Acoustical Manufacturing Co. QUAD MULTIPLEX DECODER, Инструкция, Страница: 4 / 16

lNSTALLATION
Preparing the FM Tuner
If the Serial No. of the Quad FM tuner is
above 19062 a switch is fitted near V6 (see fig.
1). When used with the Multiplex Decoder the
switch should be moved to the stereo position,
marked RED.
If the Serial No. of the Quad FM tuner is
less than 19062 the tuner should be modified as
follows:-
(1) Disconnect capacitor C33 (.040) from
pin 5 of valve V6 (6AL5). If this com­
ponent is left in position the lead wire
should be placed so that accidental
contact cannot be made with any other
part of the circuit. Replace C32 (47p)
by a capacitor of 15p.
(2) Remove the Brown audio lead from the
pillar tag at the junction of resistors
R20 (220K), R21 (100K) and capacitor
C34 (lOOOp).
(3) Connect the Brown audio lead via a
2.,2K resistor (Dubilier BTT or equiva­
lent) to pin 5 of valve V6 (6AL5). Keep
the resistor close to pin 5 (see fig 2).
Connections between units
The FM tuner - Multiplex Decoder - Quad
22 control unit connections are shown in fig. 3.
The Multiplex Decoder may be fitted on the
rear of the Quad FM tuner cover by removing
the tuner cover fixing screws and replacing them
through the holes in the sliding bracket under
the decoder cover (see fig. 4).
The optimum performance for the decoder
will be obtained in moderate temperature. If
the cabinet ventilation is such that the air in the
FM tuner compartment exceeds 40°C (104°F)
the decoder should be moved from the tuner
cover and placed in a cooler part of the cabinet,
e.g. near an air intake on the cabinet floor.
Page 3