Procedure
Set the OFF/ON switch to the ON position.
Remove the front panel by releasing the retaining pin through the access hole on the right
hand edge of the cover. Hinge front panel cover to the left and remove.
Release the two M4 screws on the top edge of the front panel and lift the top cover to the rear
to disengage the interlocking edges of cover and frame.
All modules are now accessible and the plug-in modules not secured to the frame can be lifted
with the aid of the Module Extractor Tool. The TX PA, RX AF, High Power Modulator and 10V
Regulator modules can be withdrawn after releasing their securing screws. The RX RF Module and
the TX and RX Oscillator Module can be withdrawn by removing the M2,5 pillars securing them to
the Mother Board. The plug-in 10,7 MHz Crystal Filter is released by removing the two M3 nuts and
washers on the underside of the Mother Board.
Access to the underside of the Mother Board (secured to the frame by eleven M3 x 8 mm screws)
is obtained by removing the bottom cover; removal of the bottom cover is identical to that of the
top cover.
CAUTION 2
A poor thermal bond between the high current modules and the frame
can cause very serious damage.
Module Replacement
When replacing modules or thick film circuits which are bolted to the main frame, ensure the
mating surfaces of the frame pedestals and the modules are thoroughly clean and are lightly coated
with thermal grease. Before securing a module to the frame, check that it is correctly seated.
See also Recommended Servicing Compounds.
Interchangeability of Covers
As the Cover Assy. (2) and the Cover (3) are physically interchangeable, the cradle can either
be mounted on or suspended from any suitable flat surface. (See Note in Section 2).
CRYSTAL INFORMATION
NOTE: Specifications apply to the UK only, information for other areas being provided on
request. Failure to fit the crystals specified for a particular area may infringe type
approval regulations and/or temperature environmental requirements.
Receiver
Band
Carrier
Freq. (fc)
Crystal
Freq. (fx)
Crystal
Range
Crystal
Spec.
A
148 to 174 MHz
fx = fc — 10,7
45,76 to 54,55 MHz
T71
3
M2
138 to 141 MHz
49,56 to 50,56 MHz
T71
fx = fc +310,7
E
68 to 88
MHz
fx = fc + 10,7
39,35 to 49,35 MHz
T71
2
P8
96 to 106 MHz
f
x
= fc — 10,7
42,65 to 47,65 MHz
T71
C
117 to 137 MHz
2
f
x
= fc
10,7
35,43 to 42,10 MHz
T71
3
4.5
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