Cessna 177 SERIES Service Manual page 304

16-102. TROUBLE SHOOTING (Cont.)
TROUBLE PROBABLE CAUSE REMEDY
*POWER LOW
Low battery voltage. 1. Set toggle switch to off.
2. Disconnect the battery-pack from the
transmitter and connect a Simpson 260
model voltmeter and measure voltage.
If the battery pack transmitters is 7.5
volts or less, the battery pack is below
specification.
Faulty transmitter. 3. If the battery-pack voltage meets the
specifications in step 2, the battery-pack
is O.K. If the battery is O.K., check the
transmitter as follows:
a. Reconnect battery pack to the trans-
mitter.
b. By means of E. F. Johnson 105-0303-
001 jackplugs and 3 inch maximum long
leads, connect a Simpson Model 1223
ammeter to the jack.
c. Set the toggle switch to AUTO and
observe the ammeter current drain. If
the current-drain is in the 15-25 ma
range, the transmitter or the co-axial
cable is faulty.
Faulty co-axial 4. Check co-axial antenna cable for high
antenna cable. resistance joints. If this is found to be
the case, the cable should be replaced.
*This test should be carried out with the co-axial cable provided with your unit.
16-40 Change 7