ONLINE ELECTRONICS LTD
2405_5001_A01
Page 7 of 14
3.1.
SELF TEST
1.
Turn the 2405 ON as described in section 3.3 TURNING ON.
2.
Put the 2405 into TEST MODE as per section 3.4 OPERATING SCREEN.
3.
On entry to TEST MODE the unit sets the receiver frequency
to 30kHz, timebase to 5 seconds, and gain to AGC003.
4.
The unit then begins generating an internal 30kHz test signal
with a repetition rate of 1 second at the 2401 input.
5.
Because AGC gain is initially set to 003 (minimum setting) no signal will be seen however
the unit should detect this and start increasing the AGC gain until the pulses are
approximately ¾ of the way up the screen. This should take approximately 30 seconds.
The final AGC value should be over AGC70.
6.
Notice that because the timebase is 5 seconds and the internal test ping repeats every 1
second that 5 evenly spaced pulses should be visible on the screen and a 1SEC repetition
rate should also be detected at the bottom right hand side of the screen as shown.
7.
The 2405 will remain in TEST MODE for 4 minutes or until the operator manually enters
PINGER MODE.
8.
Note that any pre-configured frequency, timebase and gain settings entered prior to
entering TEST MODE will be saved.
3.2.
FUNCTION TEST
1.
Turn the 2405 ON as described in section 3.3 TURNING ON.
2.
Ensure the 2405 is in PINGER MODE with AGC gain as per section 3.4 OPERATING
SCREEN.
3.
Activate a test transmitter of known frequency and repetition rate within range of the 2401
hydrophone. A range of approximately 5cm should be used if in air.
4.
Set the frequency of the 2405 to the transmitter frequency.
5.
Confirm that the AGC gain adjusts until the pulses are approximately ¾ up the screen.
Adjust the timebase if necessary until approximately 5 pulses are present on the screen.
Confirm that the timebase and number of pulses on the screen reflect the expected
repetition rate. The LEDs should illuminate during each pulse and the correct repetition
rate should be displayed on the bottom right of the screen.
6.
If a test transmitter is not available then a crude signal can be generated by very gently
tapping the active face of the 2401 hydrophone with a finger. The signal should be visible
on the screen with the frequency of the 2405 set to 9kHz.
7.
Turn off any test transmitters and remove any local sources of obvious noise and/or
vibration. Because no signal is present the AGC should increase to AGC255. The noise
level displayed should be less than ¼ up the screen.
