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try having their transducers set at different levels, switching to narrow cone angles, and
reducing gain or sensitivity settings.
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Cone Angle
To switch between a 20 degree and 8 degree cone angle, simply select CONE ANGLE,
and then change to your preferred cone angle. A feature unique to all Marcum Digital
Sonars is the “Sonar Footprint” that displays the actual area being covered by your
transducer while you are fishing. This data is displayed near the top of the screen, and
represents the diameter of the base of the transducer cone. This will keep you
constantly updated how much area is being covered by your RT-9, and will help you
decide which transducer angle best suits the conditions. When first turned on, it will be
transmitting utilizing the 20-degree setting.
Conditions where the narrow beam (8 degree cone) will benefit you are:
1 — fishing in deep water (over 40’)
2 — fishing along very steep drop-offs for bottom-hugging walleyes
3 — fishing in big schools of fish, like suspended crappies
4 — fishing in and around heavy weeds or standing timber
5 — when fishing in a crowd, the narrow beam will reduce interference
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Target Adjust
This feature allows the angler to change the size of the signals being displayed without
increasing the sensitivity. The TARGET ENHANCE feature will give you the smallest signal
size at “0”, and the signals displayed will get thicker as you increase the TARGET
ENHANCE. This feature should be used in conjunction with the sensitivity to fine-tune
your display. Those who have a hard time seeing, as well as those who fish from a
standing position will really appreciate the “TARGET ENHANCE” feature
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Bottom Enhance
This feature allows you to enhance your bottom reading to distinguish between a
potential target and the bottom.
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Color Palette
The six color palette is the RT-9 default, but there are other options to experiment with.
If you experience excessive clutter, switching to a three-color palette may clear it up.
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Ping Rate
Allows for controlling the pulse rate of the transducer. Default is “4”, in shallow water
you may find lowering the ping rate improves performance.
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Scroll Speed
The larger the number, the faster your signals will move across the screen in Chart
Mode. Slowing the speed down allows you to see the “history” for longer.
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Transducer Offset
Use this to offset the distance your transducer is below the water line to get a true
depth reading. If the transducer is a half-foot below the water line, setting the
