How to make a transmitter and telegraph by yourself using electronic components?

A transmitter or a telegraph machine, under amateur conditions, it is not difficult to make an experimental model. But the challenge is whether you need an experimental or practical transmitter.

If it's experimental, you can try both:

The first is the cable telegraph experiment. It is recommended to use IC installation, and it is easy to succeed. The components that need to be bought are:

NE555 and LM386 each have two pieces, and several resistor-capacitance elements and electric bonds. NE555 is used to make an oscillation circuit on each circuit board, LM386 is used to make a successful amplifier circuit, and the same circuit is used to make two boards. With a long wire (double core) connected to two circuit boards, you can encode and send the report, which is mainly a small test to exercise the listening ability of the code.

Second, wireless telegraphy, low-power can use several 9018 transistors to form a high-frequency oscillation circuit, take the power supply on and off for CW modulation, and the other board also uses 9018 to form a super-regenerative receiving circuit or simply use an FM radio (which requires audio modulation for transmission). Basically, there can be a communication distance of 50 meters. This is mainly to exercise the ability of radio mini-production.

If it's practical, there's little point in having cable, and you can't get into the country's telegraph network. Wireless requires more power and belongs to the category of small radio stations. It's more complicated to make, but it's not too difficult for people with radio experience, and the key point is that wireless communication is regulated, and you need to get a license before you can do it.

But if you're getting to the point of getting a license, you don't have to ask that question in it. So, if you're interested in communication, you might as well make a little experiment as I suggest first, get started first, and improve your interest and hands-on skills.

If you're a fan of radio communication, there are two more forums to check out: the Ore Radio Forum and the Radio Enthusiasts Forum.

The downstairs is too detailed, no need to say more! Hehe.

Ore and Guangtan often go!

Materials required: double-sided tape, contact switch, light-emitting diode, cardboard 1, find a piece of cardboard with moderate hardness, fold the shape according to the figure below 2, connect the wires respectively, pay attention to the positive and negative poles of the battery and buzzer (the red wire on the battery is connected to the red wire of the buzzer).

3. Connect the wire to the contact switch and wrap it with electrical tape to ensure that there will be no leakage 4. Embed the contact switch on the red sponge pad, and the white sponge pad is attached to the outside of the red sponge pad 5. Paste double-sided tape under the battery box and buzzer respectively and stick it on the cardboard. Pressing the switch will hear the sound of a tick while the diode will glow.

Nowadays, people love this What can be done is what can be done, that is, the transmission distance is limited, and the materials required for a few meters are: a square wooden board (the size is as big as the palm), a 6V stacked battery, a flashlight bulb (or a 6V motorcycle turn bulb), a reset key switch (old-fashioned doorbell button), several self-tapping screws, a number of wires, a roll of double-sided tape, and a section of thin wire.

The steps are as follows:

1. Glue the battery to the corner of the template with double-sided tape;

2. Fix the key switch (code button) on the template with self-tapping screws;

3. After welding the electrode with a wire, fix the small bulb on the empty position of the wooden board with a thin wire and self-tapping screws;

4 Finally, the battery, switch, and small light bulb are all connected in series, and a simplest transmitter is ready. Principle: When the button switch is pressed and released instantaneously, the current of the battery lights on or off the small bulb through the circuit, and the instantaneous current pulse signal can be received by the radio.

The effect is better when the reception frequency of the radio is adjusted to the right time.

** of not written by themselves The watchtower owner is satisfied.

Materials required: double-sided tape, contact switches, light-emitting diodes, cardboard.

1. Find a piece of cardboard with moderate hardness and fold it into shape according to the picture below.

2. Connect the wires respectively, pay attention to the positive and negative poles of the battery and buzzer (the red wire on the battery is connected to the red wire of the buzzer).

3. Connect the wire to the contact switch, and wrap it with electrical glue to ensure that there will be no leakage.

4. Embed the contact switch on the red sponge pad, and the white sponge pad is attached to the outside of the red sponge pad.

5. Paste double-sided tape under the battery box and buzzer respectively and stick it on the cardboard. Pressing the switch will hear the sound of a tick while the diode will glow.

I don't know how simple you want to be and how far you can transmit it.

1. Find a battery, a wire, and a radio. Turn the radio to a place where there is no station and turn the volume up to the maximum. Short circuit the battery with a wire.

At the same time as the short circuit, the radio will make a sound, and then it will be decoded according to the rule of the number of rings. The transmission distance is about 10 meters.

2. A single set of components: it is better to have a radio modification, which is relatively simple. First of all, a radio is the receiving part of a telegraph.

A non-polarized capacitor is used to connect the base of the transistor to the volume potentiometer with the middle tap of the volume potentiometer. Then connect a button switch (button for sending information) at both ends of the solenoid coil. Press the button and the code will be sent.

It can be used for receiving if it is not on time. But to disconnect the capacitor. The transmission distance is about 100 meters.

3. Do it yourself, single set: frequency processing part: crystal oscillator (for transmission), too sleepy, don't write.

As far as is known, shortwave radio stations are now digitized. In fact, it is like a Bluetooth keyboard - no cable, and it can be at a certain distance from the computer host.

It is envisaged that two computers can be used as short-wave radio stations to form a local network with long-distance wireless networks, which is the modern short-wave radio -- telegraphs.

It is a telegraph from the Second World War era, which has the meaning of nostalgia. There is no practical significance.

A single point: just use a headset + a battery!

The plug of the earphone leads out two wires, one is connected to one electrode of the battery, and the other wire is used to tap the other electrode of the battery - the electric key, and the earphone will make a clicking sound - the report is received.

This is also the most original telegraph design!

Battery, electric keys, electromagnets - with armature, connecting wires - if you want to be farther away, the wires are longer.

To complicate a little more, use an audio oscillator + speaker instead of headphones.

To get a little more complicated, just send an email!

At this time, the actual transmission in the network is still tick-0,1 :)