PULSE 12 DESCRIPTION
The PULSE 12 is a boat-towed pulse detector consisting of an 24"
by 36" Coil, a towable Fish (removable for land use), a Pre-amp, a
150/300' Cable, and a Control Box. The Control Box can support
one, two, or three Fish; all being towed at the same time. If you
purchased a single Fish, you can add additional Fish at any time.
Figure 2
For underwater use, the Coil is mounted on the Fish and is towed
at any depth down to 150/300 ft. The Fish sails through the water at
a depth determined by the speed of the boat and the amount of
cable let out. The dynamics of the Fish is that it tows very flat and
directly below the boat ( see Figure 3a ). As more cable is let out, or
the speed of the boat increases, the Fish tows further behind the
boat. An increase in boat speed results in reduced fish depth. If
towing in deep water, a downrigger ( 25# of lead ) can be added to
the line to insure maximum depth for the Fish ( see Figure 8b ).
For pinpointing, or for very small search areas, the coil can be
disconnected from the fish and suspended over the side of the boat.
A simple three point harness, made out of rope, insures that the coil
remains flat ( see Figure 3b ).
2
Control box
150/300' cable
Pre-amp
Coil
Fish
Figure 3b
Cable to
boat
Figure 3a
Cable to
boat
If only one towfish is being used, the readings for Fish 2 and Fish
3 will be approximately 150mv.
If a GPS or Loran C is not being used, or if the GPS or Loran C
message is not being properly received by the Pulse 12 the
message will be as follows:
@ NO POSITION AVAILABLE, Fish 1=,3270,Fish 2=,1650,
Fish 3=,350<cr><lf>
When using the Pulse 12 with a Loran C or GPS receiver the
following connection and power-up sequence must be followed for
proper operation.
1. Cable up entire system including GPS/Loran C to Pulse
12, Pulse 12 to the computer (RS232 interface), and
Pulse 12 towfish to Pulse 12 control box. Also connect
all components to their proper power sources.
2. Power-up GPS/Loran C and obtain current position fix.
3. Power-up computer.
4. Power-up Pulse 12
5. Initiate data collection program on computer.
If the Pulse 12 is powered up before the GPS has obtained the
current position or the GPS interface cable is disconnected, the
RS232 interface will default to the "No Position Available" message
s shown above.
If the GPS/Loran C loses its position fix during operation, the Pulse
12 will default to the "No Position Available" message".
If either of these conditions occur correct the fault (re-initialize the
GPS, check connections, check battery condition). Once the GPS/
Loran C is again functioning properly, power down the Pulse 12,
wait five seconds and power up the Pulse 12. The position
information should now be present.
11
Red
