MD2/501
MD2/502
MD2/503
MD2/503A
MD2/504
MD2M/505
MD2/506
MD2/507
MD2/508
MD3/1
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MD2
MD2 AMPLITUDE MODULATORS
Used in
DD 1958.
electronic
DD Spec 4.9.
facsimile transmission
WITHDRANW.
equipment.
Wideband Sound and Vision Modulator for RF distribution of
sound
and
vision
signals
and
as
a
test
modulator.
Provides double sideband suppressed carrier television
signals on any channel in Band I or Ill. Superseded by
MDl/502. DD 1959. DD Spec 4.9. ACO. OBSOLESCENT.
Modulator, Amplitude, Carrier used to mod~late a 30MHz
carrier with a composite television waveform for passage
through
NE4M/50l.
Includes
30MHz
crystal
oscillator.
CHl/12B,
pegs
14,
29.
DD 1965.
DD Spec 7.67.
DDHB 7.108. OBSOLESCENT.
Modified version of MD2/503 for use in C06/504.
standard video waveform and produces a 24MHz
modulated
double sideband
carrier.
CHI/12B.
WITHDRAWN.
Accepts a
positive
DD 1968.
Modulator, Amplitude, Subcarrier used
Self contained box, 57mm x 40mm x
mounting on a printed board in
DD Spec 11.21. ACO. OBSOLESCENT.
in colour coders.
19mm with pins for
CH1/12. DD 1966.
Transmitter Drive Amplitude Modulator used on BA13/509.
Standard 405 line modulator operating at IF of EP7/507.
PN3/23 with UN13/502, AT2M/9, MDl/503A (frequency
34.65MHz), MDl/503A (frequency 38.l5MHz), AT4/505. In
some installations 2 OS5M/502, 2 MDl/503B or, MNI/505A are
fitted. DD 1966. DD Spec 12.19. DDTM 12.6. OBSOLETE.
Carrier Amplitude Modulator similar to MD2/504 but
different input transformer and other components.
with
OS2/5l7.
DD 1967.
DD Spec 9.109.
OBSOLESCENT.
with
Used
ACO.
Similar to MD2/504 but with only two diodes for use as an
ON/OFF subcarrier switch in UNl/589. DD 1967.
DD Spec 8.278. ACO. OBSOLESCENT.
Amplitude Modulator used in EP14/504 to provide either
positive or negative modulation of a radio frequency input
by a video frequency input. CHl/12A. DD 1970.
WITHDRAWN.
MD3 FREQUENCY MODULATORS
Variable Inductance Frequency Modulator.
DD Spec 5.69. DDHB 5.33. ACO. OBSOLESCENT.
DD 1963.

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