Humminbird HDR 650 - Manual (Page 30)

2. Trial Installation
You will not be able to adjust the mounting after an inside the hull transducer is
installed. It is best, therefore, to perform a trial installation first that includes
running the boat at various speeds, in order to determine the best mounting area
before permanently mounting the transducer.
1. Plug the transducer into the depth sounder, then power up the depth
sounder. When the depth sounder detects a functioning transducer, it will
automatically enter Normal operating mode.
2. View the sonar signal at its best by holding the transducer over the side,
immersed in the water, so that it is pointing straight down over a known
flat bottom. Use the display to benchmark against the sonar signal that
will be detected once the transducer is placed in the hull.
3. Place the transducer body face down at the identified mounting location
inside the hull, with the pointed end towards the bow (see the illustrations
Positioning the Transducer and Preferred Mounting Area).
Preferred Mounting Area Positioning the Transducer
26 Inside the Hull Transducer Installation