is connected to two 0.150 ampere lamps
mounted inside the meter case.
The output level (deflection to the 0 vu or
100 mark) to be indicated by the meter is
set by means of the volume indicator range
switch to correspond to levels at the outgo
ing line of +4, +6, +8, +10. +12 and +14
vu. In most cases +8 vu is a satisfactory lev
el to feed a line. This range switch has an
OFF position, and a PLATE and FILA
MENT position for checking plate and fila
ment batteries. For the purpose of checking
battery voltages, the 0 vu or 100 mark on the
scale indicates the minimum operating volt
age. Checking may be done during program
without interfering with the operation of the
amplifier.
Monitorin9
Two monitoring jacks are provided on the
right hand end of the front panel of the am
plifier. These jacks are connected in parallel
and are intended to provide monitoring fa
cilities for the operator and a second person.
They are bridged across the output of the line
pad in use. As shown in the schematic dia
gram, Figure 3, an isolation resistor is in
cluded in the monitoring jack circuit to
isolate the program channel from an acci
dental short circuit. The jacks accommodate
Western Electric Type 47 or similar type
plugs.
When loudspeaker monitoring is desired,
or when sound reinforcement is required, a
Western Electric 124E or 142A Amplifier,
or equivalent, may be used. These amplifiers
have a high impedance input which can be
bridged directly across the line or plugged
into one of the headset monitoring jacks of
the 22E Amplifier.
A 47 Type Plug and a cord such as the
630 Type are recommended for making con
nections between the 22E Amplifier and the
monitoring amplifier.
ES-610199 Power Unit
For a-c operation, the ES-610199 Power
Unit provides all necessary power for fila
ment.<\ and plates. One type 80 rectifier tube
serves as the plate supply rectifier. The unit
contains a receptacle for the battery unit
cord and plug, and two switches so that the
filament and plate supplies may be obtained
from either batteries or the a-c supply. All
power connections to the Amplifier-Control
Unit are made with a single 6-foot, heavy
duty, five-conductor cable. A plug cap is f.ur
nished in the power unit socket for the pur
pose of connecting a length of rubber-covered
cordage from an a-c outlet. The cordage and
the male cap are not furnished as a part of
the unit.
B-147071 Set of Ac:c:essories for Battery
Operation
The B-147071 set of accessories is a kit
containing all the parts necessary to adapt
the lower compartment of the battery carry
ing case to accommodate a complete set of
batteries for battery operation. A length of
cable, connecting wires, hardware and com
plete instructions for installing the batteries
are included in the kit. Batteries are not fur
nished, and must be ordered separately if
required. A list of batteries required for op
eration is given in the section "Acce:<sories
Required".
INSTALLATION
In ordering, it is necessary to specify
whether the 22E Speech Input Equipment is
intended for a-c or for battery operation, or
for both, and which type volume indicator
meter is desired.
4
Equipment Furnished
For AC Operation
When a-c operation is specified, the equip
ment furnished consists of the following
basic components:
