~7
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AM7/4D
As AM7/4B, but modified for use in areas of high MF field
strength. DD 1972. OBSOLESCENT.
AM7/6
Receiving Line Amplifier used to raise level of received
tone from UN8/8, UN8/9 for operation of UN20/9 on
Washford-Cardiff
Remote
Switching
System.
CHl/18.
DD 1967. WITHDRAWN.
AM7/7
Line Amplifier used in PA6/57. Gain: 20dB. Output: +24dB
into
600~.
Z
in:
lO~,
External
output
transformer.
BBC/ISEP printed circuit board with 25 way plug. Coding
positions 3, 17, 19. DD 1968. DD Spec 1.55. DDTM 1.64.
ACO. OBSOLESCENT.
AM7/8
Internal Line Sending Amplifier comprising two identical
amplifiers utilising NEl/7 each with a voltage gain preset
between 26dB and 46dB. Used as output amplifiers for
stereo sources such as tape machines. Includes supply
voltage regulator for operation from station 50V battery.
Printed board, l40mm x 178mm with ISEP 25 way connector.
Code pegs 3, 7, 23. DD 1968. ACO. WITHDRAWN.
AM7/8A
Internal Line Sending Amplifier, comprising two identical
amplifiers utilising NEl/7, each with a voltage gain
preset between 26dB and 46dB. Supersedes AM7/8. Used as
output amplifier for stereo sources such as tape machines.
Includes supply voltage regulator for operation from
station 50V battery. Printed circuit board l40mm x l78mm,
with ISEP 25 way connector. DD 1969. DD Spec 3.488.
DDHB 3.99. OBSOLESCENT.
AM7/9
4-wire Termination Line Amplifier used to make good up to
30dB losses in a telephone line for connection to NE2/l
associated with EP2/l. CHl/18C. DD 1969. WITHDRAWN.
~7/50l
Video Sending Amplifier with l2dB fixed gain. CHl/3
chassis. Mains operated. Input: OdB high impedance.
Main output +12dB into 75~ Mon. output; -15dB into 75~.
Weight: 5.7kg. DD 1958. DD Spec 8.27. DDHB 8.74. ACO.
OBSOLESCENT.
AM7/502
Line Sending Amplifier with switchable gain and output
impedance. Replaces TV/SA/lA. Mains operated. CHl/9D
chassis. Input: standard IV video signal. Output:
Balanced or unbalanced, IV or 2V between each leg and
chassis, increased to 3V or 5V for emergency use, with
impared performance. Z in: 75~ (37.S~ at highest gain).
Z out: Adjustable from 70~-180~ balanced or 75~
unbalanced. DD 1959. DDMI6.79. OBSOLESCENT.
AM7/S03
Line Sending Amplifier, 26dB (Narrow Band) for low quality
vision circuits e.g. cueing. Mains operated. CHl/12A.
Two balanced outputs each of 5V peak to peak into 50~ from
50~
source.
Z
in:
high.
DD 1962.
DD Spec 8.88.
DDHB 8.131. OBSOLESCENT.
fu~7/505
High Level Sending Amplifier. Gain
rel. to IV p-p. Mains operated.
2SdB. Output: +12dB
CHl/26B. DD 1965.

24