TB 9-4920-454-24
10. % RPM Indicator
a. Performance Check
(1) Set RPM switch to CAL 100% RPM and adjust RPM CAL ADJ control for
100.0 indication on % RPM indicator.
(2) Set RPM switch to N1.
(3) Short pins A and B on RPM INSTRUMENT CABLE receptacle, using test
probe hooks.
(4) If % RPM indicator does not indicate .0 or .1, perform b (1) through (3) below.
(5) Set RPM switch to N2.
(6) Remove shorting connection from pin A, and connect to pin C on RPM INPUT
INSTRUMENT CABLE receptacle.
(7) %RPM indicator will indicate .0 or .1.
(8) Remove short from pins B and C and connect equipment as shown in figure 5.
TEST INSTRUMENT
CALIBRATOR
WIDEBAND
A
D
C
B
RPM INPUT
INSTRUMENT CABLE
CONNECTOR
Figure 5. % RPM indicator.
(9) Set RPM switch to N1.
(10) Set calibrator for a 20 mV, 70 Hz wideband output.
NOTE
It may be necessary to temporarily disconnect TI to eliminate
clock interference in (10) above.
