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MN4 AUDIO FREQUENCY MONITORS
(Sub Group previously defined as "Programme Monitors" DD 1977.)
FM Demodulator used in EP1/3 to reproduce the modulating
signal from a 10.7MHz IF signal. CH1/27 with UN15/lA,
AM6/2, AMlO/4. DD 1965. DD Spec 5.89. OBSOLESCENT.
Audio Programme Monitor for scanning three programmes in
turn, the selected one being transmitted via OSl/3 to a
telephone circuit. Printed board. DD 1967. WITHDRAWN.
MN5 VIDEO FREQUENCY MONITORS
(Sub Group previously defined as "Sequential Monitors" DD 1977.)
Sequential Monitor for sampling each of 6 logical inputs
in turn. Triggered by shift pulses from OSl/3. Printed
board. DD 1967. WITHDRAWN .
Sequential Monitor for two or more audio inputs. Has
facilities for omission of temporarily unused inputs and
holding any input for special monitoring. Rate of
monitoring can be set to dwell between 10s and 45s on each
monitoring point. Suffixes indicate number of inputs from
2 to 14. PN3/23 with GE2/4 and one UN2l/l9 per input.
DD 1969. DD Spec 3.503. DDTM 3.106. EDI 10075(1)DEC70.
PCM Coder Sequential Monitor used in CD2M/2 as an analogue
comparator and to scan the 13 audio channels in the PCM
encoder. Generates an alarm signal if the input audio
signal differs significantly from a reconversion of the
output of C01/2. Printed board with 33 way ISEP plug.
DD 1971. CANCELLED.
MN6 WAVEFORM MONITORS
Used in vision and lighting control rooms in conjunction
with Pye picture monitor type 2780. 356mm x 86mm x 625mm.
251b. 75 watts. Valves: 4 E88CC, l2AU7, 2 Z759, 2 l2AT7,
2 l2AX7. 85A2, CV140, 12BH7, EY51, CRT DG.16-22. DD 1959.
DD Spec 9.9. DDHB 9.117. ACO. OBSOLESCENT.
Modified MN6/50l for mounting above associated picture
monitor instead of alongside. DD 1963. DDHB 9.117.