TM 11 - 5820-554-12
7-15. Items Comprising Power Supply PP -4 765/GRC-1 59(V)
Power Supply PP -4 765/GRC-159(V) 24-volt d.c. input
fied to accept this change of polarity.
Wrong polarity of connections will
a. Select a location in the vehicle, boat, or aircraft
destroy all four transistors in the power
for mounting the PP-4765/GRC-159(V) where it will
supply. As an added precaution, remove
be cool, clean, and dry as possible. Location under the
the fuses before making connections to
seat or on the passenger side of fire wall is usually
the terminal board.
They may be
DO NOT mount it in the engine
replaced after all connections have been
made and checked. After the power cable
b.. Determine the necessary length of power cable
and the 28-volt leads are connected,
to connect the power supply to the equipment. If the
replace the terminal board cover.
power supply is to supply voltages to the Collins
d. Before use with the Collins KWM-2/2A, adjust
KWM-2/2A and the Collins 351D-2 is used, cut the
the bias voltage as follows:
required length of cable from that furnished with the
(1) Set the MIC GAIN control fully counter-
mount. If the Collins 3511) 2 is not used, use a power
connecting cable such as Collins 440E-1. Wire color
(2) Set the EMISSION switch to LOCK.
code and pin-terminal interconnecting information is the
(3) Set the meter switch to PA PLATE.
same for the Collins 440E-1 as for the power cable
(4) Set the OFF-ON-NB-CAL switch on.
furnished as part of the Collins 351D-2. Other
(5) After a 2-minute warm-up period, the no
connections to the Collins KWM-2/2A may be made as
signal plate current, as monitored on the meter, should
shown in figures 3-1 through 3-6.
be approximately 40 ma. If it is not 40 ma, adjust
c. Remove the cover from the PP-4765/GRC-
BIAS ADJUST potentiometer R19 on the power supply
159(V) power supply terminal board, and make con-
until a 40 -ma reading is obtained.
nections to the terminal board (fig. 7-7).
1. DO NOT connect the PP-4765/GRC-
Operation of the power supply is controlled from
159(V) power supply to a 28-volt d.c.
switches and relays in the equipment for which the PP
source having transient voltages in
4765/GRC-159(V) supplies power. No other operating
excess of 50 volts. To do so will
procedures are required.
destroy the switching transistors.
7-18. Operator's and Organizational
2. Be sure to observe proper polarity of
the battery when making connections
Operator's maintenance instructions are covered in
to the 24-volt terminals of the power
supply DO NOT connect the PP-
4765/GRC-159(V)to a system which
has a positive ground unless the power
supply has been modi-
Section IV. POWER SUPPLY 1 2-VOLT D.C. INPUT
used, it includes a power cable for connection between
the Collins KWM-2/2A and the Collins 351-2
The Collins MP-1 converts 12-volt d.c. energy from an
combination and the Collins MP-1 supply. If the
automobile storage battery to B+ and bias voltages
Collins 351-2 is not used, use the Collins 440E-1 cable
necessary for operation of mobile amateur equipment
to connect the Collins MP-1 to the Collins KWM-2/2A.
such as the Collins KWM-2/2A. The Collins MP-1 can
be used in car, boat, or plane having a 12-volt d.c.
power system. If the Collins 351-2 mobile mount is