Benthos 865-A, Instructions For The Installation, Operation And Maintenance

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Model 865-A Deep Sea Acoustic Release/Transponder M-855-009
Benthos, Inc.
30
b. If dry nitrogen is not available, open the electronics tube and change the desiccant pack, (or
dry out the old one in a low temperature oven). The indicator turns pink if the desiccant is
saturated, blue if it is dry. Replace the desiccant pack on top of the blue capacitors and close
the electronics tube.
c.
Close the housing and tighten the nuts tight, i.e. approximately 15 foot/pounds.
STEP 5 - INSTALL NEW ANODE
a.
Install the anode as shown on Drawing B-855-81, "Anode Installation Instructions". Be sure
to use all the specified hardware.
STEP 6 - SYSTEM TEST
a.
Turn release to ON-ARMED. Listen for four pings.
NOTE : Pings on power-up only occur if unit was previously off for more than one or two
seconds.
b. Set the deck unit to the proper code and send a single transpond. Because the transmit and reply
are happening almost simultaneously, the reply lamp may not always light. However, by lightly
touching the transducer on the 865-A one can often feel the output pulse and thus verify that a
reply is occurring.
Remember: If the unit is left on for longer than the enable time, it will
stop replying.
c.
Set the deck unit to the proper code and send a RELEASE command. For best results, place
the DS-7000 transducer about six inches away from the 865-A transducer (see Figure 4-2).
NOTE : It is sometimes very difficult to get a command through in air. If you have trouble, do
not panic! This is normal, as the system is designed to operate in water where the sound paths
are more predictable. Simply move the transducers to slightly different positions - often as little
as one inch (1") is all that is necessary to make the difference. It may be helpful to line the test
area with foam rubber to dampen reverberations.
When a command is successfully received, note that the release pin will fully retract so that the
lever may swing free. At full retraction, the motor shuts off and the 865-A will automatically
transmit a burst of four pings.