The book will help a radio amateur create a transmitting and receiving complex with good characteristics at minimal cost. The material is presented in sufficient detail, with complete electrical data for direct and alternating current, with detailed drawings of printed circuit boards, with a method for setting up the transceiver set-top box, and the features of working with it are explained. Interesting material on improving the characteristics of the receiver to increase its sensitivity and selectivity.
The book contains information on how to use the manufactured set-top box to work with digital communications and connect a PC to the set-top box. The book also presents diagrams and methods for setting up devices useful for radio amateurs, such as a “city radio amateur” antenna that does not interfere with television reception, a matching device for tuning this antenna, and a push-pull power amplifier with high efficiency. The book is intended for a wide range of radio amateurs.
Chapter 1
Theoretical foundations of amateur radio communications
1.1. Types of modulation, their advantages and disadvantages1.1.1. Telegraph signal
1.1.2. Single sideband signal
1.1.3. Frequency modulated signal
1.2. Schemes for building an amateur radio station
1.3. Ham radio antennas
Chapter 2
Receiver with modern parameters
2.1. A secret radio ahead of its time2.2. Modification of R-250 receivers (M, M2)
Chapter 3
Transceiver attachments for the receiver
3.1. Principles of console construction3.1.1. "Retro-N" is an ideal console for a beginning radio enthusiast
3.1.2. Set-top box for beginner radio amateurs “Retro-N”
3.1.3. Set-top box printed circuit boards
3.1.4. Set-top box housing
3.1.5. Details
3.1.6. Setting up the “Retro-N” console
3.2. Set-top box for EXPERIENCED radio amateurs “Retro-M”
3.2.1. Block diagram of the “Retro-M” console
3.2.2. Set-top box printed circuit boards
3.3. Digital scale of the set-top box
Chapter 4
Radio station equipment
4.1. Compact power amplifier with high efficiency.Details
Design
P-loop data
Amplifier parameters
4.2. All-band antenna and matching device for it..
SU details
Device setup procedure
The procedure for setting up the control system when changing the range
4.3. Digital communications
Chapter 5
Multi-mode program for radio amateurs MixW
System requirementsBrief overview of MixW features
Installation of MixW and description of the program window
Connecting a computer and transceiver
Computer serial port pin correspondence (COM port)
Configuring the program and necessary settings in Setup
Working with the program
Transmission work
Working with the program in RTTY mode
Working with the program in CW mode
Features of use in SSB
Using Function Keys and Hot-Keys
"Hot" keyboard combinations (Hot Keys)
MixW Macros
List of macros
Receiver power supply diagram R-250M2
Year: 2004
Publisher: "Science and Technology"
Russian language
Pages: 115
Format: PDF
Size: 15 Mb
You will need
- Transistor P416
- Variable resistor 47 kOhm
- Resistor 10 kOhm
- 2 capacitors 0.022 mF
- Capacitor 0.033 mF
- Capacitor 4700 pF
- Capacitor 100 pF
- 33 pF capacitor
- 51 pF capacitor
- 2 tuning capacitors 4-15 pF
- Throttle (L2) 20-60 µG
- Carbon microphone
- High impedance phones (headphones)
- Telescopic antenna
- 40 cm of copper wire with a cross section of 0.5 mm
- 9-12 V battery
- Switch (SA1) - 2 positions for 2 groups of contacts (double toggle switch possible)
- A piece of getinax or textolite for the mounting panel
- Mounting wire
- Power switch (not shown in diagram)
- Toy radio transmitter
- Tools
- Soldering iron
- Wire cutters
- Pliers
- Tweezers
- Drill
- Drill
Instructions
Assemble the parts according to the diagram. Set coil L1 to the range 27-30 MHz. Its winding data is as follows: 11 turns of a 0.5 mm drive are wound on a blank with a diameter of 10 mm. Accurate adjustment to the range is carried out by trimming capacitors C1 (receive mode) and C2 (mode), taking into account that in the circuit SA1 is in receive mode. Adjustment based on a control receiver (for example, a factory-made children's radio). The easiest way to do this is in transfer mode. Having switched the switch to receive mode, achieve a loud hiss in the headphones by adjusting the transistor mode with a variable resistor.
Without touching coil L1, use tuning capacitor C1 to achieve stable reception of the signal from the control transmitter (the same children's radio intercom). If you are making a walkie-talkie to replace a damaged one, configure it according to the existing one.
The design of the housing can be anything, it depends on the dimensions of the parts. If the housing is metal, then the antenna must be protected from contact with the housing by a reliable insulator. Plexiglas can be used as an insulator.
note
Part numbers are indicated on the diagram
It is advisable to collect 2 similar radios at once.
Sometimes, for reliable operation of a radio station, it is necessary to select a transistor by replacing it.
Helpful advice
Instead of a telescopic antenna, you can use a piece of rigid copper wire or copper tubing. The length of the wire or tube is 0.5 m.
The radio is mounted on a board made of dielectric material. It can be either printed or mounted. It is possible to use volumetric installation.
The radio is configured with the antenna connected and fully extended. During setup and operation of the radio, do not touch the antenna with your hands.
The circuit uses a high-frequency p-n-p transistor, but it can be replaced with any other low-power high-frequency transistor, including n-p-n structures, for example KT315. In this case, it is necessary to reverse the polarity of the power supply.
When hunting, fishing, hiking, at work, as a baby monitor or just to communicate with friends... And this is not the whole list where a walkie-talkie will come in handy. It is worth saying that it is not difficult to make, but you still need to have some knowledge in the field of physics and radio electronics.
Naturally, radio components are needed for operation:- Transistors (MP 42 - 4 pieces and P416B - 3 pieces);
- Resistors (3K, 160K, 4.7K - 2 pieces each; 22K, 36K, 100K, 120K, 270K - one piece each; 6.8K - 6 pieces);
- Capacitors (10 MK 10V, 3300, 1000, 100, 6, 5-20, 22, 10 - 2 pieces each; 5 MK 10V - 4; 0,0,47 MK - one);
- Telescopic antenna;
- Speaker;
- Microphone;
- Switch, switch;
- 2 textolite boards;
- Wires and wire;
- And of course, a power supply, a soldering iron, desire and a little patience.
The next step is to wind the coils onto the frame. There are about 200 turns in one winding. 
Are you tired of paying for mobile communications all the time? Do you want to upgrade to a free plan? Or do you want to have constant, free communication with your boys in the area? Then this walkie-talkie circuit, which you can assemble with your own hands, is for you.
To make one radio you need:
- Transistors: P416B (3 pcs) and MP42 (4 pcs);
- Resistors: 3K (2 pieces), 160K (2 pieces), 4.7K (2 pieces), 22K, 36K, 100K, 120K, 270K, 6.8K (6 pieces);
- Capacitors: 10MK*10V (2pcs), 3300MK (2pcs), 1000MK (2pcs), 100MK (2pcs), 6MK (2pcs), 5-20MK (2pcs), 22MK, 10MK, 0.047MK, 5MK*10V (4pcs);
- Antenna;
- Microphone, speaker;
- Switch, switch;
- DC source;
- Textolite boards (2 pcs);
- Wires;
- Wire with a diameter of 0.1 mm. and 0.5 mm.
Scheme of a simple homemade walkie-talkie:
How to make a walkie-talkie with your own hands
The common antenna for receiving and sending the signal is A1.
Power switch – SA1.
The switch connecting the homemade radio station to the current source while sending the signal to the transmitter and receiver upon receipt is SA2.
Number of turns:
Coils L1 and L5 – 10 turns.
Coil L2 has 4 turns and is located between the halves of the winding of coil L3, which contains 8 turns and has a wire tap in the middle.
Coils L4 and L6 – 200 turns, 0.1 mm wire around the MLE-0.5 resistor with min. resistance 1Mohm.
Well, the coils for the radio are ready.
If you still have the desire to make DIY walkie-talkies, then you probably understand at least something in electronics, and that means it won’t be difficult for you to place the parts on two boards (one of which has a master oscillator, and the other with a receiver and a low-frequency amplifier) on one side and connect them with an insulated wire ( diameter 0.2-0.3mm) on the other. Then connect using a stranded wire insulated with vinyl chloride to the battery.
Printed wiring can be done if you have foil getinaks, and for the frame of a homemade walkie-talkie, centimeter-sized pieces of wire driven into holes with a diameter of 1 mm are suitable.
The windings of the coils and chokes should be mutually perpendicular, and the C15 handle should be on the front panel of the radio. The generator must be separated from other parts by a tin screen.
Configuring and debugging the radio
Debugging begins with improving the reception quality; to do this, you need to replace R10 with a variable one with a resistance of 33-47 kOhm and wait for the maximum noise volume. Next, using a tuning core, we change the inductance L5, achieving the highest quality signal. After this, we return the previous resistor.
Modern element base makes it possible to create radio-electronic devices with excellent technical characteristics, minimal dimensions and low power consumption.
Of course, for radio amateurs living far from large cities and regional centers, the possibility of purchasing foreign integrated circuits is practically unrealistic, even though they are relatively inexpensive. However, this does not mean that the design of devices using modern ICs should be stopped.
Radio amateurs are offered the option of a portable radio station, very similar to the “Hummingbird” radio station. Compared to the “Hummingbird”, the described design has a higher output power, better sensitivity of the noise suppression system (NSS), and also uses a slightly different connection of the IC and transmitter transistors.
Specifications
- receiver sensitivity, no worse, µV...................0.5;
- transmitter output power, W...................................3;
- deviation, kHz................................................... ...............3;
- type of modulation................................................ ............ World Cup;
- communication range in open areas, km...................................6;
- communication range in city conditions, km...................................2.
It should, however, be noted that the characteristics of the radio station depend on many factors, therefore, when repeating the design, deviations of the values up or down from those indicated above are possible.
Schematic diagram
In Fig. Figure 1 shows a schematic electrical diagram of the radio station. In transmission mode, the signal from the VM1 microphone is supplied to the cascades of the DA1 MC2833R transmitter microcircuit. IC DA1 performs the functions of amplifying the low-frequency signal, limiting it, generating a high-frequency signal and modulating it.
The microcircuit also includes two transistors capable of operating at frequencies up to 200 MHz (according to the datasheet - up to 500 MHz). The signal from the RF amplifier (pin 14 DA1) is supplied to the base of the first transistor (pin 13) through the resonant circuit L2, NW, on which the main signal of the transmitter is isolated (or a harmonic if a quartz resonator is used at a minor frequency).
In the collector circuit (pin 11) a resonant circuit L3, C8 is installed, tuned to the transmission frequency. From the coupling coil L4 through the separating capacitor C10, the modulated signal of the operating frequency is supplied to a line of amplification stages on transistors VT1., VT2 and then through a double P-circuit to the antenna WA1.
Rice. 1. Schematic diagram of a homemade radio station at 27 MHz, 3 Watt capacity.
In reception mode, the signal from antenna WA1 through capacitor C27 is supplied to communication coil L12. Now the second transistor of the DA1 chip performs the function of a resonant UHF receiver. Using a bipolar transistor as a UHF, of course, cannot be considered the optimal solution. It would be better to use a field-effect transistor (for example, KP307, KP350).
However, when developing the radio station, the goal was to create a design with the least number of parts, overall dimensions and cost. For those who like experimenting, we can recommend using the second transistor IC MC2833 as part of the transmitting path, and using a field-effect transistor as a UHF receiver.
Next, the received signal is fed to the DA3 multifunctional chip, where the high-frequency signal with frequency modulation is completely converted into a low-frequency information signal. This IC contains an adjustable noise suppression system. From output DA3 (pin 9), through the volume control resistor R15, the low-frequency signal is supplied to the ULF, made on the DA2 MC34119R IC.
Switch SA2 turns off the standby mode in cases where the signal from the received radio station is at a very low level. Transistors VTZ and VT4 are used as an SNR amplifier.
When a received signal appears, the noise level decreases significantly and the transistors put the DA3 chip into working condition. The rest of the time, this IC is in the “off” state. This allows you to significantly reduce energy consumption during duty reception.
The microcircuits are powered using integrated stabilizers DA4, DA5 78L06, so the functionality of the radio station is maintained when the supply voltage is reduced to 6...7 V. Instead of the indicated ICs, stabilizers of the 78L05 type can also be used, but in this case the output transistors of the transmitter will operate with low efficiency , not providing communication over the proper distance.
One of the disadvantages of this design can be considered the need to select receiver and transmitter crystals with an IF difference (usually 465 kHz, but 455 kHz is also possible). However, this gives a gain in the size of the device as a whole and improves frequency stability.
Even a beginner can set up a radio station. However, the radio station should be assembled in stages. That is, they install the elements of those cascades that will be configured at the current time. This will avoid many problems in setting up the entire device. First, the operation of the receiver is checked, and then the transmitter.
Assembly and configuration procedure
1. Receiver:
- a) ULF chip DA2 and corresponding attachments up to resistor R15 of the volume control;
- b) DA3 receiver chip and corresponding attachments up to UHF; in this case, the SPS should be turned off by closing contacts SA2;
- c) setting up the IF circuit L15, C42.
2. Transmitter:
- a) transmitter chip DA1 and corresponding attachments to transistor VT1;
- b) setting up the L2, SZ and L3, C8 circuits into resonance (at this stage you can separate the receiver and transmitter at a distance of 3...5 m and adjust the IF circuit);
- c) line of transmitter transistors VT1 and VT2 and P-circuit elements (L7, L8, C16...C18).
It should be remembered that the transmitter power amplifier must be configured with an antenna or its equivalent connected! First we set up the L5, C11 circuit, and then the P-circuit. As a result, we adjust all the transmitter circuits (if necessary) until the maximum performance of the device used is achieved and we tune the UHF receiver circuits L11, C26 and L14, C28 into resonance. Now you can adjust the SNR using variable resistor R23 based on the received signal from the transmitter.
In both modes (reception and transmission), it will be necessary to tune the RF circuits to resonance. By changing the inductance of coil L1, it is necessary to set the operating frequency (according to the receiver). Resistor R9 regulates the gain of the microphone amplifier. The greater the resistance of R9, the greater the gain. In the receive mode, you should adjust the IF circuit according to the received signal (or pre-adjust it to the maximum noise level with the PN system turned off; and finally, according to the received signal). The UHF input circuits are then adjusted.
Finally, the P-circuit is adjusted to the maximum current in the antenna in transmit mode. It is better to make adjustments using a non-resonant wave meter based on the maximum deflection of the instrument needle. The antenna can be used either telescopic or spiral. It all depends on the “taste” of the designer. You should definitely remember that without an antenna or if its connection is poor, you can damage the output transistor of the transmitter power amplifier, so its installation must be taken with full responsibility.
The SPS switch SA2 should be connected not between the base of the VTZ transistor and the common wire, but between the VTZ base and the right (according to the diagram) output of the DA5 stabilizer through a resistor with a resistance of 68 kOhm.
When contacts SA2 are closed, the operating point of the transistor VTZ shifts, which turns off the system and allows you to listen to weak signals under poor reception conditions.
To adjust the SSH response threshold, it is necessary to temporarily install a variable resistor with a resistance of 27 kOhm instead of resistor R22. The resistor R23 slider is placed in the middle position and, by rotating the temporary resistor slider, a position is found in which the SNR switches in the absence of a transmitter signal. Then, having measured the resistance of the temporary resistor, a permanent resistor is soldered in its place.
Details and finalization of the scheme
The transmitter power amplifier has been improved. To do this, the values of resistors R5 and R7 were changed to 1 kOhm each, and resistors R* 33 kOhm and R** 47 kOhm were added (Fig. 2). Since in this case the operation of the power amplifier stages occurs in class A, the quiescent current of the transistors increases. However, in this case there is a noticeable increase in the gain and, accordingly, the signal sent to the antenna, which in turn increases the communication range.
Rice. 2. Refinement of the transmitter power amplifier, circuit.
The winding data of the inductors are given in table. 1.
Chokes L6, L9, L10 are standard type D-0.1 with an inductance of 110 μH. The coil of the IF circuit is wound on an SB-12 core. The adjustment is made by rotating the core. Frameless coils L7, L8 P-circuit are adjusted by stretching or compressing the turns.
If you couldn’t find the MC34119R chip, don’t despair. The silent setting function can be performed on another widely used LM386 microcircuit that does not have an “ON/OFF” input, or simply on transistors according to any known circuit. An example of using the LM386 IC as a ULF receiver is shown in Fig. 3. In this case, transistor VT4 and resistor R20 are not installed, and points A, B and C, shown in Fig. 1 are connected to each other accordingly.
Rice. 3. An example of using the LM386 IC as a ULF receiver.
Table 1. Winding data of inductors
| Coil | Frame diameter, mm | Core | Number of turns | Wire diameter, mm |
| L1 | 5 | from SB-12 (trimmer) | 15 | 0,3 |
| L2, L3, L5, L11, L14 | 5 | from SB-12 (trimmer) | 7 | 0,5 |
| L4 | over L3 | - | 3,75 | 0,5 |
| L12 | over L11 | - | 3,75 | 0,5 |
| L13 | over L14 | - | 3,75 | 0,5 |
| L7, L8 | 5,5 | - | 8 | 0,8 |
| L6, L9, L10 | - | standard throttle D-0.1 | - | - |
| L15 | 4 | SB-12 (assembled) | 80 | 0,1 |
Printed circuit board
Printed circuit board drawings are displayed in mirror form (Fig. 4 and Fig. 5 - especially for the “printer” manufacturing method. Dimensions of printed circuit boards: transmitter and UHF receiver board 60x67.5 mm; receiver - 57.5x35 mm. Quality of printed circuit boards at using the method below turns out pretty good.
1.In a graphic or text editor, select the required size of the printed circuit board design. We print it with maximum toner consumption on a laser printer on paper from any poster. Printing must be on the reverse (white) side. The paper should have a glossy sheen. You should not print on plain paper. Do not touch the finished drawing with your hands - greasy stains will remain and the toner will not stick to the foil.
2.Cut out the printed design with a 2cm border. We place the resulting workpiece on foil fiberglass treated with fine sandpaper, cut 7...10 mm larger than necessary on all sides (do not touch it with your hands, otherwise the toner will not stick to the foil!), so that the toner is attached to the foil, and wrap the paper.
Rice. 4. Transmitter circuit board.
Rice. 5. Receiver circuit board.
Place it all on a hard surface and iron it for 1 minute. The time can be selected experimentally. Then let the fiberglass laminate cool a little and lower it into very warm, but not hot water. After 20 minutes, carefully roll the paper into lumps until there is no paper left on the foil. If the paper remains in some places, do not worry - the acid (or other etching solution) will do its job.
3.Dip the board into the etching solution. We're poisoning. We rinse. Cut to required sizes.
If the above points are carefully followed, accuracy will depend on the preparation of the fiberglass surface. Otherwise, the paper will peel off along with the toner.
