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AM4
distributing colour television signals in
CH1/12A. Pegs 6, 31. Superseded by AM4/519.
DD Spec 8.223. DDHB 8.212. ACO. OBSOLESCENT.
RGB form.
DD 1966.
AM4/520
Amplifier, Distribution, 6dB, RGB. Identical with AM4/519
except for closer tolerances on output resistances for
distributing RGB signals. CH1/12A, pegs 18, 37.
Superseded
by
AM4/519.
DD 1966.
DD Spec 8.270.
EDI 10119(1)JAN72. ACO. OBSOLESCENT.
AM4/523
Test-signal Distribution Amplifier, as AM4/515 but with
high impedance input to permit "loop-through" working, and
with output connections via multi-way socket to permit
quick
changing of
amplifiers.
Designed
to
work
with
Termination Panel PN3A/42. DD 1971. OBSOLESCENT.
AM4/528
15dB gain Video Distribution Amplifier with 6 outputs at
OdB and high impedance balanced input. CH1/65A. DD 1975.
CANCELLED 1977.
AMS MULTI-PURPOSE AMPLIFIERS
AMS/1
Used as line receiving amplifier at battery operated
stations. Similar to GPA/4A but with transistors and
printed wiring. W.V.G.: 20dB to 60dB in 0.5dB steps. Z
in and Z out: 600~. Transistors: 4 GET104, 2 GET105,
GET106. First used in Cardiff. Units modified on
installation at SW and VHF stations to prevent RF pick up
are indicated by the letter A marked on the unit.
DD 1960. DD Spec 3.242. OBSOLESCENT.
AM5/2
Used on PA6/15 and PA6/16
card. Gain: 25dB. Z
Transistors: 3 OC71,
DD 1960. DD Spec 2.172.
in OT1/3. P1uggab1e wiring 4
in and Z out: 600~ (balanced).
2 OC84. Superseded by AM2/1.
DDHB 2.109. OBSOLESCENT.
AM5/3
Used on PA6/15 and PA6/16. P1uggab1e wiring card. Gain:
30dB. Z in and Z out: 600~ (unbalanced). Transistors: 2
OC71. Superseded by AM2/2. DD 1960. DD Spec 2.172.
DDHB 2.109. OBSOLESCENT.
AM5/4
Provides maximum output of 2 watts into 3~ from low
impedance for an input voltage level of -10dB. Gain
variable in 2dB steps over 46dB range. Z in: high. Mains
operated. CH1/18D. Used to feed 3~ or 15~ loudspeakers.
DD 1963. DD Spec 3.365. DDHB 3.69. ACO. OBSOLESCENT.
AMS/4A
As AMS/4 but with different output transformer for
of 50~ or 200~. Used to feed ring mains and to
programme to line at higher output than normal. DD
DD Spec 3.365. DDHB 3.69. OBSOLETE.
loads
send
1963.
AM5/5
Used as intercom, medium-quality loudspeaker amplifier
powered from 24V or 50V relay supplies. Maximum output

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