Car models are successfully used not only for entertainment purposes or for participation in sports competitions. Simulation also allows testing the aerodynamic properties of the future vehicle structure and verifying the operation of vehicle controls. For convenience, the models are equipped with a radio control system, an important part of which is the transmitting device.
Necessary
- - radio components provided by the transmitter circuit;
- - control elements (buttons, levers, switches);
- - fasteners;
- - foil-clad getinax or textolite;
- - duralumin sheet 1 mm thick;
- - soldering iron or soldering station;
- - wave meter;
- - voltmeter;
- - milliammeter.
Instructions
Step 1
Familiarize yourself with the design and circuit of the transmitter used to control the models. It includes the actual transmitter with a built-in modulator, encoder, switch, power supply, remote control. A schematic diagram of the transmitter with an indication of the constituent elements is shown in Figure 1.
Step 2
Build a transmitter with a modulator using a T2 master oscillator, a T4-T5 modulator and a T3 power amplifier in its circuit. Set the frequency of the master oscillator by selecting the capacitor C5.
Step 3
For a power amplifier, use a P609 transistor or a transistor of the same type with similar amplification parameters, turning it on according to a common base circuit. To simplify the adjustment of the signal in the antenna, the L3C8 circuit can be excluded from the collector circuit of the amplifier by providing an extension coil between the capacitor C7 and the antenna.
Step 4
Assemble low-frequency generators T6-T7, T8-T9 according to the multivibrator circuit, connecting the oscillatory circuit in series. To tune the multivibrator, use coil L4 and capacitors C16-C17 for the first generator, and coil L5 with capacitors C18-C19 for the second. Each of the generators is configured for two commands.
Step 5
Use three 3336L batteries as a power source for the transmitter, connecting them in series.
Step 6
Mount the transmitter on the board, making it from PCB or foil-coated getinax. Make the body of the device from a sheet of duralumin about 1 mm thick. Bring out the buttons, command levers, power switch and whip antenna socket to the front of the housing.
Step 7
Adjust the transmitter. Carefully check the quality of the installation, including the soldering points. Measure the current consumption when the power is on; it should not exceed 100 mA. Perform the final tuning of the frequency characteristics of the master oscillator using a wavemeter, having previously connected the antenna.
