TM 1-1520-238-10
3-72
Table 3-24.
AN/APN-209(V) Altimeter Control and Indicator Functions
Control/Indicator
Function
LO SET knob
Power control turned counterclockwise to OFF; clockwise to on.
LO SET bug
Sets altitude trip point of LO warning light.
HI SET bug
Sets altitude trip point of HI warning light.
HI SET knob
Pushing knob actuates BIT system to self-test altimeter.
Altitude pointer
Provides an analog indication of absolute altitude from zero to 1500 feet.
Digital readout
Provides a direct-reading four-digit indication of absolute from zero to 1500 feet.
LO warning light
Lights whenever dial pointer goes below L altitude bug setting.
HI warning light
Lights whenever dial pointer goes above H altitude bug setting.
OFF flag
Moves into view whenever altimeter loses track while power is applied.
3.18.3 Operation.
a. Starting Procedure.
1. LO SET knob – On.
2. LO set bug – Set to 80 feet.
3. HI set bug – Set to 800 feet.
b. Track Operation.
After about two minutes of
warmup, the altimeter will go into track mode with these
indications:
1. OFF flag – Not in view.
2. Altitude pointer – 0 to+5 feet.
3. Digital readout – 0 to +3 feet.
4. LO warning light – Will light.
5. HI warning light – Will be off.
c. Self Test. Press and hold HI SET Knob.
The al-
timeter will indicate a track condition as follows:
1. OFF flag – Not in view.
2. Altitude pointer – 1000 100 feet.
3. Digital readout – 1000 100 feet.
4. LO warning light – Will be off.
5. HI warning light – Will light.
6. HI SET knob – Release. The altimeter will return
to indications in step b, Track Operation.
3.18.4 Stopping Procedure.
1. LO SET knob – OFF.
