MD3/9A
MD3/9B
MD030010 MD3/10
MD3/10A
MD3/10B
MD030011 MD3/11
MD030012 MD3/12
MD030013 MD3/13
Frequency Modulator. Same as MD3/9 with :t30 kHz peak
deviation and 97 MHz output frequency. Power requirements
+10 V. pcb 250mm x 145mm. Parent equipment TM3M/8B. DD
1984.
Frequency Modulator. Same as MD3/9 with :t12.5 kHz peak
deviation and 12.5 kHz audio bandwidth. Power requirements
+10 V. pcb. Parent equipment TM3M/8D. DD 1984.
Tone Modulator. This unit is part of the EP2M/7, audio
line signalling system. This unit generates two tones
anywhere between 6 KHz and 15 KHz with at least 200 Hz
spacing. These tones can be switched on or off
individually to form a signalling code. Programme passes
through a switchable L.P.F. and is then mixed with the
tones. CH1/65C. DD 1977. DDMI 6.318(78).
Tone Modulator G.T.S. This unit is used to send Greenwich
Time Signal (G.T.S.) information 'above' a sound programme
circuit. The signalling consists of switching one tone
with G.T.S. and at all other times this tone is off.
Another tone spaced 200 Hz away is used for monitoring the
condition of the transmission circuit for level or
complete failure. To convert froma MD3/10 to an MD3/10A a
board
3
has
to be
added.
The
tone
frequencies
and
programme bandwidth can be altered by changing a filter
(FL4/64A-L) contained in the MD3/10 and MD3/10A. Power
requirements +12 V at 100 mA, -12 V at 100 mA, +5 V at 400
mA. CH1/65C. Parent equipment EP2M/7. DD 1979. DDMI
6.353(80).
9.7KHz FM Tone Modulator. MD3/10 set up MD3/10B
for 9.6 and 9.8KHz tone (FL4/64D) frequencies, and then
modified to provide external input (9.7KHz FM) for tone 1
and internal tone 2 at 9.7KHz. The FL4/64D sub unit is
adjusted and two links on main board are replaced by jumper
lead which is also connected to the front panel monitor
point for tone 1 via a 10kQ resistor. Power requirements
as for standard MD3/10. 2U 'c' width brick with two
horizontally mounted pcbs. G06 connector. Parent equipment
EP2M/7. Sub-units FL4/64M. RD 1984.
4-phase DPSK Modulator. This unit is part of the EP2M/7,
Audio line signalling send equipment. It accepts tone(s)
from
the MD3/10,
Tone modulator
between 6-l5kHz.
It
modulates the tone(s) at a rate of 160 bauds using 4-phase
DPSK.
The modulated output is transferred to the MD3/10.
CH1/65C,
64 way G06 back connector.
DD 1977.
DDMI
6.349(80).
FSK Modulator. This unit accepts TTL clock and data
signals and produces a three tone audio FSK output. In the
lower band mode, at 50 bits/sec, the output is similar to
that of the TM1M/1 and the TM1M/2. In the high band it
operates at 110 bits/sec and produces output tones in the
region of 2.6-2.8kHz. +5V, -12V, OV. CH1/6 3. DD 1977.
DDMI 5.378(80).
Band 11 Frequency Modulator. Accepts an audio signal (mono
or multiplexed -stereo) and converts this to a frequency
modulated signal at a centre frequency of 10. 7MHz. Also
contains a f.c. system which may be used to stabilise the
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