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phase difference between suitable picture frequency pulse
trains into d.c. error signals.
supplied by two UNl/52l. Output: error signal to UNl/5l9.
DD 1962. DD Spec 8.117. ACO. OBSOLESCENT.
Mains Phase Discriminator.
phase difference between incoming field frequency pulses
and a reference sine wave into an error signal. Presence
of a further input prevents operation. CHl/12A. Input:
Pulses from UNl/52l and 6V 50c/s reference. Output: Error
DD Spec 8.113.
Line Discriminator and Oscillator. Part of UNl/522.
Converts phase difference between suitable line frequency
pulse trains into d.c. error signal which with other error
signals varies the frequency of its twice-line-frequency
output. Presence of a further input prevents operation
and allows other discriminators to control output
frequency. CHl/12A. Input: Pulses from two UNl/52l and
error signals from UNl/5l7 and UNl/5l8. Output: IV at
twice line frequency at 75~ to UN9/5l5. DD 1962.
DD Spec 8.114. ACO. OBSOLESCENT.
Local Sync Delay Unit
DD 1962. DD Spec 8.115.
Sync Separator. Two form part of UNl/522. They convert
incoming video waveform into line frequency and picture
frequency pulses for use elsewhere in UNl/522. CHl/12A.
Input: Composite video or mixed sync at standard level.
Output: Picture pulses (odd or even field) to UNl/5l7 and
UNl/5l8 and line frequency pulses to UNl/5l9. DD 1962.
DD Spec 8.116. ACO. OBSOLESCENT.
Picture Synchroniser for bringing two independent pulse
generators smoothly into sync at a given point. (Known as
Inputs: (1) local sync
pulses 0.2 to 3V p-p. (2) Remote composite video 0.2 to
IV p-p of syncs. Outputs: (1) IV p-p from 750 into 75~ at
twice line frequency (c. 20,250c/s) to local pulse
generator, or (2) as (1) but balanced and ur.,arthed for
feeding via line and remote AMl/506 to remote pulse
generator. Includes UN9/5l5, UNl/5l7, UNl/5l8, UNl/5l9,
DD Spec 8.120.
DDHB 8.122. ACO. OBSOLESCENT.
Electrically as UNl/S22 but mounted
for OB use. DD 1963. DD Spec 8.120.
in modified CHl/18E
Sync Pulse Separator Unit used in PAl/5l3. Input of IV
d.p.a. video signal gives separated sync pulses at 2V
amplitude into 750. All standards and also 625/525 NTSC
colour signal. CHl/12A, pegs 3, 7. DD 1963.
DD Spec 8.140. DDHB 8.140. ACO. OBSOLESCENT.
Return Loss Measurement Set for
50Hz to 5MHz or video standard
waveform, using an