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BA4
BA4/4
Time Integrator and G.T.S. Control Bay. Accommodates
relays for operation of 12 and 24 hour direct reading
clocks and G.T.S. units. Type 12 bay with BX5/15, BX5/16,
BA5/19, and 2 of each type BX5/13, BXS/14, BX5/17, BX5/18
and PA1/25, PA6/13, PA16/3. Broadcasting House Extension.
DD 1956/58. DD Spec 3.304. OBSOLESCENT.
BA4 Sub Group not available for new designs DD 1977.
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BA6 EQUIPPED LINES TERMINATIONS BAY
BA6/1
Equipped for four main OB channels and eight smaller
channels. Type 12 bay with AT2/5, CSM/2, DBA/1005, 8
ET/9A, FLP/5A, JF/111, 2 JF/115, KL/32A, 2 RM/4A, TP/10A.
Top cable entry. DD 1959. TI.L.4. OBSOLESCENT.
BA6/lA
As BA6/1 but for bottom entry. DD 1959. DD Spec 3.134.
OBSOLESCENT.
BA6/3
Incoming Lines Termination Bay for 30 circuits. Comprises
FW2/3 with MDP/5, PN3/23 with 30 amplifiers, PN3/23 with
30 equalisers in CH2/2, 2 U-1ink panels, 3 panels equipped
with LL/63RD repeating coils. DD 1967. OBSOLESCENT.
BA6/4
Outgoing Lines Termination Bay for 30 circuits. FW2/3
with MDP/5, PN3/23 with 30 amplifiers, 2 U-1ink panels, 2
attenuator panels, 3 panels equipped with LL/64RD
repeating coils. DD 1967. OBSOLESCENT.
BA6/5
Incoming Lines Termination Bay for equalising and
amplifying to OdB level 10 incoming PO lines. FW2/3A with
5 PA1/4l, 2 PS2/49, filters, coils, etc. DD 1968.
OBSOLESCENT.
BA6/6
Outgoing Lines Termination Bay for accepting a OdB signal
for transmission to 20 outgoing PO lines. FW2/3A with 2
AM7/2A, 4 PS2/49, filters, coils, etc. DD 1968.
OBSOLESCENT.
BA6 Sub Group not available for new designs DD 1977.
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BA7 EQUIPPED MOTOR BAY
BA7/1
Used with S.C.R.E.'s Desk DK3/1 at Bush House.
AMS/l, 4 MNA/3, 3 RLP/19A, 1 PA17/l and
DD 1957. DD Spec 3.143. OBSOLESCENT.
Includes 2
1 PA17/2.
BA7/2
Type 9 Bay with Siemens switching apparatus for selection

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