Exciter Requirements; Transmitting Agc; Vox Relay - DRAKE L-4B Instruction Manual

rear of the L-4B chassis for this purpose.
It Is always a good idea to connect the chassis' of-all associated equipment to ­
gether and ground them at one point to avoid ground loops. We recommend that
all of the equipment in
your
station be connected together and grounded at the L-48
amplifier chassis.
I. EXCITER REoUIREMENTS
To operate the L-48 at the maximum legallnput, it will be required of the exciter
to deliver to the L-48 input connector, 100 watts PEP-SSB RP power and 15 watts
RP power on CW, AM RrTYand TUNE. The TR-3, TR-4. r-4/r-4X/l'-4XB Trans ­
mitters all have adequate power to drive the L-4B
to
the maximum legal input
allowed on 8SB, CW.
Rl'T~
and
AM.
The exciter should be placed as close to the
L-48 amplifier as practical so that the coax and ground strap will
be
short.
J•
TRANSMITTING AGe
A jack on the rear of the L-48 amplifier is
proVided
for connection to the exciter
of
a
transmitting AGe voltage which controls the gain
of the exciter so that
any
power level can
be
run up to 2000 watts PEP without peak clipping•.The L-48 is
supplied with a cable
to
connect this jack to a similar jack on our Model AC-4
Power Supply which terminates in the particular transmitter the AC-4 is powering.
A connector is available for AC-3 Power Supplies
that
brings out the vox c·ontacts
and a transmitting AGe connector from the transmitter that the AC-3 is powering.
K. VOX RElAY
A two pin
Jack on the rear of the L-48 amplifier Is prOVided for connection to a
pair of nonnally open relay contacts in the exciter which close on transmit and
thus tum on the L-4B at the same time. The L-4B is supplied with a cable to
connect this Jack to a similar Jack on our Model
AC-4
Power Supply which termin­
ates
in the particular transmitter the
AC-4 is powering.
Some exciters (except TR-3, TR-4. T-4/r-4X/1':"4XB) ground one of the
extra
relay
contacts made available to key a linear amplifier. For these exciters it will
be
necessary to plug the two pin connector tnto the L-48 vox socket in the correct
. position. With the exciter 1n
standby, if
plugging
in the
vox
connector
causes
the L-48 plate current to read up scale, reverse the vox connector 1n its socket so
that the"
L-48
plate current Is zero.
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