TB 11-6625-247-35
SECTION IV
WARNING
HIGH VOLTAGE is used during the performance of this
fail to observe safety precautions.
4-1.
Frequency Meter
a. Performance Check
(1) Connect the output of audio oscillator (A1) and the input of counter (A3) across
the terminals of FREQUENCY METER of the Test Instrument, using radio frequency
cable assemblies (B6) and (B7), and connector adapter (B2).
(2) Adjust the audio oscillator frequency to 400 Hz, and the output amplitude until
reed vibration can be seen on FREQUENCY METER of the Test Instrument.
FREQUENCY METER under test. Counter (A3) shall indicate 1% of
frequency marked
on meter under test. Tests shall be performed at each division mark on meter under test.
NOTE
The Test Instrument may contain any of the following
frequency meters
1.
Frahm, Catalog No: 4997, range 380 to 420 Hz, 10
divisions, 4 Hz per division.
2.
Winslow, Model 459-3644, range 360 to 440 Hz, 8
divisions, 10 Hz per division.
3.
Winslow, Model 460, range 380 to 420 Hz, 8 divisions, 5
Hz per division.
4.
Frahm, no model indicated, range 360 to 440 Hz, 10
divisions, 8 Hz per division.
5.
Other manufacturer's models may be encountered.
b. Adjustments. No adjustments can be made.
5