My Beam Angle is wider than yours!
C.H. Smith Marine
Boat Equipment & Supplies, Marine Equipment
A transducer’s beam angle depends on a number of factors. The size and type of element, the configuration of the elements and the operating frequency.
The physical shape of an element will change the size and shape of the beam that is transmitted. Disc shaped elements typically produce a conical beam, whereas a bar element will create a fan shaped beam
Element configuration will alter the beam angle, on higher quality transducers, “clusters” of elements are used.
Frequency (which is actually set due to element construction and dimensions) influences the beam shape, the lower the frequency, typically the wider the beam width.
Beam spread is largely determined by the frequency and diameter of the transducer. Beam spread is greater when using a low frequency transducer than when using a high frequency transducer. As the diameter of the transducer increases, the beam spread will be reduced.
The transducer concentrates the transmitted sound into a beam. In theory, the emitted pulse radiates out like a cone, widening as it travels deeper. In reality, beam shapes vary with the transducer type and typically exhibit "side lobe" patterns.
The signal is strongest along the centreline of the cone and gradually diminishes as you move away from the centre. Wider angles offer a larger view of the bottom, yet sacrifice resolution, since it spreads out the transmitter's power. The narrower cone concentrates the transmitter's power into a smaller viewable area.
The so called "boomerang" look of individual fish on a screen is influenced by the beam angle. Quite often only half a boomerang appears on the screen. This could be for a number of reasons:
the fish was on one side of the boat only
a narrow beam angle was being transmitted
So if you were using 200khz you could try switching to 83 khz on a Lowrance transducer for example.
Now you can check the beam angle of your transducer and see more fish more often!
To sum up, a wide cone angle can detect fish around the boat and not just those directly under it, while exhibiting less target separation. A narrow cone concentrates the sound output enabling it to better detect small details, such as fish or bottom structure, but only scans a small amount of water at a time.
Boat Equipment & Supplies
, Marine Equipment