Teleflex TFXIDF Operation Manual page 7

feet. You can determine a hard bottom because of the strength of the return
(clear, black signal). A second echo would normally appear at 36 feet.
However, the IDF unit has a feature to prevent wrap on all scales to assist in
the sound waves and thus return a weak signal. Adjust the sensitivity level for
a better bottom signal.
USING THE IDF SERIES
Hard Bottom: The illustration at the bottom of
the previous page identifies a hard bottom at 18
differentiating bottom, second echo and fish.
SUPPRESSION
IDF
the
SIGNAL INTERPRETATION
15'
20'
A hard bottom starting at 20' with a
smaller fish giving a weak return at 15'.
Hard bottom at 18'
Soft bottom about 18'
Soft Bottom: A soft bottom is displayed on
as a gray return. Soft bottoms absorb
5'
10'
5