TM 11-6625-2629-14&P
Figure 3-1. Meter, Modulation ME-57A/U, controls, indicators, and connectors.
Section II. OPERATION UNDER USUAL CONDITIONS
CAUTION
to the range containing the input signal
frequency.
Insure that the DEVIATION RANGE
KC switch is in the 1000 TUNE position
proximate frequency of the expected signal; use
b e f o r e energizing the equipment or
the TUNING knob.
damage to the DEVIATION meter may
result .
3-4. Operating Procedure
3-3. Preliminary Starting Procedures and Initial
NOTE
Adjustments
If an abnormal indication is obtained
during the operating procedure, refer to
Before power is applied to the modulation meter,
the troubleshooting chart Table 4-3.
perform preliminary operations listed below.
Operate the equipment as follows:
u. Check the line voltage selector switch and be
a. Check the controls to be sure that they are
sure that it is set to the correct liner voltage. Be
set as required by the preliminary starting
sure that the proper fuses are in use. Use a 2-
procedure (para 3-3).
ampere fuse for 115-volt operation, and a 1.
b. Set the POWER switch to the ON position
ampere fuse for 230-volt operation.
b. Plug the modulation meter into the power.
and allow 30 minutes for warmup.
source.
c. Measure deviation from either side of the
c. Set the TUNE-FINE TUNE switch to the
resting frequency as follows:
TUNE position.
(1) Connect an unmodulated carrier to the
d. Set the DEVIATION RANGE KC switch to
INPUT connector of the modulation meter.
the 1000 TUNE range.
(2) Rotate the TUNING knob until the
e. Set the FREQUENCY RANGE MC switch
CARRIER SHIFT meter indicates zero.
3-2
