UN20
UN20/22
UN20/23
UN20/24
UN20/50l
UN20/502
UN20/503
UN20/504
UN20/50S
UN20/506
UN20/507
UN20L/SOB
- 404 -
unattended transmitters.
Based on UN18/l3A with
DD 1970. WITHDRAWN.
First used on
same chassis
Open University.
and index pegs.
Pre-hear Detector Unit for closing a pair of
contacts when the level on the pre-hear busbar in a
mixer exceeds -50dB. CHl/18C. DD 1972. DDMI
DDTM 3.115. EDI 1012l(1)NOV7l. ACO. OBSOLESCENT.
relay
sound
3.537.
Telephone Ringing Detector Unit, providing "call" and
"ring" functions for EMX telephone lines, with outputs for
local indicators and common buzzer. Printed circuit board
with mounting brackets to fit TMC type key. SCPD 1972.
OBSOLESCENT.
Bitstream Detector Unit, designed as an ancillary unit to
BAl/4 and BAl/5 to detect the presence of a 6.336Mb/s
bitstream. CH1/12A. DD 1972. OBSOLESCENT.
Processing Detector and Comparator Unit used in MN2M/SOS
to process the two input signals from UN13/S03 in detector
circuits with selected time constants and compare them in
a difference amplifier. CHl/12A, pegs 15, 29. DD 1965.
DD Spec 5.109. ACO. OBSOLESCENT.
Sub carrier
Detector
used
with
videotape
machines
to
measure differential gain of the four heads for lining up.
Also processes and adds stability markers to the video
feed to monitors. Printed card and connectors fitted in
191mm x 12lmm Eddystone box. DD 1965. WITHDRAWN.
Bar Amplitude Detector Unit used
amplitude of bar in test line.
DD 1965. ACO. OBSOLESCENT.
in MN2M/S06 to detect
CHl/12A, pegs 19,28.
Pulse Bar Ratio Detector Unit used in MN2M/S06 to detect
difference in amplitude between pulse and bar in test
line. CHl/12A, pegs 19, 30. DD 1965. ACO. OBSOLESCENT.
Non-linearity Detector Unit used in MN2M/S06 to
non-linearity of staircase waveform in test
CHl/12A, pegs 19, 2S. DD 1965. ACO. OBSOLEScENT.
detect
line.
Noise Detector Unit used in MN2M/S06 to detect noise on
blank line during field suppression period. CHl/12A, pegs
19, 27. DD 1965. ACO. OBSOLESCENT.
Detector Unit used in MN2M/508 to
pulse bottom received from UNl/S69.
DD Spec 5.103. ACO. OBSOLESCENT.
detect noise in sync
CHl/12A. DD 1966.
Vector Detector Unit. Accepts 1 or 2 PAL encoded colour
signals and produces the colour vectors as X and Y
coordinate video signals using either regenerated or
external subcarrier signals. Comprises DM1/S02, UN9/542,
UNl/540 and printed back board for mounting in PN3/23.
DD 1966. DD Spec 8.252. ACO. OBSOLESCENT.

104