SBE SB2-LA - Mobile Installation; Tuning and Operating Procedure

CAUTION
Do not operate the SB2-LA into an antenna load with a standing-
wave ratio greater than 2:1. The equipment will not load properly
and damage to the antenna cable can result. Never operate the
amplifier at full load with a continuous tone for more than 30 seconds.
The tubes and power supply may be damaged. Never operate at
power inputs higher than given in the SPECIFICATIONS section of
'this manual; the life of the tubes will be greatly shortened. Do not
replace the fuse with a slow-blow type or with a size larger than
15 amp. Always reduce power by decreasing drive to the amplifier,
never by decreasing antenna loading.
C. MOBILE INSTALLATION
Mobile operation of the SB2-LA linear amplifier is entirely practicable by use
of the SB3-DCP DC/AC inverter. Installation may be made in any automobile
with a negative ground 12-volt supply. The amplifier and inverter are normally
installed in the trunk of the vehicle; installation in the cab is not advised since
the heat generated by the amplifier is considerable. The ventilation precautions
for fixed-station use also apply when operating mobile. In addition, a reason-
able amount of air flow must be provided around the inverter. Connections for
mobile operation are given in Fig. 3. Detailed installation instructions for
the SB3-DCP inverter are provided with the unit.
High-power mobile operation, particularly on the lower frequencies, has pre-
sented an antenna problem for many years due to corona discharge and exces-
sive loss due to loading-coil heat. These problems have been solved in the
"Webster KW Top Sider Series'' mobile antenna and its use with the SB2-LA
linear amplifier is highly recommended. Do not attempt to operate with con-
ventional mobile antennas; the high power generated will almost certainly
damage the antenna or completely destroy it. In some cases, a normal whip
antenna may be operated on 20 and 15 meters provided that a plastic top cap
is installed to suppress corona, but no conventional centerloaded mobile an-
tenna will withstand the power generated by the SB2-LA.
III. TUNING AND OPERATING PROCEDURE
Power to the amplifier is controlled by the FIL and POWER toggle switches,
Turn
the
fil
switch
to
ON
position.
The
amber
indicator
lamp
should
glow.
Wait
thirty
seconds
for
the
tubes
to
reach
operating
temperature.
Then
set
the
power
switch
to
HI
position.
The
power
circuits
of
the
amplifier
are
now
ready
for
tune-up
and
operation.
The
two
switches
are
electrically
inter-
locked so that power cannot be turned on until the tube heaters have been actu-
ated. In addition, the amplifier cannot be controlled from the transceiver