Instruction manual

TM 11-6625-3017-14
Limiter and discriminator
All thirteen connections are soldered; the complete
unit can be removed after these have been unsoldered
by releasing four nuts from the top side of the chassis.
The cover is removable to give access to all the circuits
and presets.
200 kHz and 15 kHz low-pass filters
Either of these units can be removed by unsoldering
two connections and releasing two screws. The 200 kHz
filter is adjustable through holes in the top chassis
(immediately below extension board stowage).
Oscillator drive cord
The oscillator drive cord consists of a 3 1/2 ft length
of nylon cord arranged as shown in Fig. 5-4. Before
fitting, suspend the new cord with a weight of 4 lb (2 kg)
for 24 hours.
To fit a new cord:
(1) Turn the OSCILLATOR TUNE control fully
clockwise.
(2) Attach one end of the cord (X) to the correct spring
on pulley C.
(3) Pass the cord through the slot and once clockwise
round pulley C, then over pulley A and counter-
clockwise for three-quarters of a turn round the
bush to point X’.
(4) Ease the pin in the bush clear of the hole by means
of a small screwdriver. Loop the cord into the hole
and push back the pin to anchor it.
(5) Starting from point Y, wind the cord 7 1/2 times
counter-clockwise round the bush, take it over
pulley B, through the slot in pulley C and attach it to
the other spring at point Y’.
Fig. 5-4. Fitting drive cord
5.6 REPLACEMENT OF COMPONENTS
Fuses
The two fuses are fitted in fuseholders in the rear
panel. FS2 must never be changed without first switching
off the main supply, or circuit damage may result.
Transistors
Transistors that are mounted in holders may need
to be selected for low noise if replaced.
5-9