Transducer Placed Forward...What is Seen?

[Bartableman7]

Standard GT20-TM transducer mounted so the beam goes outward from the front of the trolling motor...what images do I see as fish are sitting still or swimming across the beam? (Both traditional down scan and clear vue.)

[Choporoz]

If mounted correctly on your trolling motor, the transducer shoots pings straight down.  You see pixels that represent how far away the ping hit something and returned to the transducer.  The outgoing ping 'widens', so you are looking at a representation of an ever widening area as distance (depth) increases.  So any images are just your fishfinder trying to interpret those echoes for you

[casts_by_fly]

if you're trying to make a poor man's live scope it won't work.  The refresh rate and the power output will not provide a clear enough image.  

[MN Fisher]

Basically the same you'd see if mounted normally to shoot down. You'll get returns, but trying to identify them is problematic.

Also, the cone that standard 2D and the 'slice' that Clear Vue (Garmin's Downscan) gives you won't help place the fish as they could be anywhere in the 'field of view'.

[Choporoz]

21 minutes ago, casts_by_fly said:

if you're trying to make a poor man's live scope it won't work.  The refresh rate and the power output will not provide a clear enough image.  

Ok....I see....I didn't understand the question 

[Bartableman7]

48 minutes ago, MN Fisher said:

Basically the same you'd see if mounted normally to shoot down. You'll get returns, but trying to identify them is problematic.

Also, the cone that standard 2D and the 'slice' that Clear Vue (Garmin's Downscan) gives you won't help place the fish as they could be anywhere in the 'field of view'.

This is a great image.  So why have a rectangular transducer to produce a circular beam for 2-D?  Does it use only a portion of the transducer to get a round pattern?

 

[MN Fisher]

1 minute ago, Bartableman7 said:

This is a great image.  So why have a rectangular transducer to produce a circular beam for 2-D?  Does it use only a portion of the transducer to get a round pattern?

 

The actual electronic portion that sends/receives the signal is round - the rectangle case includes other components that convert the sound waves (sonar signal is sound) into electrical signals that are send down the wires.

[casts_by_fly]

27 minutes ago, Bartableman7 said:

This is a great image.  So why have a rectangular transducer to produce a circular beam for 2-D?  Does it use only a portion of the transducer to get a round pattern?

 

 

Also, as you're looking at that picture, think about it like a flashlight.  Hooked the back of the boat, the 2D is the full round beam.  If you tilted it forward, it would be like you were walking along a path and what hits the ground now becomes an ellipse, not a circle.  The bottom depth will be shallower (closer) at the front of the ellipse on the ground and deeper (further) on the far end.  If you tilted it at a steeper angle the front of the beam would hit the bottom for hundreds of feet.  The head unit is programmed to translate the returns from the bottom based on a circle and known geometry.

 

Same applies for the downscan, except its a narrow strip of light and not a full round beam.

[TnRiver46]

I’ve done this before, it’s a wild ride haha. It will still mark fish but you don’t really know where they are. Definitely set the range to how far you want to see if you try it, otherwise it will go 500 feet or more until it hits something 

 

it still can be a poor man’s FFS if you set it to flasher mode but it sure isn’t going to be crisp and clear like the live units now . More like ice fishing sideways 

[Tennessee Boy]

If you point the transducer forward at 45 degrees it would look similar to what you see when it’s pointed straight down over a 45 degree sloped bottom.  There’s a lot of places for fish to hide from view in both situations.