TM 11-6625-2398-15-3
(8) Correct the hybrid attenuator calibration tag
Cables W14/W15(2).
marking for 1090MHz, if incorrect.
b. Procedure. Connect the equipment as shown in
solid lines (fig. 6-2) and proceed as follows:
NOTE
(1) On the signal generator, set the
This insertion loss must be slightly more (at
MEGACYCLES dial to 1090 with the frequency control
least 0.2dB) than the insertion loss measured
knob. Set the function switch to CW. and turn on the
between the RF IN/OUT and ATTEN IN/RF DIFF
signal generator. Allow a minimum of 20 minutes warm-
jacks (para 6-9).
up period before proceeding.
(9) Reconnect the hybrid attenuator, solid lines
(2) With the METER SCALE set to NORMAL, and
INPUT SELECTOR set to XTAL 200-KΩ, turn on the
SWR indicator and allow a minimum of 10 minutes
(10) Reset the signal generator MEGACYCLES
warm-up period before proceeding.
dial to 1030 and repeat steps (3) through (7) above.
(3) Turn on the signal generator and zero set the
(11) Correct the hybrid attenuator calibration tag
OUTPUT VOLTS meter.
marking for 1030MHz, if incorrect.
(4) Turn on the signal generator, and adjust their
6-9. Hybrid Attenuator Difference Channel (RF
OUTPUT LEVEL, control knob for an OUTPUT VOLTS
IN/OUT to ATTEN IN/RF DIFF Jacks) Insertion
meter indication at the SET LEVEL (+4DBM) mark, with
Loss Calibration
the attenuator set to 0dB.
NOTE
a. Test Equipment and Materials. The following test
equipment and materials are required:
Check that OUTPUT VOLTS meter indication is
exactly on the SET LEVEL mark with the
Signal Generator SG-340/G
attenuator set to 0dB (outer scale). Readjust
the OUTPUT LEVEL control knob if required.
Variable Attenuator, Alfred Electronics Model
E101
(5) On the signal generator, set the function switch
to 1000 ~ the MOD.
UP-NORMAL -DOWN to
SWR Indicator AN/UPM-108A
NORMAL, and adjust the MOD. LEVEL, control for a
reading of 50 on the PERCENT MODULATION meter.
Crystal Detector HP-423A
With the SWR indicator METER SCALE set to
EXPAND, adjust the SWR indicator VERNIER GAIN
Adapter UG-201A/U
control and RANGE switch for an exact meter reading
(e.g., 5 on the EXPANDED DB meter scale). Record
Adapter UG-606/U
the meter reading.
Adapter CP7/CP8 (2)
(6) Disconnect the hybrid attenuator under test
and connect the variable attenuator, as shown by the
Fixed Attenuators AT1/AT2 (2)
broken lines in figure 6-2.
Termination AT3/AT4
(7) Adjust the variable attenuator ATTENUATOR
DB control for the same SWR indicator meter reading
50-ohm Terminations (2), Microlab/FXR TA6MN
recorded in step b(5).
Insertion loss on the
ATTENUATOR DB control of the variable attenuator
Cables W14/W15 (2)
must indicate 6.5 1.5dB.
Cable A1W3.
b. Procedure. Connect the equipment as
6-7
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