TB 9-6625-1998-35
8. Output Voltage
a. Performance Check
(1) Connect resistance standard (adjusted to 1000Ω) to OUTPUT. Connect audio
analyzer INPUT to resistance standard.
(2) Adjust OUTPUT CONTROL until OUTPUT RMS (VOLTS RMS) meter
indicates 1.0. If audio analyzer does not indicate between 9.5 and 10.5 V ac, perform b
below.
NOTE
Perform (3) through (6) below for AN/URM-127A only.
(3) Temporarily disconnect resistance standard from equipment setup by removing
cables from resistance standard.
(4) Set 1 kΩ LOAD switch to IN.
(5) Adjust OUTPUT CONTROL until TI VOLTS RMS meter indicates 1.0. Audio
analyzer will indicate between 9.5 and 10.5 V ac.
(6) Set 1 kΩ LOAD switch to OUT and reconnect cables to resistance standard.
(7) Repeat technique of (2) above at ATTENUATOR switch and meter indications
listed in table 3. If audio analyzer does not indicate within limits specified, perform b
below.
(8) Adjust OUTPUT CONTROL for 1.00 mV ac indication on audio analyzer.
(9) Substitute SWR meter for audio analyzer.
Table 3. Output Voltage
Test instrument
Audio analyzer indications
Meter
indications
ATTENUATOR
OUTPUT RMS
Min
Max
switch positions
(VOLTS RMS)
X10
V
.8
7.5
V ac
8.5
V ac
X10
V
.6
5.5
V ac
6.5
V ac
X10
V
.4
3.5
V ac
4.5
V ac
X1
V
1.0
0.95
Vac
1.05
V ac
X.1
V
1.0
95.0
mV ac
105.0
mV ac
X.01
V
1.0
9.50
mV ac
10.50
mV ac
1.0
0.95
mV ac
1.05
mV ac
V
X1000
5
