UN7/1
UN7/2
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UN7
UN7 KEYSWITCH UNITS
Used at Towyn and Penmon. DD 1958. OBSOLESCENT.
Keyswitch Unit to enable various
be supplied to Open University
test purposes. Switches logic
47t 85. DD 1971. WITHDRAWN.
combinations of tones to
distribution circuits for
of GE1/3. CH1/12A, pegs
=============:====================c=======================================
UN7 Sub Group not available for new designs. DD 1977.
UN8/1
UN8/4
UN8/5
UN8/6
UN8/7
UN8/8
UN8/9
UN8/l0
UN8/l1
UNS SIGNALLING UNITS
Signalling and Telephone Unit used on DK4/5.
OBSOLESCENT.
DD 1962.
Lamp Drive Signalling Unit on 76mm x 66mm plug in card.
Takes in a square wave and drives four lamps to give
flashing indication of fault conditions. DD 1965/6S.
WITHDRAWN.
Lamp Drive Signalling Unit on 76mm x 66mm plug in card.
Produces low frequency square wave for application to
UNS/4. DD 1965/68. WITHDRAWN.
Control Signalling Unit
transmitter/receiver via a
Radio Car. Controls UN8/7
DD 1965/68. WITHDRAWN.
for remote switching of a
line for communication with a
at the out station. CH1/1SE.
Slave Signalling Unit controlled by UN8/6. Sends signal
to UNS/6 when it receives adequate signal from the Radio
Car and then switches on the transmitter on receipt of a
signal from UN8/6. CH1/lSE. DD 1965/68. WITHDRAWN.
Three-tone Signalling Unit used to
signalling frequencies required for
Remote
Switching
System.
CH1/1S
1965/68. WITHDRAWN.
provide ~ of the 5
the WashfLrd-Cardiff
with
3
OS2/26.
DD
Two-tone Signalling Unit
2 of the 5 signalling
switching relays. CHl/l8
DD 1965/68. WITHDRAWN.
associated with UN8/8 to provide
frequencies and mount 5 tone
with 2 OS2/26 and 5 relays.
Line Bridging Signalling Unit used with
a Hughes Bridge Filtert OS2/26 and
CH1/lSA. DD 1965/68. WITHDRAWN.
UN9/l5.
a tone
Includes
switch.
Serck System Signalling Unit connected to the indicator
lamps of the Serck Switching and Supervisory System
between Manchester and Carlisle. The d.c. output causes
UNlM/65 to send a.c. signals to Newcastle to indicate the

77