Mega down imaging beam coverage

[mirons988]

Does anyone know what the width of the beam is, in relation to the depth, for the mega down imaging that is built into the SI units transducer. I'm just curious I haven't seen it posted anywhere.

[pfisher]

I think there is a picture in the owners manual showing the beam width in degrees. Then some of that high school math is involved :-)


In 455 I always figure 1.5 times the depth for the non-mega di.

[bobcoy]

• Down Imaging: 45° at 1.2 MHz, 75° at 455 kH. I don't do math! Bob
• OK i did calculation(Be skeptical) 45° =.8 X depth and 75° = 1.5 X depth

[mirons988]

Thanks for the info. Just what I wanted.

[pfisher]

• Down Imaging: 45° at 1.2 MHz, 75° at 455 kH. I don't do math! Bob
• OK i did calculation(Be skeptical) 45° =.8 X depth and 75° = 1.5 X depth

LOL

[skid00skid00]

But it isn't a 'cone'. It's more like holding a water balloon by the stem. You can google for images.
http://www.vexilar.com/blog/2014/08/...cer-beam-angle

Or other shapes:
http://www.raymarine.com/view/?id=197

[Wayne P.]

An Imaging pulse is very thin (like inches) from front to back, and wide to the sides. Think CAT scan.

[Bob B]

But it isn't a 'cone'. It's more like holding a water balloon by the stem. You can google for images.
http://www.vexilar.com/blog/2014/08/...cer-beam-angle

Or other shapes:
http://www.raymarine.com/view/?id=197

Those are 2D representations, not DI. The DI beam is very thin front to back and the beam angle others have indicated is side to side angle.

[skid00skid00]

Thanks for the clarification, guys. I was thinking 2D.
If I was feeling argumentative, I'd point out that the sound energy STILL isn't straight-edged like we may imagine, but I'm tired... :D