SCIENTIFIC ABSTRACT NAKHMANOVICH, V.E. - NAKHODKIN, N.G.

• Document Type: CREST
• Collection: Scientific Abstracts
• Document Number (FOIA) /ESDN (CREST): CIA-RDP86-00513R001136020001-7
• Release Decision: RIF
• Original Classification: S
• Document Page Count: 100
• Document Creation Date: January 3, 2017
• Document Release Date: July 31, 2000
• Sequence Number: 1
• Publication Date: December 31, 1967
• Content Type: SCIENTIFIC ABSTRACT

sov/lo6-59-5-3/13
Amplitude and Frequency Distortions in Oacillators with Frequency-
Keying
the oscillator. For an oscillator having an inductive
"soft" feedback, the equation has the form (Ref 5)
x =- A(-r)cos (.r-V(T)] (1)
where the amplitude of the oscillation A(T) and the
phase v(T) are determined by Eq (2) and (3). Solution
of Eq (2) has the forin
A(-r) -Acm1 (4)
V cm
I + Ce
where Acm is the steady-state amplitude and C is an
integration constant given by
A2 AM 2
C cm - (6)
A(0)2
Card 3/8 where u is a parameter of the oscillator and is much

sov/io6-59-5-3/13
Amplitude and Frequency Distortions in oscillators with Frequency-
Keying
smaller than 1. Finally C is transformed into
C 1 - CX2
cx2 + x(0)2 1 2 Q X(O) (17)
i PAc
A4 - x(OF2 M b
A2 - X(O
cm _x )2
c
c
m
where x is the ratio of the grid-voltage to the cut-off
voltage of the,oscillator valve and Cx =W 0 2
Cj 0.1
C30l is the natural frequency of the oscillator tuned
circuit without the keyed capacItancePop the frequency with
the capacitance connected. Because C depends on the
value of x(O), the oscillation amplitude (after connection
of the capacitance)will change from a value Acm to a
value A(O) given by
Acm
Card 4/8 AM 'r 4 + C (18)

sov/lo6-59-5-3/13
Amplitude and Frequency Distortions in Oscillators with Frequency-
Keying
As time progresses, the value A given by Eq 18 tends to
Acm* Thus, parasitic amplitude modulation will be
produced. The maximum depth of modulation is found by
considering the two extreme values of C which the author
shows to be
1 - a2 w
Cmax (21)
d2 2
02
and
Cm'ax -1 (X W02 - W01- (22)
az W 2
01
For C = 0, there is no amplitude modulation. The
relative maximum and minimum ?'throws" in amplitude
Card 5/8 corresponding to the extreme values of C are

SOV/106-59-5-3/13
Amplitude and Frequency Distortions in Oscillators with Frequency-
Keying
,AA(O)min __ A(O)min - Acm
Acm Arm
AA(O)max
Acm
Card 6/8
A(O)jna3c -Acm
Acm
.._101 - 002 (23)
W 01
WOl - w02 (21k)
w02
Thus, the depth of the amplitude modulation does not
depend on the oscillator parameters but only on the
ratio of the frequency change to the generated frequency.
This conclusion is only valid ift (a) the capacitor is
fully discharged when it is connected to the circuit;
(b) the duration of the transients is small compared
with the duration of the elementary "frequency-pulBell.
Finally, the author investigates the frequency
distortion introduced by the keying. Ideally, the
oscillation frequency should switch Instantaneously
from one steady-state value to the other but, in fact,

sov/io6-59-5-3/13
Amplitude and Frequency Distortions in OncillatorE with Frequency-
Keying
the instantaneous frequency change differs from the
difference between the two steady-state frequencies by
an amount depending on the value of C. For C = 0, the
step change of frequency is
ACO = WI - W2 (27)
and the difference between the instantaneous step
change of frequency and the ideal change is zero.
For C = C,,,,,, the difference between the actual step
frequency change and the ideal Is shown to be
81OW = 3 2 (w0.2 w202
max Acmllp(wol - W02) _ + -
wo UTI (30)
This is illustrated in Fig 4 which shows an oscillogram
Card 7/8 which would be obtained if the oscillator output were

sov/lo6-59-5-3/13
Amplitude and Frequency Distortions in Oscillators with Frequency-
Keying
passed through an ideal discriminator. There are
4 figures and 5 Soviet references.
SUBMITTED: 25th July 1958
Card 8/8

7//0 2
AUMOR: Nakhmanovich, V. E.
28794
S/106/61/000/010/006/OC6
A055/A127
TITLE: Some possibilities of increasing the frequency stability of radio
transmitters operating in frequency telegraphy
PERIODICAL: Elektrosvyazt, no. 10, 1961, 67 - 69
TEXT: One of the methods of increasing the frequency stability of radio
transmitters in frequency telegraphy is based on the simultaneous existence of two
sia-ble frequencies in the exciter; to effect frequency keying, these two frequen-
cies are applied alternately to the output. Phase Jumps (up to 1800) occur how-
ever at the moments of switching and cause a widening of the spectrum of the ra--
diated frequencies. The author proves analytically that the width of this sDec-.
trum can be reduced considerably by an adequate control of the phase Jump. Let us
assume that the phase jump at the passage from one of the frequencies to the_of~her
is 4-66 and -W respectively. Fig. 1 shows the varilLtion of the frequency and
phase of the oscillations in the case of keying by IL sequence of dots. Analytical-
ly, these variations can be expressed as:
a(t) - Aosin[&)ot+e(t)] - Ao[sinabt cos 0(t)+cosujot sin 0(t)],(1)
Card 1,6

28794
3/106/61/000/010/006/006
Some possibilities of increasing the... A055/A127
G(t) =Mat -2) ato