Resonance: TK's Australia Radio: Variometer Galena Crystal Set
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- Опубліковано 15 чер 2014
- Copyright notice: Audio from AM broadcast radio stations is heard in this video as example material for _radio tuning demonstration_. This is Fair Use for educational purposes and the audio content is only incidental to the demonstration. No copyright infringement is intended nor is any occurring.
The Australia Radio is actually a very old design, but I found an excellent example at
crystalradioclub.co.uk/g4wpw.htm
My external antenna is just a long wire about 30 feet long strung out to the eaves of the house. The ground is a copper pipe driven about 4 feet into the ground in a damp spot under the window air conditioner.
The lead galena crystal is of very poor quality and was gotten over the internet as a "rock collection sample". I think a better quality crystal with good cubic fracture planes would probably work much better; at least it might be easier to find a good spot.
There is nothing special about the circuit, it is a basic crystal radio circuit, except I have a Green LED across (in parallel) with the audio output earphone connection.
When there is a strong station broadcasting at "daytime power" the LED will light up, and it does this without needing the crystal; it can be shorted and will still light the LED. The audio modulation doesn't appear to be necessary for LED lighting. I've had the LED glowing brilliantly but very little audio, and I've had, as in this video, very good loud clear audio but no LED lighting.
I played with the turn count to get the frequency in the range I wanted. Originally it was picking up a powerful station at 760 kHz that swamped everything, so I wound up taking some turns off to raise the frequency so that this station doesn't bleed over. But now I have the 1480 kHz station, also strong and nearby, bleeding over! However, I am ready to listen to CtC on a crystal set, like it should be heard. - Наука та технологія
I love your set design. It seems to work very well indeed, and I particularly like your self-designed and constructed variometer. I will follow your lead on the set I am designing. Excellent job!
ingenious coil antennae design reminding me of the newton motor concept hehehe..it seems the led lighting up story impresses me cos you said no station heard and it may also light up..that could mean the led is picking up ambient energy present not necessarily from the radio transmitters! its the kinda thing that impressed thomas henry morray,into making lightbulbs run from similar looking setups..almost holy grail of free energy!
Great video, the good old days
Very nice build and great demonstration. And if you consider that this was top technology only about 100 years ago, the rapid development of electronics begins to sink in. Back then almost everything could be built at home. Try that with a cell phone today. Greetings, Conrad
Very nice work, elegant design.
Thanks. Great demonstration.
I like the design, very artistic
What a beautiful creation! This looks like art to me! I love how you've taken bits and scraps and turned it all into technology. Please consider getting a shot of the led lighting up and post it! Thats a tiny demonstration of how Tesla wanted to transmit electricity wirelessly! Great work!
Thanks for watching and commenting!
a rejector circut would handle that nicely. lovely set . thanks for showing . friend of mine told me that when he was a young man , he learned that if one took a gerber (r) baby food jar and wrapped 90 turns on it and placed it between the antenna and the set , that would knock out most of the static .
What a neat project! Those "real" crystals are definitely tricky.
With my Selfmade Detektor with 2 coil coopler i Receiver in the Eavening Hour in AM 16 Stations,but since Years Not 🇩🇪From my Land!all ist finished.Matthias,old Hand Manufacturing coil Winder.😯
That's very interesting how keep inner wire from wrapping around inside
Good! Simple and functional.
That's really cool!
I love your radio,I wonder what your friends say when you tell them that your radio and you built it,nice job,I do wish you would tell us where you got your components from ,
Interesting design ,I thinking of useing a loop antenna so mine will be portable,I still collecting parts ,I have a ton of stuff already ,but I hopeing beaver magnetic wire wil! Work better
Very nice set. have you tried making a homebrew variable capacitor? I'm currently "in progress" on that one using cardstock and aluminum foil.
Great job........thanks for sharing.....do you have a wiring diragram??
Awesome!!😀👏👏
Variometers are fascinating, but I wish they had a wider tuning range. The 1480 station must be quite close to you. I noticed the catwhisker reception seemed very selective on that station once you got it in at good volume.
+sparkdetect
Yes, the transmitter and antenna are only about 3 miles away.
receiving a broad spectrum of stations all at once is a recipe for manic-depressive lunacy :P
Driving long distances at night, out of range of FM and tired of all my CDs I would often tune the AM to between stations and listen to the ghosts and static.
I still like to do this on occasion. Manic depressive lunacy? Sure, whatever makes you happy.
How to build a variometer (variable inductance)....any schematic ?
What are the values of the capacitors you used?
Do you think your hand capacitance might affect tuning?
Are you going to try any other old style diodes?
The rusty razor blade for example...
Probably. I've heard Gillette Blue blades are best, haven't seen them in many years.
TinselKoala i looked up some of the different things use on crystal sets-carborundum got a good rap.
I actually saw some old style blades at the supermarket last week, so they are still available.
NIce....where did you get the crystal...I would like to have one...
Ordered from Ebay, a chunk of lead galena. Not very good quality but there were a few usable pieces after I broke it up with a hammer.
www.tubesandmore.com/
Nice build, good look to it.
Try and place a variable air gap cap. where you have the coupling cap.
and put a finer point on that whisker
I think you forgot to install the variable capacitance capacitor
Lechoslowianin That must be why it works so well!
My question is what powers it
Electrons are in the air. All the power he is adding is for ampflication. Radio waves are the energy.
RED FORD - correct. But most of us are old-school, and just use passive high-impedance headphones without using a powered amplifier. The amplifier is useful, just as in the case of demonstrating the crystal set.
The radio station transmits tens of thousands of watts into the air. The receiving antenna develops a few millionths of a volt when it receives that signal. That is all the power the radio uses, and all it needs.
That's the south. Religion and sports fill the airwaves.
That is AM radio, no matter where you go.....oh, and right wing radical politics.
yawn...