SU27112A1 - Method for single-band telephony - Google Patents

Description

Transmission without a carrier frequency by one sideband when applied to short waves in cfioeM practical implementation encounters serious difficulties associated with the multiple modulation necessary for spreading the bands and, accordingly, a large number of stages, filters, etc., making devices are bulky and unstable. All this leads to the fact that single-band transmission on a short wave has not yet found wide application in practice, despite the significant advantages that it has. rymi taka re; Acha possesses in comparison with ordinary.

The present invention, which is a single-way radio telephony method, aims to eliminate these drawbacks.

The drawing shows a diagram of the device for single-band radio telephony, made by the proposed method.

On the circuit. The following symbols are used: 1-source of sound frequency and filter of sound frequency for passing the band 200-3000 lane, / sec; 2-first balanced modulator according to the scheme Sag-sona; 3-frequency filter for single band selection; 4 - Carsona second balanced modulator; 5-: Hilter,

low-frequency for the band 200 - 3000 lane / sec; 6 Third Balance Module Carsona; 7-1th intermediate frequency oscillator; 8-circuit tuned in resonance with the generator circuit 7 to the intermediate frequency 9-generator high frequency cuj, stabilized by quartz; 10-loop tuned to resonance at the frequency oui of the generator 9; 11 low frequency amplifier; 12 - Carsona 4th Balance Module; 13 output circuit.

The operation of the circuit implemented according to the proposed method is as follows: the low frequency band Q 200-3000 is supplied to the balanced modulator 2

lane / sec and intermediate frequency; after a balanced modulator 2, a current of the form is obtained: / 1 U1 sm cot sin ((-f-Q) t-

t- - cos (o

Q) t.

Filter 3 passes only the upper band Ji cos (o) -f-Q), which leads to the balanced modulator 4; in addition, module 4 is supplied with current from circuit 8, tuned to the frequency q). The current in the circuit 8 1U with respect to the current of the generator circuit 7, as follows from the theory of coupled circuits, will be shifted in phase by III; after modulator 4

therefore, we get the current type:

   / 2 t / 2 cos ((i- | -Q) t COS (ttt -y

COS {2.C) 4-Q) t-b COS Qt.

; Filter 5 only passes the low frequency band / 2 cos Ot, which is supplied to the modulator; This same balanced modulator b is supplied with current from circuit 10, which is tuned to resonance with the generator circuit 9 of high frequency j) i. If we assume that the current in the generator circuit 9 will be of the form: sin ш, t, then in the circuit 10 the current will be of the form cos ш t; after the balanced modulator 6 in the output circuit 13, a current of the form cos-oDit cos Qt- is obtained. From the low-frequency source after the filter 1, the current is also supplied through the amplifier 11 to the balanced modulator 12, to which the high-frequency current is simultaneously supplied from 9; after the balanced modulator 12, therefore, in the output circuit 13; a current of the form is obtained: 4 L sin) i t sin W. The current in the output circuit 13 will be: / 4 -j- 4 + / h cos о) t. cos Qt - | - J.1 sin O), t. sin Qt J cos (twi -jy- Q) t, T.-e. only one frequency band is obtained. If you wish, you can only get the lower band. To do this, you need to take in the circuit; Thus, in the output circuit 13, it is possible to obtain only one modulation band at any high frequency ' j without further multiplying the frequency and without multiple modulation. The Bte device up to circuit 13 can be assembled at low power with amplifying lamps, which should be a fairly compact device, in the future it comes down to simple amplification, as in conventional transmitting devices.

The low-frequency amplifier 11 and its purpose is to equalize the amplitudes of the low-frequency voltages Q of the modulators b and 12.

The subject matter of the invention.

A method of single-sided telephony, mainly on short waves, characterized in that the currents of the audio spectrum limited by the filter Q are fed to the first balanced modulator according to the Carsona scheme, to which n is simultaneously applied, of intermediate purity, then the modulated current is passed through an intermediate filter frequencies that pass only one modulated frequency band, and then the filter is fed to the second balanced modulator, to which also simultaneously, a current of the same intermediate voltage is supplied Estots w, but shifted relative to the current of frequency w, supplied to the previous balanced modulator by 90 °, at which the current modulated in the second balanced modulator passes through a low-pass filter that passes the audio frequency spectrum, then goes to the third balanced module The torus, to which the high-purity current Q is also supplied, at which the current of the same frequency (Uj, but shifted by 90 ° with respect to the previous one) is simultaneously supplied to the fourth balanced modulator, to which the spectrum currents also sound parts from O, after the first audio frequency filter, the modulated currents from the third and fourth balanced modulators are added or broken, 1 is read in the output circuit connected to the output circuits of these modulators.