20:1 Direct Injection Box. Box contains input and output
(JACK IN, XLR(M) OUT) and special safety transformer,
AL 103 SP to provide interface from commercial to BBC
equipment. 150mm x 80mm x 50mm Box. Sub-units AL 103 SP
Transformer. DD 1981. DDMI 3.709. EDI 10453(1) JUL 82.
Telephone Effects Unit, consisting of MJS Telephone Effects
Generator, 3 x UN21/60 Telephone Select Units and a
Stabilised Power Supplier PS2/303. The unit is portable
and housed in a 3 U case. The unit provides full telephone
interconnected and conversations held between them,
together with full tone and ringing effects selectable to
requirements +24 V and +5 V. 3 U 19" Case W483 x H 133 x
D 254 mm. Sub-units MJS Telephone Effects generator (not
Caption Synthesiser Effects Unit, used in PA18L/529 to
process a monochrome caption infill signal and pr oduce
independently determined letter and background colours.
Unsupported 4U high printed circuit board of binary metric
modular chassis system. DD 1975. DDMI 8.545.
Synthesiser specifically for use with the Caption Insertion
Equipment PA18M/530. D.D. Change Form 125 47 details the
modification which enables blanking and clamp pulse
generation during the sync pulse period. Power
requirements +12V and -6V at 300mA. Unsupported 4U p.c.b.
to fit PN3/54. DD 1977.
Desaturator Effects Unit. Part of the UN4M/511P. CH1/12A.
DD 1977. DDMI 9.229(77).
Desaturator Effects Unit. This unit reduces the amplitude
of the chrominance on a coded signal. The reduction may be
coded from 0 to 6dB. An optional internal connection
enables the burst to be left unchanged when necessary. The
unit contains a UN4/510 and a PS2/182 in a carrying case.
CS2/17B. DD 1977. DDMI 9.229(77).
95 x 76mm.
As UN5/3 but with deeper diecast box. 121 x
Switching Signalling Unit. The unit encodes switching
information from two independent, and one of seven grouped,
inputs and produces signals at 6-0-6 voltage levels for
transmission on telegraph circuits. The complementary
receiver is also within the unit giving decoded outputs in
the form of changeover relay contacts. CH1/64J. DD 1976.
DDMI 2.435(76). DDHB 2.428(77).
Relay Switching Unit. This unit is an active encapsulated
circuit providing the energising current for a SO volt
relay when an earth is applied to one of its terminals.
encapsulated assembly approximately 16mm x 14mm x 9mm. DD
1976. DDMI 3.636(77). DDTM 3.196(77).