SU111264A1 - Oscillator with variometer - Google Patents

Description

The subject of the invention is an autogenerator with capacitive feedback and a variometer as a tuning element, in which the destabilizing effect of the lamp on the frequency of the generated oscillations and the dependence of the amplitude of oscillations on the frequency are reduced.

Unlike the conventional three-point oscillator according to the Schembel scheme, in which the lamp-to-loop link does not change when the variometer knob is turned and does not remain optimal in the frequency range, in the described autogenerator, one of the lamp turn-on factors or P or P is variable and decreases with the introduction of a variometer setting, i.e. with a decrease in frequency.

FIG. 1 shows a circuit with a variable anodic bond and a constant grid bond, and FIG. 2 is a diagram with a variable grid coupling PC and a constant anodic coupling.

If the connection of the loop to the lamp is chosen optimal at the highest frequency of the range, as is usually done, then with decreasing frequency of the variometer L, the characteristic of the loop p increases and one of the links (PC or Pd) decreases.

As a result, higher frequency stability is provided when exposed to intra-tube and external mounting capacitances, and the amplitude of oscillations and the mode of the oscillator vary considerably in range. In fact, if we assume the resistance of the circuit Zo, Q-to-Ie, and the quality factor of the circuit Q., Then from the condition of the generator P,.) L, 5 ,, 1, it follows that the average slope is 1 о. and the cut-off factor of the anode current a,

WITH

r1

L: With

 have with

№ 111264

Such a change in the average steepness as a function of the frequency and cut-off factor of the anode current, and, consequently, the amplitude of the oscillations, can be considered insignificant compared to the conventional circuit,

for which a. , and 5 „,

1/0)

The last expression follows from the excitation condition under the condition of unchanged P and P bonds.

With the range overlap factor / (- 2, the frequency stability of the described oscillator increases 1.6 times. This can be seen from a comparison of expressions regarding frequency instability over the range for

D / 1 /,, "L DS,

the usual scheme-j-„- with f const and for the scheme,

/ /with

shown in FIG. I, -j- | RO, - If on

/

the highest frequency of Dianasone in both cases, P, Ra P, then at the lowest

frequency range instability of the described generator in,. , J., -, times less.

The proposed oscillator can be used in mobile radio stations and other devices, provided that the influence on the frequency of climatic and mechanical factors is reduced by technological and structural innovations to a degree comparable to the destabilizing effects of the lamp.

Subject invention

An auto-oscillator with a three-point variometer with a capacitive coupling, characterized in that, in order to reduce the destabilizing effect of the lamp on the frequency of the auto-oscillator, when using the variometer as an extension component, one of the coefficients of switching the lamp into the circuit (anodic or grid) changes and the other remains constant when the oscillator frequency is tuned.

 TO