FLl
FLl/4l
FLl/50l-508
FLl/S09
FLl/509A
FLl/509B
FLl/5l0
FLl/512
FL1/514
FLl/5I5
FL1/5I6
FLl/517
F'LI/5I8
FL1/Sl9
130 -
Directional Filter, 30dB, Bands
of
return
loss.
CHI/56
with
DD 1970. OBSOLESCENT.
IV and V, for measurement
4 type C connectors.
IF Filters used on television translators.
OBSOLESCENT.
DD 1960.
Comprises Bandpass Filtet and pulse-shaping network used
for linearity measurements on a staircase waveform. Basic
type. Suffixes indicate special uses. DD 1960.
DD Spec 9.13. ACO. OBSOLESCENT.
Filter, Non-linearity
of step heights of
approximately 600kHz.
x 57mm. DD 1969. DD
Measurement. Used for measurement
a
staircase
waveform.
Bandwidth
Ptinted circuit board 190mm x l2lmm
Spec 9.13. OBSOLESCENT.
Similar to FL1/509A but for 625 line standards instead of
405. Bandwidth 900kHz. DD 1960. OBSOLESCENT.
IF Filter used on television translators.
OBSOLESCENT.
DD 1961.
Non-linearity Measurement Filter used for measurement of
differential gain distortion. Constant resistance
band-pass filter, 75n, ceatre frequency 4.43MHz, bandwidth
O.~z.
111mm
x
60mm K 3Omm.
DD 1963.
DD Spec 9.94.
OBSOLESCENT.
Subcarrier Rejection Filter used to reduce level of
subcarrier in colour signal radiated from transmitters not
scheduled for colour traasmission by an amount sufficient
to render operation of colour receivers impossible. Small
box. DD 1966. DD Spec 6.114. ACO. OBSOLESCENT.
Notch Filter, Stop,
Incorporated 4 helical
DD 1965/68. WITHDRAWN.
used with EP7/50lA,
resonators. 483mm
EP7/50lD.
x 222mm.
IF Impedance Matching Filter used with EP7/50lA, EP7/S0lB.
Copper box 76mm x 51mm x 57mm. DD 1965/68. WITHDRAWN.
Notch Filter,
Incorporates
WITHDRAWN.
with EP7/S0lA, EP7/S0lB.
resonators. DD 1965/68.
Pass, used
2 helical
Filter and Bode Equaliser used in a SECAM to PAL
transcoder. Comprises FL4/556 followed by two variable,
non-resonant, Bode Equalisers with half loss frequencies
ot 0.5MHz and 1.OMHz. CEl/l2A. DD 1965/68. WITHDRAWN.
Vestigial Sideband Filter, 24MHz, used in Field Store
Converter with 3.3~s delay lines to change double sideband
signal
to
vestigial
sideband.
CH1/12.
DD 1965/68.
WITHDRAWN .

30