DeForest Audion and its first use in telephone amplification, as well as being used to generate RF, once they discovered it could oscillate.... But I do not recall any mention of this electromecanical amplification system in my histories. But the ability to take a small voltage and change it into a mechanical motion in order to cause a large voltage change, simulates what a tube or transistor does, without the mechanical change. Fascinating!
There's another type of high gain amplifier which uses a transducer to vibrate the point of a probe point dipped in acidic liquid. The probe circuit has a much higher voltage.
I've spent most of my life repairing electronics for underground Coal mining...Most of their telephones until recently used Carbon Microphones in the handsets and I always wondered if a solonoid and carbon pile could work as an amplifier and never knew that this thing was actually done with apparently great success at the turn of the century...Thank You for telling me this
Heck, I didn't even know double crystal sets were a thing until watching your video. Thanks for restoring those jewels and demonstrating and documenting here.
Ah this British Thompson-Houston crystal set.... Yes, you would think this is some clever attempt to do some sort of full wave rectification of the RF to increase the power to the headphones, BUT IT IS NOT. It is simply two identical galena crystal holders and cats whiskers with a switch to select one OR the other. Seems hardly worth it eh? More of a gimmick to attract attention in the local wireless shop.
@@RadioHist Was probably helpful if both were adjusted to work and the one in use happened to dropout, you might have a chance to switch to the other and not lose the current listening content. Not necessarily a scam. One maybe for galena and the other for a different material. I believe shipping and military versions may have had backup detectors. Others had both Cats-whisker and Perikon types.
@@Ross-z1n On the BTH crystal set I don't see mention of different minerals. Both detectors have wire chucks expresley for cats whiskers. There is no provision for mounting a second holder for a Perikon (two mineral ) junction..... I have not searched for articles analyzing this particular receiver.
This is the coolest thing I've seen on here in a long, long time and I watch a lot of UA-cam. Thanks for your diligent effort in bringing these back to life.
Thank you this was a really interesting and well presented video about an almost forgotten piece of technical history. Even better to see and hear it working.
I had one of those crystal sets, the two top binding post where it say earth is intending use with a external coil long wave coil by removing the shorting bar and inset a long wave coil.
My first Job was with S.G.Brown ltd, just before the name was removed from current history. never saw any of their old products laying around the factory. 😞
Also love the crystal set A/B crystal change over knob, can continue listening while at same time fiddle about with getting other crystal ready to try out.
That's very interesting ... had never seen that amplification technique before, and I've been aware of carbon granule 'mics' for quite some time now, as used in landline telephony and by Motorola on their early 2-way radios. Thank you for the actual demonstration too!
Thank you for your very well researched and presented video and thank you for rescuing and documenting this fine equipment. May I point you and your followers to the Porth Curno Museum of World Telegraphy in Cornwall. They have a magnificent collection of repeaters and other telegraphic kit. The Museum is a must see and a short walk to the beach where the United Kingdom connected to the Empire. Best wishes from the UK.
Wow, an electro-mechanical audio amplifier. So, basically a transformer that can self adjust to audio frequencies, thus amplification was similar to stepping up ac voltage using a ratio of windings. Old tech like this is very intriguing,
Hi fascinating i did something similar back in the sixties with a balanced armature GPO earpiece and a carbon mic insert all mounted in a thick cardboard tube it worked quite well after a lot of fiddling around...
This is absolutely fascinating. Thank you for your hard work and for your time in demonstrating and explaining this technology. Do the carbon granular amplifiers themselves emit any low level audio? I’m not really sure I’d call a carbon granular amplifier “solid” state due to the mechanisms at play, but it is so interesting and certainly wasn’t at all like a tube or transistor amplifier! What a unique technology! 73!
Yes, they can be quite noisy, and not just as a form of distortion - there is an audible hiss that may also include pops, crackles, whistles and so on.
Seen an article in an old electronics electrical magazine from the early 50s or late 40s, had construction plans.ithink they were using on a crystal set.
I had some Brown headphones once but they were much later series. I traded them off but I have several pairs of Baldwins which are fairly sensitive for one tube radios or crystal sets as compared to Brandes or something similar.
Very interesting, my home here in California was built in 1929, I often wonder what it was like to live here back then 😊 Especially the cars that slept in my detached garage 😇
I thought that active signal amplification took off only with the invention of vacuum tubes.Does the Marconi magnetic detector belong to the same family of " non fully electronic" amplifiers?
Brilliant video, very interesting. I had no idea this technology existed. People were so inventive back then. Well done for managing to get these working. Never thought i would ever hear sweet home Alabama on a crystal set! If I may make a suggestion. If you don't already do so, take the best resolution photos you can of the adverts and instructions stickers, as they are almost lost historic documents. I couldnt read the small print on one of them. I appreciate that you might just use them as literal background for the video, but they are interesting in their own right. If you are able to save them for posterity, i would hope that you try to do so. On that subject of the adverts. Isnt it refreshing to go back to the days when adverts actually told you something about the product, rather than just having a few minor celebrities dancing around and possible quoting false science😊
It is a $30 item off e-Bay. I needed an inexpensive TUNABLE unit that I could power from a cell phone power bank. I use this unit in a demonstration setup at hamfests and exhibitions where I may not have AC mains. Also such venues are almost certainly going to have some strong interference somewhere on the band I need to avoid. AND you ought to be aware that this particular unit is capable of exceeding FCC limits buy a little bit. Of course I have no interest in interference of licensed services in the area. And I know how to avoid that.
@RadioHist Looking at it does appear capable of 'overloading the crystal' of you know what I mean. As I understand legal side is generally all around the world as long as such a signal is undetectable outside the premises then it's legal. By 'undetectable' this includes not being overtly getting heard and attract attention.
Has this been tried under actual antenna conditions? A crystal set typically has a loaded output of a few tenths of a volt with a good antenna and strong station. I wonder if it would actually work for real! I tried to build one of these but in every case the "amplified output" was worse than simply connecting to the speaker directly! Oh well.
Oh yes. The Heathkit CR-1 was connected to a single wire with a total length of 50 ft. including the lead-in and less than 20 ft. off the ground. And the orientation of the wire is 45 and 60 degrees off from optimum.
I don't think so. Most communication work was done with headphones in those days. These carbon amps had low sensitivity only for boosting audio to a horn speaker from a signal that would be loud on any good set of headphones.
I've fooled around with carbon contact mechanical amplifiers a bit, with appropriately noisy success in most cases. There's a short video of one such setup on my channel.
The selection on the Brown Type V was indeed a contemporary (1925) British recording:.... The first year of electrical recordings in the UK I think. That, in my opinion, gave a better demonstration of what would have been live performances at the wireless station 1924 or earlier recordings were acoustic. (Except for some rare non-commercial experimental work.) The modern country music clips help to demonstrate why old radios sound differently than 'back in the day'. The audio from the microphone to the transmitter output is almost always highly manipulated these days. The Henry Busse clip is from a 1935 transcription service disk.
I hope no one else sounds like me😁 I have a terrible impromptu speaking style.... I have to record, process, edit and speed up my real voice to take some of the pain out of listening to my narration. Not everyone can be a Lowell Thomas or Edwin R. Murrow....
Unfortunately the presentation was not formatted corrected to 16x9 when uploaded to UA-cam The Audubon submitted to AT&T in 1913 was not suitable for use as an amplifier. You underestimated the work AT&T scientists and engineers did to make a successful amplifier.
ouch!! >_< ... granted if you were listening like this 100 years ago you were sh!tting in tall cotton... but my god, those speakers are more than a little 'sharp' and actually quite painful at points... would love to see what the amplifiers themselves look like on a dual trace scope comparing input and output...
Better yet, a spectrogram of in and output ... a sine-sweep from 100 Hz to 5 kHz even ... plotted,log amplitude and frequency scales (you get the idea).
@@RadioHist At one time, there was a PC-based sound card utility called "Speaker Workshop" that could accomplish this, I used it to characterize a 10 meter radio that sounded horrible due to incorrectly-sized audio stage coupling/shaping capacitors, giving it a muffled-sounding quality on-the-air, but that was better than 10 years ago now ...
The amount of patience required to restore delicate equipment like that must be astounding. Excellent work!
I have been a professional electronics technician since 1973, with 36 years as an avionics technician,and I have been studying electronics history as well as keeping up on the newest tech, and this is the first time I have heard of this system!
I don't understand how I could have missed it, as I was most interested in the DeForest Audion and its first use in telephone amplification, as well as being used to generate RF, once they discovered it could oscillate.... But I do not recall any mention of this electromecanical amplification system in my histories.
But the ability to take a small voltage and change it into a mechanical motion in order to cause a large voltage change, simulates what a tube or transistor does, without the mechanical change. Fascinating!
There's another type of high gain amplifier which uses a transducer to vibrate the point of a probe point dipped in acidic liquid. The probe circuit has a much higher voltage.
I think we have have found the basis for the name "Transfer-Resistor" to "Transistor"?
We need to acknowledge how hard these folks worked to invent and build things which we take for granted today.
Agree
Those great (overwhelmingly) white men!
I've spent most of my life repairing electronics for underground Coal mining...Most of their telephones until recently used Carbon Microphones in the handsets and I always wondered if a solonoid and carbon pile could work as an amplifier and never knew that this thing was actually done with apparently great success at the turn of the century...Thank You for telling me this
As a electronics repair tech (now retired) I love old technology like this. Thank you for sharing this.
Heck, I didn't even know double crystal sets were a thing until watching your video. Thanks for restoring those jewels and demonstrating and documenting here.
Ah this British Thompson-Houston crystal set.... Yes, you would think this is some clever attempt to do some sort of full wave rectification of the RF to increase the power to the headphones, BUT IT IS NOT. It is simply two identical galena crystal holders and cats whiskers with a switch to select one OR the other. Seems hardly worth it eh? More of a gimmick to attract attention in the local wireless shop.
@@RadioHist Was probably helpful if both were adjusted to work and the one in use happened to dropout, you might have a chance to switch to the other and not lose the current listening content.
Not necessarily a scam.
One maybe for galena and the other for a different material. I believe shipping and military versions may have had backup detectors.
Others had both Cats-whisker and Perikon types.
@@Ross-z1n On the BTH crystal set I don't see mention of different minerals. Both detectors have wire chucks expresley for cats whiskers. There is no provision for mounting a second holder for a Perikon (two mineral ) junction..... I have not searched for articles analyzing this particular receiver.
This is the coolest thing I've seen on here in a long, long time and I watch a lot of UA-cam. Thanks for your diligent effort in bringing these back to life.
Another great video. I really love them. They're so in depth you go to such effort to publish something great and you always do.
Thank you this was a really interesting and well presented video about an almost forgotten piece of technical history. Even better to see and hear it working.
Amazing restoration work! Excellent video!
I had one of those crystal sets, the two top binding post where it say earth is intending use with a external coil
long wave coil by removing the shorting bar and inset a long wave coil.
I have one as well. It has the BBC approved/certified stamp on the lid. Someone cut two notches for the antenna and headphone wires.
Robert Did amazing job restoring this ! thanks for the great video guys .
My first Job was with S.G.Brown ltd, just before the name was removed from current history. never saw any of their old products laying around the factory. 😞
Also love the crystal set A/B crystal change over knob, can continue listening while at same time fiddle about with getting other crystal ready to try out.
I saw that too! Reckon the crystals could be a bit fiddly, and it would be a nice feature to have an A - B comparison capability too!
This is amazing!
That's very interesting ... had never seen that amplification technique before, and I've been aware of carbon granule 'mics' for quite some time now, as used in landline telephony and by Motorola on their early 2-way radios. Thank you for the actual demonstration too!
Thank you for your very well researched and presented video and thank you for rescuing and documenting this fine equipment. May I point you and your followers to the Porth Curno Museum of World Telegraphy in Cornwall. They have a magnificent collection of repeaters and other telegraphic kit. The Museum is a must see and a short walk to the beach where the United Kingdom connected to the Empire. Best wishes from the UK.
Wow, an electro-mechanical audio amplifier. So, basically a transformer that can self adjust to audio frequencies, thus amplification was similar to stepping up ac voltage using a ratio of windings. Old tech like this is very intriguing,
Thanks for excellent information re Repeater Brown Amplifies I enjoyed the podcast,Ian from Australia,
Fascinating video and peek at old tech. I often wondered how they pulled off early amplification before tubes or transistors were on the scene.
If a flux capacitor is biased just right it will give very good amplification!
Magnetic amplifiers were used in certain applications starting in the early 20th century.
Hi fascinating i did something similar back in the sixties with a balanced armature GPO earpiece and a carbon mic insert all mounted in a thick cardboard tube it worked quite well after a lot of fiddling around...
Starting at about 13:51 in this video:
I bet folks 'back in the day' would be rather amazed to hear _Lynyrd Skynyrd._ 😊
This is absolutely fascinating. Thank you for your hard work and for your time in demonstrating and explaining this technology.
Do the carbon granular amplifiers themselves emit any low level audio?
I’m not really sure I’d call a carbon granular amplifier “solid” state due to the mechanisms at play, but it is so interesting and certainly wasn’t at all like a tube or transistor amplifier! What a unique technology! 73!
As far as I know, all carbon microphones are noisy when compared to capacitive or dynamic elements.
Yes, they can be quite noisy, and not just as a form of distortion - there is an audible hiss that may also include pops, crackles, whistles and so on.
Seen an article in an old electronics electrical magazine from the early 50s or late 40s, had construction plans.ithink they were using on a crystal set.
Seeing the DC bias makes me wonder if a higher than audio bias frequency might have been an area to explore.
Fantastic! Cook to know now that such devices exist.
I had some Brown headphones once but they were much later series. I traded them off but I have several pairs of Baldwins which are fairly sensitive for one tube radios or crystal sets as compared to Brandes or something similar.
Interesting technology
Beautiful, I can smell the varnish from here. Have you experienced the "Auxetophone" ? That would certainly fill your workshop!
I've seen the UA-cam videos..... Wild! to say the least.... Lucky the collector that can boast one....
Very interesting, my home here in California was built in 1929, I often wonder what it was like to live here back then 😊 Especially the cars that slept in my detached garage 😇
I thought that active signal amplification took off only with the invention of vacuum tubes.Does the Marconi magnetic detector belong to the same family of " non fully electronic" amplifiers?
Brilliant video, very interesting. I had no idea this technology existed. People were so inventive back then.
Well done for managing to get these working. Never thought i would ever hear sweet home Alabama on a crystal set!
If I may make a suggestion. If you don't already do so, take the best resolution photos you can of the adverts and instructions stickers, as they are almost lost historic documents. I couldnt read the small print on one of them. I appreciate that you might just use them as literal background for the video, but they are interesting in their own right. If you are able to save them for posterity, i would hope that you try to do so.
On that subject of the adverts. Isnt it refreshing to go back to the days when adverts actually told you something about the product, rather than just having a few minor celebrities dancing around and possible quoting false science😊
Very cool info 😎 🆒️ 😎
love the medlum wave signal generator at 7:20 , making simulated aerial/earth
It is a $30 item off e-Bay. I needed an inexpensive TUNABLE unit that I could power from a cell phone power bank. I use this unit in a demonstration setup at hamfests and exhibitions where I may not have AC mains. Also such venues are almost certainly going to have some strong interference somewhere on the band I need to avoid. AND you ought to be aware that this particular unit is capable of exceeding FCC limits buy a little bit. Of course I have no interest in interference of licensed services in the area. And I know how to avoid that.
@RadioHist Looking at it does appear capable of 'overloading the crystal' of you know what I mean. As I understand legal side is generally all around the world as long as such a signal is undetectable outside the premises then it's legal. By 'undetectable' this includes not being overtly getting heard and attract attention.
Think electronics experimented was the magazine had an article on this with a crude plan to build.
Funciona lo probé más o menos aora trabajo a un dispositivo igualmente espero tenerlo listo con un radio galena
KD4HSH, this is JW6RQX. Great programme.
Has this been tried under actual antenna conditions? A crystal set typically has a loaded output of a few tenths of a volt with a good antenna and strong station. I wonder if it would actually work for real! I tried to build one of these but in every case the "amplified output" was worse than simply connecting to the speaker directly! Oh well.
Oh yes. The Heathkit CR-1 was connected to a single wire with a total length of 50 ft. including the lead-in and less than 20 ft. off the ground. And the orientation of the wire is 45 and 60 degrees off from optimum.
Is there any references that list the carbon grain sizes commonly utilized in these devices?
Smaller that table salt and much more irregular. I've not seen specifications.
Were these used for communication receivers much ?
I don't think so. Most communication work was done with headphones in those days. These carbon amps had low sensitivity only for boosting audio to a horn speaker from a signal that would be loud on any good set of headphones.
I've fooled around with carbon contact mechanical amplifiers a bit, with appropriately noisy success in most cases. There's a short video of one such setup on my channel.
Pity you didn't have some contemporary audio to compare.
Sounds like a fun project to try and duplicate.
The selection on the Brown Type V was indeed a contemporary (1925) British recording:.... The first year of electrical recordings in the UK I think. That, in my opinion, gave a better demonstration of what would have been live performances at the wireless station 1924 or earlier recordings were acoustic. (Except for some rare non-commercial experimental work.) The modern country music clips help to demonstrate why old radios sound differently than 'back in the day'. The audio from the microphone to the transmitter output is almost always highly manipulated these days. The Henry Busse clip is from a 1935 transcription service disk.
I could have sworn you were George Thomas, W5JDX, by your voice. George does the Amateur Logic YT vids. 👍
I hope no one else sounds like me😁 I have a terrible impromptu speaking style.... I have to record, process, edit and speed up my real voice to take some of the pain out of listening to my narration. Not everyone can be a Lowell Thomas or Edwin R. Murrow....
Unfortunately the presentation was not formatted corrected to 16x9 when uploaded to UA-cam
The Audubon submitted to AT&T in 1913 was not suitable for use as an amplifier. You underestimated the work AT&T scientists and engineers did to make a successful amplifier.
ouch!! >_< ... granted if you were listening like this 100 years ago you were sh!tting in tall cotton... but my god, those speakers are more than a little 'sharp' and actually quite painful at points... would love to see what the amplifiers themselves look like on a dual trace scope comparing input and output...
Better yet, a spectrogram of in and output ... a sine-sweep from 100 Hz to 5 kHz even ... plotted,log amplitude and frequency scales (you get the idea).
@@uploadJ Don't have the time or instruments to make such an evaluation. Someone else will have to bear the torch.
@@RadioHist At one time, there was a PC-based sound card utility called "Speaker Workshop" that could accomplish this, I used it to characterize a 10 meter radio that sounded horrible due to incorrectly-sized audio stage coupling/shaping capacitors, giving it a muffled-sounding quality on-the-air, but that was better than 10 years ago now ...
@WirelessMuseum >>> Great video...👍
Solid state?
Well, not hollow-state ...
W PRL U TELEFONY FUNKCJONOWALY GORZEJ NIZ W USA W 1919 ROKU BOSTON