User manual

Table Of Contents
8.0 KHz, …, 1111 selects 15.0 KHz. To meet the power output specification of the transponder
the transmit frequency should only be changed within one of three frequency bands: 7.5 KHz -
8.5 KHz, 9.0 KHz - 11.0 KHz, or 11.5 KHz - 15.0 KHz. Switch 6 has no function in the
transponder's MMP implementation and should be left OPEN.
If a deck unit is unavailable, you can usually trigger a ping in the laboratory or on deck
by jingling a set of keys or banging a pair of wrenches together near the transducer to test that the
transponder is working. The two systems share a common electrical ground and two DIO signal
lines. One signal is a TT8v2 IRQ activated by the transponder to indicate when it has pinged.
The MMP logs these interrupts during a deployment, but not otherwise. The other signal is a
command from the TT8v2 to ping.
Transponder Transducer Assembly
The transponder’s transducer assembly is mounted on the top rib of the MMP frame,
behind the upper glass sphere. The transducer does not require any maintenance beyond rinsing
with fresh water after a deployment. The transducer assembly consists of a 316 stainless steel
plate and band clamp, an oil filled neoprene boot containing the transducer, and an exposed
silicon-bronze bolt. The transponder cable should be run through the holes in the top three ribs
and over the gap in the fourth rib created by the upper mounting clamp for the controller housing.
From this point run the cable under the left side of the frame post and through the large hole in
the bottom rib to the controller end cap. Excess cable can be loosely coiled in the volume above
the bottom rib.
The top faired end cap must be removed to gain access to the transducer. Such access is
seldom necessary and is not recommended unless some repair operation, such as replacement of
the upper glass sphere, makes it necessary. To remove the fairing, unscrew the flat-head nylon
bolts securing the edge of the end cap to the top rib.
IMPORTANT
Exercise caution once the end cap is released as the upper glass sphere is free to roll.
Controller Housing
The controller housing contains the MMP controller electronics, the main lithium battery
pack, the transponder electronics (if installed), and the alkaline transponder batteries.
Appendix E-2