Digital Timecode Generator. Crystal oscillator driving a
seven day digital clock with output in serial form on
5 pairs. May be set by thumbwheels, or automatically from
a MSF receiver. Seconds are synchronised to the Gents
clock system. Power requirements 5V d.c. lA. CHl/64D. DD
MSF Clock. This equipment receives, via an RCl/22,
demodulated time code data from the 60kHz frequency
transmission of MSF, Rugby. This data is decoded and used
to reset an internal clock every minute. Extensive checks
are made on the incoming data to eliminate erroneous
setting of the clock which free-runs using an internal
crystal reference when the Rugby signal is absent or in
error. The internal clock has a calendar correct to the
year 2100 and unpredictable events such as BST/GMT changes
are implemented on receipt of the MSF data. The current
date/time is displayed on a front panel indicator and is
available multiplexed onto a l6-bit parallel outpu t. The
unit is designed to supply date/time information to the
CEEFAX origination equipment. Power requirements Mains,
50VA maximum. lU high bay mounting chassis. DD 1978.
Signal Generator. This unit generates three digital
signals. Two are sampled sine waves, the other a pseudo
random sequence. Power requirements +5V. CHl/54J. Parent
equipment TM4/3. RD 1978.
NICAM 3 Multiplexer. This unit extracts PCM signals from
up to three (plus spare) CD2M/17's and multiplexes them
into a 2048kbit/s bitstream in HDB3 form. It provides
l6MHz clock signals to three CD2M/17's. Power
requirement +5V at 200mA, +18V at 55mA, -18V at 135mA.
6.377(80). DDHB 6.222(83).
NICAM 3 Multiplexer. This unit can multiplex PCM signals
in two ways. The first is applied with the NICAM 3
insertion equipment CD2/23 Options 3,4 and 5. The unit is
provided with 2048 kbit/s NRZ bitstream containing X,Y and
Z 'stereo' bitstreams. The X,Y or Z bitstreams can be
'overwritten' by either a local or remote coder bitstream.
It generates a 2048 kbit/s bitstream in HDB3 form. The
second application is when it is used in the NICAM 3 coder
CD2M/17A. It extracts PCM signals from up to three
CD2M/17's (plus reserve) and multiplexes them into a 2048
kbit/s bitstream in HDB3 form. This unit also provides the
NICAM 3 16MHz system clock. Power requirements +5V at
200mA; +18V at 100mA. -18V at 100mA. CHl/64J. Supersedes
GE7/9. Parent equipment CD2M/23 Options 3,4 and 5,
CD2M/17A. DD 1981. DDHB 6.223(83). EDI 10458(1) AUG 82.
Data Generator. For use with HP 1645A Data Error Analyser
to test data transmission links. The equipment consists of
a Coder and Power Supplier contained in a portable carrying
case. The power supply is 230V AC via a flying lead ending
in a domestic 3-pin mains plug. Power requirements 230V
AC. Carrying case CS2/27C. Sub-units PS2/187D and CD2/22.