How to make a walkie-talkie?
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Many have portable walkie-talkies. Buy them can be in the store, however, the operation of such walkie-talkies is often hampered by ground obstacles. But it is possible to assemble a stationary walkie-talkie with a small power and with an increased range of action. Consider how to make a walkie-talkie with your own hands. To do this, you need:
- Resistors - AC 47 kΩ and 10 kΩ
- Transistor P416
- Condenser 0.022 mF (2 pcs.)
- Capacitors 4700 pF, 0.033 mF, 100 pF, 33 pF, 51 pF
- Trimmer capacitor 4-15 pF (2 pcs.)
- Throttle (L2) 20-60μs
- Telescopic antenna
- Carbon microphone
- Copper wire, cross section 0.5 mm (40 cm)
- Battery power (9-12V)
- Switch SA1
- A piece of Getinax
- Power switch
- Textolite for mounting panel
- Sheet of aluminum
- Mounting wire
- Soldering iron
- Accessories for soldering
First, you need to make a U-shaped chassisfrom an aluminum sheet. It will need to locate the controls. In this case, the power supply unit should be taken already ready from the radio, radio or TV. It should give a constant anode voltage of 150-250V, as well as a heating voltage of 6.3V. Then, in accordance with the transceiver circuit, you need to assemble the walkie-talkie:
The coil of the transceiver circuit mustbe made of a copper wire having a diameter of 1 mm. You need to take a bare wire, and even better - silver plated. It should be wound on a rod having a diameter of 12 mm. The coil should contain 4 turns with a tap in the middle. In this case, the coil of communication with the antenna is located on top of the coil of the circuit and contains 1-2 turns of the same wire. The chokes should be wound on the resistance VS-0.25. They should contain 0.5 m of PEL-0.15 wire.
As for the tuning capacitor C, itscan be taken with a ceramic dielectric, however, it is better if it has an air dielectric with one movable plate, or with two fixed plates. Transformer Тр1 should be taken from the TV or the lamp receiver. It should be noted that the high-resistance winding of the same transformer is used as a throttle Др6. If you are thinking how to make a walkie-talkie from the phone, and decided to use low-impedance telephone speakers, you need to include them in the low-resistance winding of this transformer. Also, please note that if you want to use a telephone in the circuit, you can not use it as a radio. But it's worth taking a coal microphone out of it. As a switch "Receiving-Transfer" are good suited to the Galette switches.
The next step is the creation and tuning of the antenna. Consider how to make an antenna for a walkie-talkie. So, after the case of the walkie-talkie is assembled, it will be necessary to make exactly 11 turns of wire for the L1 coil with a thickness of 0.5 mm. In this case, the range setting is set to 27-30 MHz. In the event that an accurate range adjustment is required, it is necessary to use the trim capacitors C1 as well as C2 in the data receiving mode when transmitting the data. In addition, the reception mode of the SA1 switch should be considered. Adjust the range using the factory production control receiver. You can simplify this task by delivering headphones, so the setting will happen much faster.
Having figured out how to do a walkie-talkie, let's move on tothe next step is to make the setting in the transfer mode. You must first set the position of the switches to get a loud hiss in the headphones. It is necessary to obtain a constant stable signal from the used transmitter. It is necessary to pay attention, that thus it is impossible to touch a coil L1. It is necessary to act with the help of the construction capacitor C1. When the carrier signal coincides with the tuning frequency, the super noise should disappear completely. During switching in the radio control receiver, the sound from the microphone should be well heard on the transmission. When the desired results are achieved, it will be necessary to proceed to fixing the structure with special fasteners.
We attach the communication coil and antenna
Using a self-made antenna, it should be in advanceprovide for the power of the antenna, because its further increase can damage the device or simply spoil it. It should be noted that the position of the coupling coil with the antenna must be selected in such a way that the power during the transmission of the signal was maximum, and reception - stable. And as a control transmitter and receiver you can use a tuned pocket radio. The wavemeter circuit for tuning the oscillator circuits of the transmitter and receiver can be seen here:
It should be noted that a number of radio frequency bands on the territory of Russia are reserved for military needs, therefore the work of amateur radio devices in these radio-frequency bands is prohibited.
Also, with time, you can spend someupgrading your radio. For example, it will not be superfluous to install a battery and a charger for it. You can also add cooling radiators for transistors and make an output for connecting an external microphone, headphones and an external antenna. With these additions, no one shop radio can match yours!