SU37608A1 - Radio transmitter - Google Patents

Description

When generating short waves by means of three-electrode lamps, wires that supply current to the anode and to the grid, if such, as is the case in most known circuits, are part of an oscillating circuit, have a large effect on the oscillation frequency, especially at very short waves. . This circumstance should be viewed as a major disadvantage, because either the frequency cannot always be reproduced accurately, or various extraneous interference begins to affect it. The latter circumstance is particularly unpleasant, especially with short waves, since compared to long waves, even a small percentage deviation in the length of the sent wave can cause such strong oscillations in the receiving apparatus that the practical work of the receiver can be considered impossible in advance.

A switching circuit is already known, in which the connecting wires serve exclusively to connect the DC voltage to the anode and the grid and do not participate in passing an alternating current or an alternating voltage; thus, these wires cannot affect the frequency of oscillations generated. However, this scheme assumes

634)

The use of two completely identical generator lamps is known as the push-pull circuit (push-bullets) or the symmetric circuit. The object of the present invention is to achieve the same advantages when using the lamp alone.

In the attached drawing of FIG. Figure 1 shows the existing dual lamp symmetric switch; FIG. 2 diagram corresponding to the invention, and / and 2 (Fig. 1) denote two three-electrode generator lamps, 3-self-induction and 4-capacitance connected between the two anodes of the anode oscillatory circuit. In a similar way: 5 self-induction, 6-capacitance of the grid oscillating circuit connected between both grids, 7 - heat battery, 8 - anode battery and 9 - leakage resistance. Due to the full symmetry, at the midpoints of the coils to which the DC wires are connected, there are nodal points of the AC voltage, so that the connecting wires of the DC current from the batteries to the grid do not pass through the alternating current, and the frequency The oscillations depend solely on the constant coefficients of the oscillatory circuits.

FIG. 2, according to the invention, pr; There is only one lamp. In the drawing they are marked with numbers: 7 - generator tube, 2 self-induction of the anode oscillatory circuit, 3-capacitance of the anode oscillatory circuit, 4-self-induction of the oscillatory circuit, 5 - capacitance of the oscillatory circuit, 5-battery, 7-anode battery. Instead of the second lamp, two equalizing capacitors 8 to 9 are applied here, the capacity of which exactly corresponds to the size of the internal capacities of the lamp grid - anode and cathode grid, so that the circuit shown in FIG. 1 full symmetry is observed and in this case, 70 means leakage resistance.

In most cases, the symmetry remains sufficiently complete if the equalizing capacitor corresponding to the grid – cathode capacitance is absent. The alignment with the help of two capacitors 8 and 9 may seem insufficient at the first glance, since the ohmic resistances of the lamp between the cathode and the grid and between the grid and the anode remain uncompensated. However, this circumstance is of little importance just for short waves, since with a decrease in the wavelength of

the ohmic resistance becomes insignificant compared to the watt-free resistance (in this case, capacitive resistance).

The subject of the patent.

Claims (2)

1. A radio transmitter, in which a DC source is connected to symmetrical points of the grid and anode circuits, characterized in that the grid oscillating circuit 5, 4 is connected to the anode through an equalizing capacitor 8, which capacitance corresponds to a net capacitance and connected in series with the capacitor 5 is the anodic oscillating circuit 2, 5, and on the other hand is connected to the cathode through a second compensating capacitor 9, whose capacitance corresponds to the cathode-grid capacity, and the source is current-stand 7 is attached to a midpoint of the grid katuschki oscillation circuit through a resistance JO (fig. 2). 2. The change of radio transmitter according to claim 1, characterized in that only one compensating capacitor is used, namely the one that corresponds to the grid-anode capacitance. to the patent of a foreign company;, Akts. L 37608 K. Lorenz Island P | 1gschsch. 43H i - . 0 1: 4eig. 2