Radio without batteries

    Can a radio receiver consist of less than 10 parts and work without batteries?

    Yes, it can: detector radios are very simple and can work, receiving power only from radio waves. In this article I will describe how you can do such a thing with your own hands, spending no more than an hour on all the work! ;)

    What is a good detector radio?

    Firstly, this receiver works without batteries. Secondly, all the necessary parts cost about 10-15 rubles, and there are plenty of them in the old technology. Thirdly, everyone can assemble the receiver, regardless of the existing skills (reading and working with a soldering iron are welcome :-)

    But there are also disadvantages. Most likely, only one station will be well received, drowning all the others (usually it is the “Mayak”). The second disadvantage is low power. It will be enough to give a normal sound from the headphone, but nothing more.

    One way or another, such a receiver can be a good helper in the country, when there are power outages or it is difficult to buy batteries. I have in the country house there are already 4 such receivers throughout the house, my grandfather will not be glad of them =)

    What do we need for assembly?
    • Fixed capacitor 190-500 PF
    • Capacitor 1000-2000 PF
    • Any diode (except light)
    • Copper wire with a diameter of 1-0.1 mm
    • Cylinder with a diameter of 10 cm (for example, a can of coffee)
    • Newspaper
    • A metal pin about 30 cm long for grounding
    • A small speaker, for example from an old disk telephone

    Here is what the Oganov detector radio looks like:

    image

    We start with the simplest one - grounding. We drive a metal pin into the ground, after attaching a wire to it (for security reasons, it is better not to use the heating battery as grounding). And remember that the better the grounding, the better the reception of the station. It is best to establish grounding on the side of the house where the sun least falls, where the earth is always damp. The end of the grounding is carried out into the house and fixed to the corresponding terminal of the receiver.

    The next step is to create an antenna. I had it under a roof, about 10 meters long. You can make it, for example, from copper wire. Practice shows that with an antenna 10 meters long, only one station will be received, but loudly. With an antenna length of 1-3 m, it will be possible to catch other stations, but they will all be very hard to hear.

    Next, we take up the coil. The coil consists of two equal parts, 20 turns each (this is for receiving medium waves, and for receiving long ones you need to wind 60 turns). How to make a coil? We take something round with a diameter of about 10 cm (for example, a can of coffee), glue it with a double layer of newspaper. The first layer is attached to the bank with tape, the second is loosely screwed onto the first. In this case, the coil after winding will be easy to remove. Now we carefully wind the copper wire - coil to coil. Between the two parts of the coil we leave 5 centimeters of wire, and also do not forget to leave about the same amount of wire at the inlet and outlet. After you have wound the coil, it should be wrapped with electrical tape in two layers along the turns. And after removing from the can - also wrap across. Yes, we will no longer need the newspaper, we can get rid of it with a clear conscience!

    Finally, let's start assembling the receiver!

    The diagram above can be simplified to the following form:

    image

    In this form, it is easiest to solder, and in the end there will be less wires. Carefully clean all the parts and solder them to each other! 8-) We attach a coil, antenna, grounding, earphone and, if done correctly, we enjoy a clean and even reception of the Beacon! =)

    If you want to tune to a different frequency, or the reception quality is far from ideal - take a coil of thicker wire.

    The adjustment is made by moving one part of the coil relative to another. For the most accurate tuning, you can take several variable capacitors that replace C1, tuning them you can tune in to the station as accurately as possible.

    What the receiver will look like - depends only on your imagination! Due to its small size, it can be packaged in almost any container. In the photo, one of my 4 receivers is a wall-mounted model with a toggle-switch for turning off the power (the radio and coils are in a black box, the white wire is grounding and the antenna, and the black wire goes to the earphone :) There were also more compact options, but their photos , unfortunately no)

    image

    In general, everything, I hope that this material will be useful to someone =)

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