- 1 -
AMl MISCELLANEOUS AMPLIFIERS
Effects Amplifier. Continuously variable treble, bass cut
and boost and two steps of 'presence' boost. Gain: zero
for flat response, Z in and Z out; 600n. Normal input
level: -20dB. CH1/8 chassis. Superseded by AM1/4.
DD 1961. DD Spec 3.306. DDHB 3.57. OBSOLETE.
Amplifier, dB Meter. Used on PA6/15 and PA6/16 in OT1/3
to feed an external dB meter. Plug-in printed wiring
card. Superseded by AMl/36. DD 1961. OBSOLETE.
Tone Amplifier used as output amplifier in OSl/l.
CH1/18C. Output: OdB into 600n with 1.8dB input level. Z
out: <7n. DD 1962. DD Spec 3.385. ACO. OBSOLESCENT.
Constant Volume Speech Amplifier for balancing
automatically speech levels over public telephone systems
prior to recording. Provides constant output level of
-3dB within t1dB for maximum variation of input levels of
40dB with bandwidth of about 280Hz to 3650Hz. Switch
gives compression range of 40dB, 30dB, 20dB, 10dB. Input
level not greater than OdB. Comprises PN3/23 with UN1/23,
UN1/24, AM6/1, FL2/2, AM4/6, UN9/7, PS2/49. DD 1963.
DD Spec 2.217. DDHB 2.143. TI. OBSOLESCENT.
As AMl/6 but fitted with switch for
rA~/60. Supersedes AM1/6. DD 1968.
use with or without
Intercom Amplifier normally used with AM8/8 on PA8/197A.
Gain is 50dB to 70dB determined by external resistor.
Bass cut at the higher gain. 102mm x 25mm x 76mm plug-in
chassis. DD 1963. DD Spec 3.395. ACO. OBSOLESCENT.
Motor Drive Amplifier used in EP5/501 to drive the iris
motor of the 16mm vidicon te1ecine projector. Provides
+llV to -llV d.c. for a 3W motor from a control voltage of
-2.5V to -12V d.c. Includes PS2/22A. CHl/12A. External
24V supply from PS2/l3F normally. DD 1964. DD Spec 7.39.
DDHB 7.73. OBSOLETE.
Response Selection Amplifier used to modify the frequency
response of a channel. Includes narrow notch circuits to
eliminate hum, followed by a modified AMl/4 circuit,
switchable LP filters to eliminate TV whistles etc., and
an output amplifier. Mains operated. 483mm x l33mm panel
DD Spec 3.418. DDHB 3.85. ACO. OBSOLESCENT.
As AMl/9 but mounted in CS2/2B. DD 1966. OBSOLESCENT.
Response Selection Amplifier for shaping frequency
response of circuits. Provides frequency control per
octa~e. Modified commercial design. Portable. DD 1965.
ACO. WITHDRAWN .