Edgetech 3200-XS, User Manual

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B-1
APPENDIX B: Frequently Asked Questions
Below are some frequently asked questions about the 3200-XS Sub-Bottom Profiling
System. They encompass most of the questions asked by EdgeTech customers; however,
should other questions arise, please contact EdgeTech directly. For contact information
refer to “Customer Service” on page x.
1.
What are the tow vehicle tow cable requirements?
The tow cable must include three shielded twisted wire pairs. One set must be
18-gauge wire and is used for the transmitted signal. The other two sets must be
20-gauge wire and are used for the received signal, 12 VDC, common, and a spare.
2.
Can a Rochester 301301 (3 core coax) armored cable be used?
A 500-meter maximum length armored cable can be used. Contact EdgeTech for the
wiring recommendation.
3.
Can you interface a 3200-XS Sub-Bottom Profiling System to a transmit/receive hull
mounted array that is customer supplied?
This can be done; however, special engineering and calibration is required for
optimum results. EdgeTech can provide these services. Basically, the output
impedance of the Power Amplifier in the Deck Unit must match the input impedance of
the transducer array. This match will maximize the power to the transducers, otherwise
power will be lost in the amplifier instead of being output to the transducers. Matching
is done with a transformer with the correct turns ratio. In addition, a hydrophone has to
be temporarily placed below the transmitting transducers so that the system can be
calibrated. Based on the calibration information, the system can be tuned in such a
manner as to flatten the spectrum to improve the resolution of the records.
4.
How long a tow cable can I use?
Up to a 500-meter factory approved tow cable can be used.
5.
How close to the bottom do I need to tow?
Unlike side scan sonar, it is not always necessary to tow the tow vehicle near the sea
floor to get good results. Depending on which tow vehicle is used, it is possible to get
good results with hundreds of meters of water column. Towing the tow vehicle close to
the bottom reduces the area of the sea floor insonified and therefore reduces the
scattering. A focused, narrow beam also produces better spatial resolution.