TM 11-6625-2398-15-3
(7)
Fixed Attenuators AT1/AT2(2).
8-7.
Hybrid Attenuator Insertion Loss Measurement
between RF IN/OUT and ATTEN IN/RF DIFF
(8)
Termination AT3/AT4(1).
Connectors
(9)
50-ohm
Terminations
(2),
Microlab/FXR
a. Test Equipment and Materials.
TA-6MN.
(1) Signal Generator SG-340/G.
(10) Cables W14/W15(2).
(2) Variable
Attenuator,
Alfred
Electronics
(11) Cable A1W3.
Model E101.
(12) Adapter UG-606/U.
(3)
Standing Wave Ratio Indicator AN/UPM-
108A.
b. Test Connections and Conditions.
Initially
(4)
Crystal Detector HP-423A.
connect the equipment as shown in solid lines, figure 8-4.
Disconnect the hybrid attenuator and connect the variable
(5)
Adapter UG-201A/U.
attenuator (connections shown in broken lines) as-directed
(6)
Adapters CP7/CP8 (2).
in the procedure below.
Step
Test equipment
Equipment under
Test
Performance
No.
control setting
test control settings
procedure
standard
1
a. SG-340/G
None
a. Set the MEGACYCLES dial to
POWER: ON
1030 with the frequency control
Function Switch:
knob. Turn on the signal generator
CW
and allow a minimum of 20 minutes
MEGACYCLE:
warm-up period before proceeding.
1030
b. AN/UPM-108A
b. Turn on the standing wave ratio
Power ON
indicator and allow a minimum of
METER SCALE:
10 minutes warm-up period before
NORMAL
proceeding.
INPUT SELECTOR:
XTAL-200 K 1
c. SG-340/G
POWER: OFF
zero set the OUTPUT VOLTS
(down)
meter.
OUTPUT VOLTS:
zero set
d. SG-340/G
POWER: ON
adjust the OUTPUT LEVEL. con-
Attenuator 0dB
trol knob for an OUTPUT VOLTS
OUTPUT VOLTS:
meter indication at the SET LEVEL.
SET LEVEL
(+4DBM), mark.
Note. Check that OUTPUT VOLTS meter
indication is exactly on the SET LEVEL mark.
with the attenuator set to 0dB 4 (outer scale)
Readjust the OUTPUT LEVEL control knob
if required.
2
SG-340/G
ATTENUATOR: 0
Adjust the MOD LEVEL control for
Function Switch:
(zero)
a reading of 50 on the PERCENT
MODULATION meter. Adjust the
1000
PERCENT
standing wave ratio indicator
MODULATION: 50
VERNIER GAIN control and
ATTENUATOR:
RANGE switch exactly on the SET
0 (zero)
LEVEL mark, with the attenuator
set to 0dB (outer sale). Readjust
the OUTPUT LEVEL control knob
if required.
2
SG-340/G
ATTENUATOR: 0
Adjust the MOD LEVEL control for
Function, Switch:
(zero)
a reading of 50 on the PERCENT
1000
MODULATION meter. Adjust the
8-14
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