TM 11-6625-828-45
the connector to the panel. Tighten the four screws.
(7) On the front panel, replace the 51-ohm
(5) On the front panel, replace the
cap on 1 VOLT connector J105.
ATTENUATOR UV control dial and tighten the
setscrews.
3-6. Lubrication
(6) Reconnect RF cable (fig. 3-1) connector
P102 to connector J103 (fig. 3-6).
Lubricate the RF attenuator rack and spur gear assembly
as shown in figure 3-7.
SECTION II. ALIGNMENT
3-7. Test Equipment Required for Alignment
The chart below lists test equipment required in aligning
Test Set, Radio AN/ARM-5A, the associated technical
manuals, and assigned common names.
Test equipment
Technical manual
Common name
Multimeter TS-352BU ...........................................T6625-366-15................................................ Multimeter
Electronic Voltmeter ANIU RM-145 ......................T6625-524-14 and TM 11-6625-524-15-1 .... Electronic voltmeter
Filter Unit (Aircraft Radio Corp. Model F-12) ....... ...................................................................... Filter unit
Voltmeter Electronic ME30E/U .............................T6625-320-12................................................ Vacuum tube voltmeter
Resistance Bridge ZM-4U .................................... ...................................................................... Decade resistance box
Test Set, Signal Generator AN/GSM-21 ..............T6625-609-14................................................ Course checker
Signal generator
Audio Signal Generator (Collins Radio Model 479S-3)
Oscilloscope AN/USM-281A ................................T6625-1703-15.............................................. Oscilloscope
generating variable phase 39, 90, and 150 cps signals
3-8.
Characteristics of Test Equipment Required
for checking VOR equipment is required.
for Alignment
The type of test equipment required for alignment of the
3-9. %M and RF Meter Zero Alignment
AN/ARM-5A is listed below.
a. Multimeter.
a. Initial Adjustment. The test set %M and RF
volt volt-ohm-meter, capable of measuring dc voltage at
meters are initially adjusted for electrical zero by means
2.5 to 500 volts.
of the ZERO SET knobs located immediately below each
meter.
b. Connections and Settings. Connect the 51-ohm
input impedance of 1 megaohm is required to measure
termination cap to the RF OUTPUT-1 VOLT connector,
dc voltages from 5 to 50 volts with an accuracy of 1
and set the front panel controls and switches as
percent.
b. Electronic Voltmeter. A voltmeter capable of
indicated in the chart below.
measuring a signal of 30,u V at 100 to 150 me to an
Control on switch
Setting
accuracy of 5 percent.
c. Vacuum Tube Voltmeter. A voltmeter capable of
POWER-STANDBY
POWER
accurately measuring levels from 100 mv to 1 volt in the
30 - MOD
Fully counterclockwise
range from 30 Hz to 20 kHz should be used.
90 - MOD
Fully counterclockwise
d. Decade Resistance Boxes.
Three decade
9960 - MOD
Fully counterclockwise
resistance boxes should be available, each with a
150 - MOD
Fully counterclockwise
resistance range of 1 kilohm to 1.2 megohms.
RF LEVEL SET
Fully counterclockwise
e. Standard Course Checker. A standard course
1000 - MOD
Fully counterclockwise
MODULATION
30 -
checker capable of measuring the demodulated OMNI
IDENTIFIER
OFF
track angle to an accuracy of 0.1 should be used.
MC switch
A
ATTENUATOR V
Midscale
c. RF Meter Zero Alignment. Push in the ZERO
SET control and adjust the control to align the meter
needle with the ZERO SET line on the meter scale.
d. %M Meter Zero Alignment. Push in the
Change 1 3-11
