Menu English Ukrainian russian Home

Free technical library for hobbyists and professionals Free technical library

Free library / Schemes of radio-electronic and electrical devices

Antenna switch for Yaesu FT-817 transceiver. 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

DGOZB proposed an automatic antenna switcher for the Yaesu FT-817 transceiver. This transceiver can operate on 12 amateur bands from 160m to 70cm with only one antenna connector. To identify the included range, the author used the BAND DATA output of the ACC connector of the transceiver (Fig. 2), on which there is a voltage that varies in steps of 0,33 V depending on the range (Table 1).

Range, m Band Data, V Estimated value, V
160 0,33 0,34
80 0,66 0,69
40 1,00 1,03
30 1,33 1,33
20 1,66 1,68
AM k.A. 2,03
17 2,00 2,3
15 2,33 2,37
12 2,66 2,63
10 3,00 2,97
6 3,33 3,33
VHF-FM k.A. 3,67
2 m 3,66 3,67
70 см 4,0 3,98
k.A. - not in the specification

The switch circuit (Fig. 1) is based on the IC of a multi-channel comparator (or quasi-ADC) A277D (analogous to UAA180), which has 12 outputs (pins 4 ... 15), on which 0 V appears relative to - Up, depending on the voltage at input (vyv.17).

Antenna Switch for Yaesu FT-817 Transceiver
Fig.1 (click to enlarge)

For the correct operation of the switch circuit with the FT-817, first set the lower threshold of the comparator, for this, a 2,2 kΩ potentiometer achieves 0,33 V at pin 16 A277D, then when you turn on 160 m in the FT-817, 15 V will appear at pin 277 A4,2D. The upper limit of the 3 V comparator on pin 277 of the A2,2D is set using a second 2 kΩ potentiometer. Power is supplied to the circuit from the transceiver through the same ACC connector (Fig. XNUMX).

Antenna Switch for Yaesu FT-817 Transceiver

The proposed scheme switches 4 antennas, after a simple refinement, it can switch up to 12 antennas.

Author: Knut Theurich (DGOZB); 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

NASA compact lunar rover 23.12.2020

A new model of a compact lunar rover, created by a private company, has been successfully tested at the NASA Research Center in Florida.

Researchers at the Kennedy Space Center in Florida recently tested a new robotic rover in a 120-ton container of rocks and regolith dust that simulates the surface of the moon. The four-wheeled CubeRover traversed abrasive dust dunes, turned on the spot, then moved up and down steep trench walls and completed over 150 mobility tests.

The test rover has a standardized size, which makes it easier to transport it into space.

The commercial development of small rovers allows engineers, entrepreneurs and scientists to test new, existing and risky concepts first on Earth and then on the Moon. CubeRovers rovers are the first to demonstrate a range of capabilities, such as recharging from a centralized power source in a regolith environment, recovering surface materials, and creating a local communications infrastructure.

The standardized design of the rover creates opportunities for a range of missions, expanding scientific, research and commercial activities on the Moon.

"CubeRovers are lightweight (about 4,5 kg) and have relatively low launch and development costs. This significantly reduces flight costs and makes CubeRovers an ideal platform for technology demonstration missions," said Mike Provenzano, director of planetary mobility at Astrobotic. who created the all-terrain vehicle.

As part of the Artemis program, it is planned to start regular launching of dozens of scientific experiments and technologies on the surface of the Moon next year, and in 2024 to deliver a person to the Earth’s satellite.

Other interesting news:

▪ Flute, which is nine thousand years old

▪ Fuel cells will become cheaper

▪ Compact tokamak warmed up to a record 100 million kelvins

▪ Trap of eternal desires

▪ ICL5102 - Efficient half-bridge AC-DC converter controller with PFC

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 Girl of my dreams. Popular expression

▪ article Where do Siamese twins live, who are connected by brains in the thalamus? Detailed answer

▪ article Riding loop. Travel Tips

▪ article Polyethylene insulation. Encyclopedia of radio electronics and electrical engineering

▪ article Flight into space. Focus Secret

Leave your comment on this article:


Email (optional):

A comment:

All languages ​​of this page

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