Installation - Racal Instruments RA-117 User Manual

5. Installation

1. After carefully unpacking the receiver, remove the dust cover and make sure that all
valves and screening cans are firmly in place and that no packing material remains
within the tuning mechanism.
POWER SUPPLY.
2. Ascertain that the mains transformator is set to the appropriate voltage tapping. This
is carried out by means of soldered connections to the transformer. A power lead is
permanently fitted to the receiver which can be connected directly to the power supply.
Check that the terminals HT1 and HT2 situated on the main chassis are linked (unless
the L.F. Converter is in use).
FUSES.
3. Ensure that the rating of the supply fuse and the H.T. fuse correct wiz:
AERIAL.
4. The impedance at the aerial (antenna) input plug is designed to match into a 75-ohms
unbalanced transmission line. The cable termination supplied with the receiver can
bee provided with alternative sleeves to enable it to be used with a type UR.18 or
UR.70 cable or similar cables of nominal diameter 1/2-in or 1/4-in. respectively.
AUDIO OUTPUTS.
5. A number of audio outputs are available to give the following facilities.
(1) The two telephone jack sockets situated on the front panel are connected across
one of the 600 Ohms, 3mW outlets.
(2) The following outputs are connected to the terminal strip at the rear of the
receiver:-
(a) Three 600-ohms outlets at 3mW.
(b) One 3-ohm outlet at 1W.
(c) One 600-ohms outlet at 10mW. This output is controlled by a preset A.F.
LEVEL control on the front panel and is independent of the outputs previ-
ously described.
100 kc/s I.F. OUTPUT.
6. The connection consists of two coaxial plugs connected in parallel to the 100 kc/s
output. The total load should not be less than 75-ohms (e.g. with outlet loaded by
75-ohms, the other can be can used as a high impedance source).
EXTERNAL INPUT/OUTPUT CONNECTIONS.
7. The following input and output connections are available on a panel at the rear of the
receiver (fig.1):-
Supply fuse 2A
H.T. fuse 350mA, anti surge.
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