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UNl MISCELLANEOUS UNITS
Consists of two magnetic
Transductor MFB.179. Used
Llangollen on P.O. lines.
amplifiers using Elliott
for lightning protection at
Mounted in CT2/7. DD 1959.
on PA1/24 to detect the 1975c/s
DD Spec 2.158.
Unit, Magnetic Amplifier and Power Supplier, used for d.c.
signalling over P.O. lines where lightning protection
precautions have to be taken. Consists of unearthed 40V
power supply switched on by a relay for sending signals to
line, and a magnetic amplifier for telemetering line
current to a remote meter. Mounted in CT2/7. DD 1959.
DD Spec 2.134. TI.L.4. OBSOLESCENT.
Used with PA6/46 at Meldrum. DD 1961. WITHDRAWN.
Unit, Magnetic Amplifier and Relay used to amplify and
detect d.c. signals on lines subject to lightning strikes.
Provides a voltage barrier of 20kV d.c. between P.O. cable
and station apparatus. Mounted in CT2/7. DD 1959.
DD Spec 2.133. T1.L.4. OBSOLESCENT.
Transistor/Relay Switching Unit used for remote control of
unattended transmitters by small direct currents over
music lines without phantom circuits. Uni-directional
current operated. DD 1959. WITHDRAWN.
Similar to UN1/5 but with two magnetic amplifiers and
relays. DD 1959. DD Spec 2.133. TI.L.4. OBSOLESCENT.
Similar to UNl/6 but uses miniature enclosed relays and is
bi-directional current operated. DD 1959. WITHDRAWN.
Tone Detector Unit used on VF Switching System. Normally
mounted on PN3/18. Transistors: 4 OC203. DD 1960.
DD Spec 2.174. DDHB 2.111. TI.L.2. OBSOLESCENT.
Microphone Distribution Unit giving outputs of 30~, 30~
and high impedance from 30~ microphone input. DD 1960.
Microphone Adaptor Unit
DD 1960. OBSOLESCENT.
with various output plugs.
Unit, Amplifier (Magnetic), Power Supplier and Relay used
for lightning protection at Me1drum. Similar to UN1/3 but
with relay section added. DD 1960. OBSOLESCENT.
Unit, Return Loss Bridge used to determine a figure of
merit from terminating impedances in terms of magnitude of
reflected wave. DD 1960. WITHDRAWN.
Unit, Equaliser used on PN3/l9 with PS3/8, UN10/4, GPA/4A.