Menu English Ukrainian russian Home

Free technical library for hobbyists and professionals Free technical library

Free library / Schemes of radio-electronic and electrical devices

A simple, pocket, radio station for the village. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Civil radio communications

Comments on the article Comments on the article

As a rule, all schemes of portable radio stations published on the pages of "RL" are designed for a city dweller, for his ability to get scarce elements, rare microcircuits. And for us, the villagers, it is very difficult to repeat a different design. Meanwhile, personal radio communication is relevant precisely in villages and villages, where even now one telephone set is sometimes installed for the entire district.

I myself am a rural resident, and therefore, when developing this design, I tried to take into account our problems with the availability of the element base.

The radio station consists of two parts: a transmitter and a receiver. The transmitter is assembled on a 1,5 mm thick fiberglass board measuring 100 mm x 45 m. The receiver is 60 x 45 mm. Why are there two fees? The fact is that these are two independent designs that can be improved independently of each other. There is one more detail. This design very easily turns into a radiotelephone, since the receiver and transmitter can work simultaneously if they are detuned relative to each other.

The transmitter circuit and coil data are shown in Fig. 1.

Simple, pocket, for the village radio station
(click to enlarge)

The transmitter is assembled on five transistors. Two transistors - in the modulator. Three - in the transmitting part. Transistors are not critical in selection. Any silicon can be used in the modulator: KT315, KT503, KT306, i.e. usually those that can be soldered from old receivers, tape recorders.

The master oscillator also has a wide selection of transistors. KT315, KT306, KT316, KT368 work well here. Quartz - at 27 MHz. In the second stage, KT603, KT604, KT605 work well.

In the power amplifier, you can use transistors such as KT610, KT606, KT907, KT922.

All transmitter coils are wound on IF circuits from industrial radio stations or radio receivers. Coils - with screens and cores. They are very easy to set up, you just need to have a simple wavemeter.

The setting begins with the master oscillator - according to the maximum deviation of the wavemeter needle. The second and third stages are set up in the same way.

The transmitter works confidently on a 7D-0.125D battery, which is also important for a rural radio amateur.

The modulator uses a DEMSh-1 capsule instead of a microphone.

The receiver has always been a difficult device for a rural radio amateur, because, as a rule, it is a superheterodyne. And to set it up, you need devices and microcircuits, which are not available in the countryside, and the nearest city is 180-200 km away. Therefore, my opinion: the best way out is a super-regenerative receiver. For all its simplicity, it has a rather high sensitivity: up to 5 μV, which is not inferior to the "super". The use of UHF not only increased the gain of the receiver as a whole, but also solved the problem with spurious radiation. The receiver circuit is shown in Fig.2.

Simple, pocket, for the village radio station
(click to enlarge)

The K174UN4V microcircuit was used as an amplifier, which is sufficient for loud-speaking radio communication. Its setting is available even to a beginner.

Any RF transistor, both silicon and germanium, can work in the first stage of the receiver. for example, KT306, KT368, KT316, KT315.

The second stage is the regenerator. There are problems here. In these stages, only germanium transistors usually behave well, so GT311 Zh, A, C, B work here. The use of silicon transistors gives unstable results.

A properly assembled receiver begins to act immediately, and the indicator of its operation is noise.

They tune it to the transmitter from their own design for the disappearance of noise. The final tuning is carried out already at the maximum distance of the two radio stations from each other.

The antenna used is spiral, the design of which was given in "RL" No. 5/92, p. fourteen.

I have collected two radio stations that have been serving faithfully for three years. Confident range - 2,5 km - 3 km.

When working in stationary conditions and powered by 12 volts, as well as when using an external whip antenna, the range reaches 10 km.

I do not give printed wiring, because due to the wide range of parts of this radio station, the dimensions of the boards can be arbitrary.

Author: F. Zhupanov, Moldova, town. Taraclia; Publication: N. Bolshakov,

See other articles Section Civil radio communications.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Artificial leather for touch emulation 15.04.2024

In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>

Petgugu Global cat litter 15.04.2024

Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>

The attractiveness of caring men 14.04.2024

The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>

Random news from the Archive

S2-LP - 433/868 MHz narrowband transceiver 11.03.2017

S2-LP is a new 433/868 MHz transceiver from STMicroelectronics, designed to create cost-sensitive IoT devices, but at the same time with high requirements for radio communication quality and consumption.

To what extent this was done can be assessed by looking at the impressive technical characteristics of the new microcircuit. The receiver sensitivity starts from -130 dBm, while the developer can work with a path bandwidth from one kilohertz. The output power is adjustable over a wide range - from -30 dBm to +16 dBm in 1 dBm steps. Thanks to the new class E amplifier, the current consumption at 10mW output power is only 10mA, while in receive mode the consumption is within 7mA. The microcircuit is the best in its class in terms of consumption in transmit mode.

Reducing the current draw of internal RF components often leads to reduced RF performance. However, the S2-LP transceiver performs well both in terms of link budget (> 140 dB RF link budget) and selectivity. Adjacent channel selectivity is 68 dB (@+-12.5 kHz), blocking is better than 80 dB at 2 MHz offset (@433 MHz)

The S2-LP transceiver can work with any external microcontroller. Control is performed in the most familiar way - via SPI with interrupts through customizable GPIO0 ... GPIO3 lines. To work with STM32 microcontrollers, there is a library and a set of examples for STM32Cube.

Features of the S2-LP transceiver:

Narrowband transceiver 430 - 470 / 860-940 MHz
Output power up to +-16 dBm; Sensitivity up to -130 dBm
Air data rate 0.3 - 500 kbps
Modulation types 2-FSK, 2-GFSK, 4-FSK, 4-GFSK, OOK, and ASK
Low consumption in active mode:
6,7mA RX
10mA TX @ +10dBm
Sleep Consumption 600nA (with timer)
Fast wakeup and fast synth setup time
Automatic retries and confirmations
Suitable for Wireless M-Bus systems; 802.15.4g
Case 4x4 mm QFN
Operating temperature -40...+85 °C

Other interesting news:

▪ Walking as a cure for depression

▪ Gravitational lamps work without the mains

▪ Diamond magnetic field sensor

▪ Silicon formats proteins

▪ Frameless smartphone with built-in solar battery

News feed of science and technology, new electronics


Interesting materials of the Free Technical Library:

▪ section of the site Children's scientific laboratory. Article selection

▪ article According to the first number, pour (prescribe). Popular expression

▪ article How did poetry originate? Detailed answer

▪ article Alpine strawberry. Legends, cultivation, methods of application

▪ article Pulse metal detectors PI (Pulse Induction), theory. Encyclopedia of radio electronics and electrical engineering

▪ article Five rings on laces. Focus Secret

Leave your comment on this article:


Email (optional):

A comment:

Comments on the article:

a guest
And in the L4 coil, how to count the taps - from left to right or from right to left?

All languages ​​of this page

Home page | Library | Articles | Website map | Site Reviews