SU30322A1 - Modulating device - Google Patents

Description

The invention relates to i devices for modulating oscillations by changing the setting, especially when radiotelephony using high frequency machines. Its essence lies in the fact that for modulation two or more circuits are used, tuned and modulated so as to eliminate phase changes, due to a change in the construction of circuits, for which each of the two connected circuits is included in this way. that under the action of the telephone current, the period of natural oscillations of the primary circuit is lengthened, and the period of natural oscillations of the secondary circuit is shortened by an equal amount.

In FIG. 1-5 depict diagrams explaining the physical meaning of the phenomena that substantiate and condition the proposed device, shown schematically in FIG. 6

In some cases, especially when using masking transmitters, one of the most convenient modulation methods is a change in the tuning of a certain circuit, or antenna, causing a change in current, due to a transition from some

a resonance curve check to other points, as shown, for example, in FIG. 1, where A is the initial position and S and C are the extreme positions on the resonance curve during modulation. In the absence of transmission, the contour is adjusted according to point J, and during modulation at its maximum amplitude, the adjustment of the contour varies within the limits corresponding to the BC interval. Such modulation is inevitably associated with modulating not only the amplitude, but also the phase of the emitted oscillation — this is its disadvantage. In order to understand the significance of this drawback, the following considerations need to be taken into account.

First, it can be shown that a periodic change in phase is completely identical to a periodic change in the frequency of the emitted oscillation. For this, the emitted oscillation can be represented as some vector A (Fig. 2), which rotates clockwise with frequency and. If the observer rotates with this vector in the same direction, with the same frequency, then the latter will appear to him fixed. Any other vector of the same frequency, for example, vector B, is also pre-modulated, for example, on the left branch of the resonance curve, (point A), and modulation of circuit 2 occurs on the right branch of the resonance curve, (point B}, as shown in FIG. 5.

If the points on the resonance curves in both circuits are chosen symmetrically and move symmetrically during modulation, then at each moment the phase shift caused by circuit 7 is compensated for by phase shift by circuit 2 and, thus, during modulation, phase variations do not exist.

The subject matter of the invention. A device for modulating oscillation by changing the setting in

Features when radio telephoning using high frequency machines are different in that. that for modulation, two or more circuits are used, tuned and modulated in such a way as to eliminate phase changes, due to a change in the tuning of the circuits, for which each of the two interconnected circuits 7 and 2 includes the tuning circuit M in such a way that under the action of the telephone current, the period of natural oscillations of the primary circuit is lengthened, and the period of natural oscillations of the secondary circuit is shortened by an equal amount.

fip1

Fip2