Electronic kaleidoscope

Electronic Kaleidoscope - Arranging recovered electronic parts

Reading time: 2 minute

Author: George D. Oprescu
Publisher: Albatros - Bucharest
Collection: Crystal
Year of publication: 1987

What it is?

The book presents assemblies with integrated circuits, transistors and electronic tubes.

Electronica provides people with various devices and installations necessary to achieve the dreams of the most daring. Communicating news and impressions, printing sound and playing high fidelity music, television, ensuring the safety of maritime, road and air navigation, fighting the disease, electronic computers, automation and much more make up the natural setting of today's life.

As a technical field of easy development, electronics has undergone changes in the last decades, from which many other fields have benefited. Medicine, nuclear physics, modern optics, scientific research in general are long intertwined use of various electronic processes scientific investigation and the use of these techniques is intensifying day by day.

Whatever profession you choose, electronics present everywhere will provide even more support in the future. So, together with the professional doctor, or metallurgist or architect, will remain in the same person, confident, optimistic and amateur of electronics, lover of simple or complicated assemblies, achievements that must have a single basic quality, that of operating at the parameters ask, to work for a long time without defects, to have the lowest possible cost, an attractive aspect, to optimally solve a problem.

In this race towards the future, towards better and better equipment, cheap and safe, technique lovers, amateurs, carry on the enthusiastic work of their ancestors, become passionate researchers, who intertwine their daily work, with moments of great satisfaction, when the simpler or more complicated equipment works, exceeding expectations.

Regardless of age, child, adolescent, adult or elderly, the amateur always remains a young researcher, always ready to follow any new turn of the electronic technique he loves and which brings him new satisfactions every day.

Continued use of the baggage of theoretical and practical knowledge in the field of electronics, along with the chosen basic job, will create the happy man, able to use the latest techniques for the well-being and happiness of those around him, optimizing life.

Electronics is primarily a matter of fine mechanics, clean, reliable. Execution of electronic assemblies in amateur mode educates patience, perseverance, increases dexterity and intelligence.

The structure of the book

  • Miniature radio receiver
  • Portable radio receivers with transistors
  • Portable radio receiver with 3 transistors
  • TEC radio receivers
  • Shortwave adapter
  • Radio receiver for tested transistors
  • Ultra-shortwave radio receiver
  • Radio receiver for amateur radio bands
  • Radio receiver for superheterodyne reflex
  • Heterodyne radio receiver
  • Radio receiver with two electronic tubes
  • MA-MF radio receiver
  • Replacing a frequency change tube
  • Replacing an amplifier tube for FI
  • Aperiodic antenna amplifier for television
  • Amplifier for television antenna
  • Auxiliary audio amplifier
  • Cassette amplifier
  • Cassette player playback amplifier
  • Mini amplifier
  • Magnetic dose preamplifier
  • Picup dose corrector
  • Pickup Amplifier (I)
  • Pickup Amplifier (II)
  • Audio montages with TEC
  • Installations with operational amplifiers
  • Audio montages with CMOS integrated circuits
  • Tape recorder amplifier with electronic tubes
  • Noise reducers
  • Passive audio frequency filters
  • Active voice filters
  • Stereodine
  • Single-speaker stereo
  • Reverberator
  • Reverberator with electronic tubes
  • Simple variant of reverberator
  • Video noise reducer
  • Presence sensor
  • Time relay for photography
  • Luminaire mounting
  • Flashing lights
  • Miniature transformers
  • Network transformer
  • Universal power supply
  • Measuring instrument on the power supply panel
  • Miniature power supply
  • Coil block
  • Electric speed stabilizer
  • Zener mounting adjustable
  • Bridge for measuring parts
  • Transistor tester with optical indicator
  • The ohmmeter as a transistor tester
  • Noise generator
  • Rectangular audio frequency generator
  • Audio frequency generator
  • Tracer and signal injector
  • Band microphone
  • Recovered speakers
  • Building a pickup
  • Construction of tape recorder heads
  • Polishing a magnetic head
  • Construction of miniature relays
  • Arranging recovered electronic parts
  • Useful tools from steel scrap
  • Letcon miniature
  • Diode replacements
  • Reuse of defective transistors
  • Plate for experimental installations
  • Simplification of printed wiring
  • Mounting module
  • Spider-type mounting
  • Battery regeneration
  • Expression in decibels
  • A useful table - Ohm's law
  • Color code
  • Some guidelines for using audio tapes and cassettes
  • Author's advice for beginners


  1. God, what a book! I made many installations according to the diagrams presented: a super-reaction receiver, audio station, light organ, antenna amplifiers, etc.

  2. Of course! The great professionally designed scheme, scientifically even, made with Chinese pieces entirely, with astronomical tolerances, I mean assets not liabilities. You plug it in and you don't know how it works, smoke comes out or not, it booms or not ... it's a matter of time!

  3. You are right, but let us remember the late Mr. G. OPRESCU, who in his books encourages us to make assemblies with fairly high tolerances for parts and the assemblies worked flawlessly.

  4. All the respect for our forerunner in electronics, a progressive but modern spirit, an apostle in my childhood of ... cherry electronics.

  5. What times! There was also Tehnium, Almanah Tehnium and the magazine for pioneers, brochures translated from Russian ... a whole literature at the beginning of the road! And especially the fascinating electronic tubes! Who did not even build an amplifier with ECL82 and a magic eye or did not wind a transformer and other jewelry did not make electronics!

  6. I've had it since it appeared. I lost it. I found another in very good condition. The beginnings of the passion with her began.

  7. I built two TVs inspired by his book "Build a TV", with scattered parts from various sources and they worked. That's how I learned TV and then I did troubleshooting to make pocket money in my high school years.

  8. And if it's still time to brag after 46 years, at 17 I was building my 3rd tape recorder with all the mechanics, on tubes. I only have the handmade wiring with my name and the date I built it, I was 17 years old. Unfortunately, I didn't take any pictures, I only remember them. Today I turned to fine mechanics, I work on a miniature milling cutter that is almost ready and I have tens of kilograms of parts waiting their turn. I want to give up mechanics and go back to electronics. The point is that one without the other is not possible, you need mechanics in one. I also have a milling cutter made by me in 2008 with a digital display on 3 axes with which I drill holes in coordinates and mill.

  9. Beautiful story. But still I think that to conceive something in this field you need electronics but also fine mechanics.

  10. You definitely run into mechanical problems that you can't get rid of. Construction of a transformer housing, a wiring cut in a more complicated shape with holes say rectangular, spacers on precise and non-standard size, holes in line with very precise distance between them, with dimension to tenths of a millimeter, buttons, holes for measuring devices , sockets and other parts, boxes and much more, including winding, insulators, etc.

    1. For the same reason that there are no more technical-application circles: it is not wanted. The sphere of politics (regardless of color) has no interest in raising new generations, to whom both the mind and the hand should go. All they need is "vegetables" to scratch their stomachs and vote as they are manipulated on "social" networks.
      In other countries there are as many magazines and e-books as there were decades ago. Demand exists in our country, the young generation cannot be blamed. If you open their taste to Electronics, they will buy books and magazines like hot cakes, as we did in our youth.
      In Germany, every electronics student receives a digital multimeter, an analog multimeter and an oscilloscope. And they are his. The theory is thorough, from foundation to present, and is combined with practice. A graduate of ours is full of old and purely theoretical things, and as a practice I sincerely doubt that from the scheme of a "firefly" with two LEDs he can draw with his hand the wiring diagram, without the help of a dedicated software.

  11. I have it, in physical format.
    Very good, I did some editing there.
    An incident from the time this book appeared:
    I had left school during a long break with another colleague who was also passionate about Electronics, to see what other books they brought. My colleague bought it on the spot, I borrowed a few lei from him, because I didn't have enough money for the sandwich. An old woman witnessed the dialogue between us and said: "Hey, young man, you're going to be a big man if you put your last money for food on the books!"
    I regretted all my life that I had never met him so I could tell him he was wrong…

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