VFO transistors. Scheme, description

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Schemes of radio-electronic and electrical devices

VFO transistors. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Knots of amateur radio equipment. Generators, heterodynes

Comments on the article

The radio amateur D37AW has developed a highly stable 5-5,5 MHz transistor VFO (see figure), which he uses in a transceiver of his own design.

(click to enlarge)

Careful thermal compensation of the circuit made it possible to reduce the generator frequency drift to 200 Hz in the temperature range from +10°C to +50°C.

The VFO is made up of two transistors, while the second transistor (T2) serves as a buffer stage. The load of the buffer stage is a low-pass filter with a cutoff frequency of 6 MHz.

The scheme provides for changing the generator frequency when changing the sideband in SSB mode, which allows you not to adjust the transceiver when switching from VSB to LSB and vice versa. The frequency shift is carried out using a diode switch made on diode D1 and connecting capacitor C9 in parallel with capacitors C10 and C12 in VSB mode.

To increase the stability of the VFO, the circuit is mounted on a chassis made of 3 mm thick aluminum sheet.

Capacitor C2 has a positive TKE, C3-C5 and C7-C12 are zero. Coil L1 is wound on a ceramic frame, L2-L6 - on frames with ferrite cores.

Diode D1 can be used as D104. T1, T2 - transistors KT315A-B.

Literature

"DL-QTC", 1969, No. 1

Publication: N. Bolshakov, rf.atnn.ru

See other articles Section Knots of amateur radio equipment. Generators, heterodynes.

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

Do athletes need warm-ups? 09.12.2002

All sports doctors and coaches unanimously say that before starting physical education, you should warm up well so as not to overwork, stretch or tear your muscles. But Australian scientists from the University of Sydney do not believe there is any strong scientific evidence for the benefits of warming up.

They found, for example, that warm-up forward bends do not prevent muscle soreness after competition or reduce the risk of injury, although why this happens is not yet clear. Asking 77 volunteers to perform simple calisthenics exercises with or without pre-warm-up, the researchers found that the warm-up does not bring tangible benefits and does not contribute to the prevention of muscle pain.

Perhaps the picture will look different if you examine professional athletes who are used to warming up before each workout. As is known, the mechanical properties of human and animal muscle tissues are very complex.

Other interesting news:

▪ Intel Alder Lake-HX mobile processors

▪ Drinking alcohol makes you feel hungry

▪ Dead Sea Manuscripts

▪ Table microphone Yamaha Adecia RM-TT

▪ PrivatBank neutralized a group of skimmers

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Amateur Radio Technologies. Selection of articles

▪ article Bee operating room. Tips for the home master

▪ article What is a dream? Detailed answer

▪ article Coastal boatswain. Job description

▪ article Quad-channel home theater amplifier with LG player remote control. Encyclopedia of radio electronics and electrical engineering

▪ article Charger for sealed lead (gel) batteries. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

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