11
INSTALLATION PREPARATION
The Commander II is factory wired for operation from an 234VAC line
. Operation at the full
rated output should not be attempted unless this line is capable of supplying at least 15 amps of
peak current. It is strongly recommended that you operate this amplifier from a 234VAC line.
The amplifier may be operated from a 117VAC power source capable of supplying at least 30
Amperes.
To configure the amplifier for 117VAC or 200VAC operation, remove the voltage selection
jumper cover on the rear panel of the amplifier and install appropriate jumpers (see illustration
below).
CAUTION.... BE SURE YOU HAVE REMOVED THE LINE CORD PLUG FROM
YOUR WALL SOCKET BEFORE REMOVING THE JUMPER COVER. IF YOU FAIL TO
UNPLUG YOUR AMPLIFIER, YOU WILL EXPOSE YOURSELF TO LETHAL VOLT-
AGES
. Install an appropriate plug on the power cord to mate with your wall receptacle.
If you change the operating voltage as described above, be sure to install the proper fuse.
The fuse is a type SFE, 15 Amp for 234 VAC & 200 VAC operation, 30 Amp for 117 VAC op-
eration
All Commander II amplifiers manufactured for export are wired for 200 or 234VAC, 50 or
60 Hz, depending on the final destination. No plug is supplied.
Location of your Commander II requires that no equipment be placed directly above it, as air
expelled from the tube exhaust can become quite hot. Allow at least 3 inches clearance on either
side of the unit and between other equipment. Extending the tilt bail located on the bottom of
the chassis improves the cooling airflow.
To switch from transmit to receive the Commander II requires a contact closure or keying
circuit capable of sinking 55ma of positive voltage (12 VDC open circuit) to ground. This con-
nection is made to the RCA jack on the rear panel marked RELAY. Read the manual that came
with your transceiver to determine the proper external connections. On some transceivers, this
is not provided, and an alternate circuit will be required. Always use shielded cable for these
connections.
Connect a good quality thruline Wattmeter between the amplifier output jack and the an-
tenna or dummy load using RG8 or better coax.
Connect the exciter (transceiver) RF output to the amplifier input using 50 ohm coax.
Connect a ground lead, as short as possible, from earth ground to the Commander II’s rear
panel ground terminal.
