HP 400D - Auxiliary Equipment

TM 11-6625-1514-15
SECTION X
AUXILIARY EQUIPMENT
10-1. General
400-series Vacuum Tube Voltmeters, or similar
10-2. Auxiliary equipment extends the opera-
equipment, for carrier currents or other meas-
tion of the basic equipment, is not part of the
urements between 5 Kc to 600 Kc. With a
basic equipment, and is not required for normal
Model 200CD it provides fully balanced 135-
operation.
or 600-ohm output with attenuator in use.
With an H–P Model 400 it provides voltage
10-3. Line Matching Transformer Model
measurements on either 135- or 600-ohm bal-
11004A
anced line without grounding one side, and
permits bridging or terminated voltage meas-
10-4. The Hewlett-Packard Line Matching
urements on both 135- and 600-ohm lines. The
Transformer Model 11004A is specifically de-
Model 11004A Line Matching Transformer is
signed to connect a balanced system to H-P
shown in Figure 10-1. Specifications are given
Model 200-series Audio Oscillators, H-P Model
in table 10-1.
Table 10-1. Specification
Frequency Range: 6 Kc to 600 Kc.
Impedance:
Primary:
135 ohms ±10% or 600 ohms ±10%*
balanced line.
Secondary: 600 ohms, unbalanced line
Terminating Resistance:
(secondary of transformer)
600 ohms or 10,000 ohms.
Insertion Loss: Less than 0.3 db at 100 Kc.
Frequency Response:
Less than ±.5 db variation at
5 Kc and 600 Kc midfrequency value.
Balance: Better than 40 db over entire frequency
range.
Power Handling Capacity: +22 dbm (10 volts across
600 ohms).
Dimensions: 2 inches wide, 2 inches long, and 4 inches
high.
Weight: 12 oz.
10-6. The Model 11004A is used to terminate
a 600-ohm unbalanced line to a 135- or 600-ohm
balanced line. A two-position toggle switch,
the 600
Ω -BRIDGING switch, provides termi-
nating or bridging voltage measurement capa-
bilities for 135- and 600-ohm lines.
Measurements can be made in dbm directly
for either 135 or 600
Ω connections provided
the line is terminated. However, accurate volt-
age measurement can be read directly for the
600
Ω connection only. A schematic diagram of
the Model 11004A is shown in Figure 10-2.
The following rules will be helpful when de-
termining the position of the 600
Ω -BRIDGING
switch for various applications:
AGO 7945A
a. Use the BRIDGING position of the switch
(10K position) when bridging a balanced sys-
tem for measurement with an unbalanced line.
b. Use the BRIDGING position (10K posi-
tion) when driving a 600
Ω balanced system
with a single ended oscillator which has a 600-
ohm output impedance.
c. Use the 600
Ω position of the switch when
terminating a balanced line into single ended
measuring instruments.
Note. When connecting the Model 11004A into a
system, the ground post (G) should be connected to
the grounded side of the measuring equipment.
10-6. The Model 11004A is designed to in-
crease the usefulness of the H-P Models
10-1