Radio dla Techników i Amatorów (Radio for Technicians and Amateurs) 1946/03

RADIO dla Techników i Amatorów, Rok I, Marzec 1946r., Nr 1.
(RADIO for Technicians and Amateurs, Year I, March 1946, Number 1)

• From the editorial office (1)
    The new era of nuclear energy that is unfolding before us must now put its tasks on the agenda: Technical culture should become the property not only of individuals, but also of broad strata of our society. Acquiring certain habits, methods and technical knowledge is also a basic condition for creating a sufficiently wide team of people who can actively cooperate in the reconstruction and construction of radio and television in a democratic Poland.
    The tasks facing our radio technicians are enormous, not only because of the necessity to reconstruct what was, but also to create what has not been there so far, i.e. the universality of radio.
    These were the reasons that led us to the issue of the new monthly magazine for technicians and radio amateurs - "RADIO"
• Review of issues in the construction of receivers (2)
     The transmitter and receiver are important elements of radio signal transmission. Technical improvements are made to the transmitting and receiving devices in order to reach the limits of practically achievable possibilities. On the receiving side it is necessary to adapt to the conditions created by the transmitting side and to the conditions of the propagation environment.
     The conditions on the transmitting side depend primarily on the lack of available wavelengths. In amplitude modulation using both sides of the spectrum to avoid mutual interference, the power of the transmitters and the wavelength spacing are reduced more than otherwise desirable.
  • Influence of progress in the construction of electron tubes.
      The progress in the construction of electron tubes in the last 10 years has been taking leaps and bounds through many implementation stages, differing not only in terms of electrical parameters, but also in terms of external performance, connections to the pedestal and construction of the pedestal. In this way, almost every year, a large number of tubes of various types had to be withdrawn from circulation. The newly constructed vacuum tubes were immediately applied to new types of radio receivers, and rarely any type of radio receiver was manufactured for more than one year.
• Frequency modulation (6)
     In recent years, frequency modulation has gained a lot of importance and has found numerous applications. Suffice it to say that currently in America, radio listeners are called to buy radio receivers that enable reception of radio waves modulated in this way, because a number of radio stations will soon use frequency modulation.
• New English radio on three electron tubes (10)
    A new radio receiver from one of the companies in Cambridge has appeared on the English market. Its description is given in "Wireless World". We believe that our readers will be interested in the description of this radio receiver, if only because of the desire to find out what types of radio receivers will have a chance of success in the post-war period.
  
  • Schematic diagram of the radio receiver.
  • 
      New English radio receiver on electron tubes (schematic diagram).
  • Some design details.
      The base of the structure can be very easily removed from the box. The loudspeaker is easy to disconnect as it is connected via plugs. The knobs on the front of the radio receiver are designed in such a way that they can be pressed in.
• Low Frequency Resistance - Capacitive Generator (12)
      The principle of operation of generally used, measuring low-frequency generators is to generate two high-frequency vibrations, then fed to a non-linear system, e.g. a detector tube. Since the frequencies f1 and f2 of these vibrations are very close, a low-frequency oscillation is produced, being the difference f1-f2.
  
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• Capacitor as a reduction resistance in the heating circuit of universal radio receivers (15)
     Replacing a burnt or damaged resistor lamp in the glow circuit of a universal radio receiver is now very difficult due to the lack of proper parts.
     If the radio receiver is powered from the alternating current network, the corresponding reducing resistor can be successfully replaced by a capacitor. Conventional paper (block) capacitors are suitable for this purpose.
• Signal - generator (Modulated oscillator) (16)
• Magnetic Voltage Stabilizers (22)
    Almost all measuring instruments and precise operating devices based on vacuum tubes are mains powered. Most of these devices, such as voltmeters based on electron tubes, measuring amplifiers, and current measuring devices, have calibrated scales and require the constant voltage supplying the anode, glow and grid circuits.
• Review of diagrams of radio receivers produced in the years 1940 - 1944 (24)
     There are currently radio receivers of various origins in our area. Often, when repairing these radios, we are forced to recreate schematic diagrams, which takes a long time and cannot always be accurately performed. Willing to come to the aid of a large group of radio technicians, we will place schematic diagrams of various radio receivers, giving the opportunity to observe changes and novelties in radio systems.
  • 
      Radio receiver: Telefunken type 913 WK.
  • 
       Radio receiver: Telefunken type 965 G.W.
  • 
       Radio receiver: Körting Nobilis 40 WK.
  • 
       Radio receiver: Saba 357 WK.
• Tubes tables for receivers and amplifiers (29)
    The variety of types of tubes available on our market prompted us to develop tables covering all types of tubes found today.
• Nomogram Number 1 - Calculation of Network Transformers (31)
    For low-power transformers (up to 1kW) intended for powering radio receivers and radio amplifiers, we can calculate all data with sufficient accuracy using the nomogram below.

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