Self Powered 5 Transitor Hybrid X-tal Radio

[joellagace]

A tuned resonating L/C circuit can produce enough juice to power a small dc powered transistor radio frequency amplifier. I just built this circuit for fun and it works great! The resonating L/C circuit pulls in around 2.5 volts DC tuned at peek signal just enough to drive the amplifier circuit without needing batteries or any other external power source other its own self resonating oscillations.

See attached schematic.

[magpwr]

A tuned resonating L/C circuit can produce enough juice to power a small dc powered transistor radio frequency amplifier. I just built this circuit for fun and it works great! The resonating L/C circuit pulls in around 2.5 volts DC tuned at peek signal just enough to drive the amplifier circuit without needing batteries or any other external power source other its own self resonating oscillations.

See attached schematic.

hi there,

The only way you can get your circuit to work is to place it beside a table top powerful fm transmitter.

If you want the real deal like crystal fm radio using J-fet or diode (No battery needed for receiver) then check out this site.

http://billydiy.blogspot.sg/?view=magazine

I can't help you any further besides providing the link for you.

[joellagace]

Well, I guess you did not have as much luck as I had with a similar circuit then, I built this one and it works great here at home. You have to be within a couple miles of a high power AM station for this to work. If you live in the metro of a big city it should work just fine.

Your statement is half correct, On FM you would need to have the thing sitting next to a high power transmitter! at 100 mhz you really have to get very close to couple some of that RF. But on AM. at 1 mhz or below. Because of the nature of the extra long wave length. You can get away with pulling in a few volts as far as a couple miles away!

Few typos I notice on the shematic, Transistors Q1-4 or NPN 2N2222A ( I forgot a 2) You can use any general small npn type transistor. And C1 by the tuning meter should be C2. Just a simple label error. Still learning the software. And detector diode D1 can be of various types, You can experiment and find the better choice.

[Zeitmaschine]

Your radio is a combination of these two schematics: Free Electricity Out Of Thin Air

Reply was: »There is no free lunch.«

On the other hand, if getting hit by lightning during a thunderstorm is considered as »free lunch«, then this should be indeed also for free.

But why not using 4 diodes instead of the 4 transistors?

Regards

[joellagace]

Simply because I wanted to prove that for this application it works fine. A transistor in normal operation should not be used this way. The base can only handle a low voltage.

I'm not sure what your getting at with the comment "No Free Lunch" It is basic understandings of circuits.  A tuned L/C circuit will resonate to a nearby field of the source is near. That self oscillation from the tuned L/C can be rectified to DC. ( The basic Crystal Radio Set Is Perfect Example ) Many have been doing it for years. It has various usage and experiments over the years. Some can even power oscillators and small transmitters, On shortwave bands these can reach hundreds of miles away with just a few nano watts of radiated power. I did mention that you need to be tuned into a strong nearby AM radio station for this to work. No ridiculous claims but it does work as intended. A crystal radio that powers a basic amp stage with the circuits own self oscillation.