This amazing never heard of this before or if I did I have forgotten. Always interesting to see how great minds work. An excellent demo video and i learned something new .
So far I had only seen these on drawings, and never at work. Actually was unaware they could detect AM, thought it was just for telegraphy. It works pretty well I must say, and your is not just good working, it's also beautifully made. Maybe it would work even better if one would make one of these detectors with audio tape and casette player parts (motor, playback and erasing heads), might give it a try myself. I am more used to catwhiskers, but this looks very interesting. Both detectors are amazing, couldn't expect any less from you anyways, sir. Best regards.
Esperimento condotto abilmente con un'apparecchiatura perfetta costruttivamente e tecnicamente , mediante la quale si dimostra come il detector magnetico è in grado di rilevare non solo segnali telegrafici ma anche radiofonici. Le mie più vive congratulazioni.
The irony is that although this kind of looks like an old tape recorder it isn't. Well only in the sense the wire holds on to a bit of residual magnetism in one direction for a while. You mention the crystal detector which was being tried at the same time. The sensitivity was a bit hit and miss and ships tend to roll around and vibrate. This worked and had a trained operator. The Titanic had a Fleming valve but they were fragile and not used even when installed. Philips had been on the job for nearly 10 years already. No doubt succumbing to us oldies reluctance to embrace new fangled technology. Difficult I know to imagine most of the world in 1912 had no idea how anything worked and the cognoscenti were complaining about built in redundancy. By the way, whenever my local ATM goes down the XP start screen appears while it reboots.?2022
Thank you for posting this video. Please post some details- How many primary and secondary turns in the "Pick-up coil?" Where did you get the iron wire? Is the antenna tuner a series circuit, with the pick-up primary at the Earth end or the Antenna end, or is it a parallel circuit, tapped for the pick-up primary? Thanks very much!
This is a beautiful, clever apparatus created by Marconi that demonstrate he had real scientific knowledge and was not simply an empirical inventor ripping off the ideas of others! Having said that, since this contraption was invented before application of AM radio(?), how did he demonstrate it? Did he use it to pick up radiotelegraph signals? Were radiotelegraph signals modulated with sound back then, and if so, how at a time before electronics?
+Jeffrey314159 Wireless telegraphy signals were generally provided by spark transmitters which used an induction coil to provide the high voltage needed,so the spark would be timed by the interruptor of that coil, providing a form of crude modulated tone.
Yes, that and the 'white noise' produced by the crude method of electric arc sparking. This is why these devices were useless for voice transmissions. Do you knowledge of any exceptions, such as the Poulsen Arc Transmitter? The first apparatus to transmitt the human voice, that I know of, was a high frequency(50 to 100 kilohertz) alternator, not arcspark and not electronic, and this was before WW1
Excellent video, very impressive workmanship. Would you have plans or information on building both the magnetic detector and antenna tuner, as shown in the video.
I'm always strangely surprised to hear modern broadcasts to come out of these... I'm always expecting to hear news of the sinking of the Lucitania or some trad jazz or something. ;)
Can I ask if you have done a video on the replica of Marconi's short-range radio transmitter-receiver that you built? I'm referring to the one talked about in the video where you built the type C triode valve. Many thanks.
@@glasslinger Thank you very much, you are an inspiration to my own attempts at building and repairing pre/post WW2 valve based electronic equipment, thanks again and keep up the amazing work, A Fan!
wow more than one way to skin that rectafire problem that is cool how about a demo of the transcever you made the big trieode tube for with the feed throw on the side thank you grate job marycrismass to you
Magnetic detector - Wikipediaen.wikipedia.org › wiki › Magnetic_detector Developed in 1902 by radio pioneer Guglielmo Marconi from a method invented in 1895 by New Zealand physicist Ernest Rutherford it was used in Marconi wireless stations until around 1912, when it was superseded by vacuum tubes. It was widely used on ships because of its reliability and insensitivity to vibration.
Marconi used the magnetic detector for his wireless telegraphy. Since the detector converts radio signals to audio frequency, it can also be used to receive radio broadcast
Sorry I meant to say the irony is that Cape Race 1912 did record high speed wireless Morse on wax cylinder and transcribe by playing slower. According to operator memoir anecdote.
Hi friend i love Marconi magnetic detector but impossible to find !!! please have you got schematics i want do one by myself ! many thanks friend bests regards Jeremy
If the radio operator on the Californian had remembered or know to wind the clockwork motor on the magnetic detector then he might have heard the distress calls from the Titanic.
Actually, he went to bed just before the excitement started. This is something a ships radio operator would not do after the Titanic. Most of our radio procedure today comes out of the Titanic investigation.
No, this is not like a 'tape recorder', if it were so, then the pickup or read coil would be wound around the second or output magnet. This works by DEGAUSSING!
+Jeffrey314159 It works on the principle that an alternating magnetic field can affect the coercivity of the wire's hysteresis, so the field of the primary coil(which is connected to the antenna) changes how far the wire has to travel into the field of the second magnet before it's magnetism aligns with it. The current induced in the secondary coil is larger the closer to it the actual flip of the field occurs, and so it changes too. So, the wire is not degaussed, it's field is flipped.
Alright, that makes sense, but it does not explain, for me, how this method directly coverts radio frequency energy to an audio frequency energy. Is this also the result of the hysterisis? When Marconi made this device he was creating a means for detecting low frequency(
+Jeffrey314159 Much in the replies above is accurate. My reference to a tape recorder was meant only to indicate a magnetic media passing magnets to change the magnetic pattern in the media. The actual conversion of RF to AF happens when the magnets are positioned very carefully to just saturate the wire in one direction. The modulated RF then drives the wire in and out of saturation at the modulation frequency. The low frequency mentioned above is very accurate. The sensitivity of the device is abysmal! It took modern electronics in the amplifier to get enough gain to make it pick up 610khz signals on the AM band. I do not think Marconi stole the idea from Tesla, as was hypothesized in another comment . I have not found any info in Tesla's work that he ever worked on such a contraption!
Really good demonstration. There's a loaf of nonsense written by half knowledgeable folks with simulated Titanic Morse code. The Barkhausen effect random domain switching noise would not have been as audible in 1912 without the high amplification used here. The noise of steam being released from funnels outside was making it impossible for Jack Philips to hear signals.
This detector was not invented by Marconi but was developed by Marconi. It was invented by Ernest Rutherford from New Zealand who was born and lived not far from me in Nelson NZ.
Magnetic detector - Wikipediaen.wikipedia.org › wiki › Magnetic_detector Developed in 1902 by radio pioneer Guglielmo Marconi from a method invented in 1895 by New Zealand physicist Ernest Rutherford it was used in Marconi wireless stations until around 1912, when it was superseded by vacuum tubes. It was widely used on ships because of its reliability and insensitivity to vibration.
Ha, ha, ha! I know you are being funny, but actually he could have tried a crystal detector. At the time crystal detectors were totally new and experimental but they were around if you knew who to talk to!
@@glasslinger There always come a point in any technology development when you switch from one approach to another. The magnetic detector came from Ernest Rutherford so had a big name behind it. Maybe he just stuck with what he knew at that time? I realise that the crystal detector had advocates like Braun & Bose, so it should also have been given due consideration - more so than the magnetic detector in hindsight. Now when did Radiospares start in the UK...? :-) By the way, your polished wooden constructions are a work of art in themselves!
***** Right. And he stole the idea of the battery from Mr. Volta, and the idea of the capacitor from Mr. Leyden. Reality: No technology develops in a vacuum. Each inventor builds upon those before. Marconi happened to be the one guy who figured out how to put all the pieces together and make a radio.
***** Woulda, coulda, shoulda. Tesla DIDN'T make a working radio, and Marconi did. And Marconi did NOT steal Tesla's patents. He may have used some of the devices/concepts, but that is not criminal theft. Patents, in any case, have a limited life and must be defended. If Tesla failed to defend his patents then he, defacto, accepted the use by others, regardless of the circumstances. And again, all technology builds upon the past. Your arguments are childish and you need to be more precise in your use of language.
well fuck you tesla said it himself let him work he uses 11 of my patents and he did make a radio he even made a remote controlled boat marcony is a scammer and look up the patent for the radio tesla is the owner of that patent "Marconi won the Nobel Prize for physics in 1909 [source: Nobel Prize], further fueling the rivalry with Tesla. In 1915, Tesla sued the Marconi Company for patent infringement to no avail. Marconi had won. Or had he? In an ironic twist of fate, Marconi's company sued the U.S. government in 1943 for patent infringement during World War I. But the case never made it to court. Instead, to avoid the lawsuit altogether, the U.S. Supreme Court upheld patent 645,576, thus restoring Tesla (who had died a few months earlier) as the inventor of the radio. Nevertheless, many people still tend to think of Marconi as the father of the radio."
So Marconi was the successful step-father and Tesla was the bumbling brilliant sperm donor who failed in business and died a lonely crazy man. Marconi had the vision, engineering and skill to make things happen and Tesla didn't.
