Humminbird Side Imaging Forums

Side Imaging Forums => Helix Series Units => Topic started by: Tatersalad on March 06, 2018, 06:23:55 PM

Title: Helix 10 SI G1 downscan width
Post by: Tatersalad on March 06, 2018, 06:23:55 PM

I recently purchased a Helix 10 si G1 and I've only had it out on the water once but I'm very impressed. I do have a question, the online operator manual says you can select down imaging width (wide, med and narrow) But I can not find that option on my unit. Is this something that was dropped in later production side image units?

Tater

Title: Re: Helix 10 SI G1 downscan width
Post by: rnvinc on March 07, 2018, 08:10:27 AM

The DI Width selection is under the Sonar tab  ... (Make sure User Mode under Setup tab is set to Advanced)  ...

DI Width is available in HB SI units that do not have a dedicated DI piezo in the SI xducer - which would include all SI units except ONIX, ION, SOLIX and HELIX MEGA units  ...

Rickie

Title: Re: Helix 10 SI G1 downscan width
Post by: Tatersalad on March 07, 2018, 11:12:37 AM

Thanks, you know after running Humminbirds for years (currently my 4th unit) I should of remembered the advanced settings option. Must be old age the more I look for something the more I forget.
Again thanks
Tater

Title: Re: Helix 10 SI G1 downscan width
Post by: October1 on March 07, 2018, 05:34:21 PM

Quote from: rnvinc on March 07, 2018, 08:10:27 AM

The DI Width selection is under the Sonar tab  ... (Make sure User Mode under Setup tab is set to Advanced)  ...

DI Width is available in HB SI units that do not have a dedicated DI piezo in the SI xducer - which would include all SI units except ONIX, ION, SOLIX and HELIX MEGA units  ...

Rickie

So if I get a Helix 7 SI G2 the xducer doesn't have a dedicated DI crystal? It uses the SI to create a DI image? What if I upgrade to the HD ducer?

Title: Re: Helix 10 SI G1 downscan width
Post by: rnvinc on March 08, 2018, 08:24:32 AM

Quote from: October1 on March 07, 2018, 05:34:21 PM

So if I get a Helix 7 SI G2 the xducer doesn't have a dedicated DI crystal? It uses the SI to create a DI image? What if I upgrade to the HD ducer?

Correct  ... The only HELIX SI units that have SI and also have dedicated DI are the MEGA 9, 10, and 12 SI units ...

Upgrading the HELIX 7 SI unit's stock XNT 9 SI 180 T  to the upgraded XHS 9 HDSI 180 T will gain somewhat better SI imaging = because of the longer SI piezoes  ...

Upgrading to the XHS 9 HDSI 180 T will not make available the 800kHz frequency capability of the XHS 9 HDSI 180 T  ...

And upgrading will not add dedicated DI capability  ...

Rickie

Title: Re: Helix 10 SI G1 downscan width
Post by: October1 on March 08, 2018, 03:01:46 PM

Thanks Rickie.

This is a bit of a surprise and a disappointment. I thought Garmin was the only one that didn't use a dedicated crystal. I'm not sure why I was thinking that. Surely I must have come across this before and simply forgot about it. I wonder how the Helix 7 DI compares to a unit with a dedicated crystal.

It sounds like my dads 899 SI is probably the same way as well.

Title: Re: Helix 10 SI G1 downscan width
Post by: rnvinc on March 09, 2018, 08:49:17 PM

A little history  ...

*HB released SI in 2005  ...
*Lowrance released Sidescan and DownScan in ~Dec 2009  ...
*HB released Blended DI in a software update for SI units in ~Mar 2010 (to counter Lowrance DownScan) 
*HB released dedicated DI units in ~Sept 2010 (SI units continue blended DI in SI units)  ...

It is my guess that HB already has dedicated DI units in R&D and decided not to add dedicated DI in SI units because of the impending release of dedicated DI units just 6 months away  ...

ONIX was the 1st HB unit released with SI and dedicated DI in the same xducer  ... And now add to that list the MEGA SI units and SOLIX  ...

And the dedicated DI units are still a staple in the HB lineup in core series  ...

Rickie

Title: Re: Helix 10 SI G1 downscan width
Post by: October1 on March 09, 2018, 09:26:58 PM

Thanks for the added info Rickie. Have you seen the difference between the DI picture from blended SI units compared to the units with dedicated DI crystals?

I'm wondering if it's a significant difference or hardly noticeable? I don't want to get a Helix 7 if the DI is low quality and isn't very useful.

Title: Re: Helix 10 SI G1 downscan width
Post by: rnvinc on March 10, 2018, 10:08:56 AM

Quote from: October1 on March 09, 2018, 09:26:58 PM

Thanks for the added info Rickie. Have you seen the difference between the DI picture from blended SI units compared to the units with dedicated DI crystals?

I'm wondering if it's a significant difference or hardly noticeable? I don't want to get a Helix 7 if the DI is low quality and isn't very useful.

Imagine aiming 2 flashlights out to your sides (to represent SI beams) = your shoes will be illuminated - but not very bright-ly  ...

Now imagine aiming 1 flashlight directly straight down (to represent a DI Beam) = your shoes will be illuminated very well  ...

If the flashlights (in the SI analogy) are close to your close (shallow water) = your shoes would still be fairly well illuminated  ...

If the flashlights (in the SI analogy) are farther away from your shoes = your shoes will be less illuminated the farther away the flashlights are from your shoes  ...
-----

So shallow water blended DI still has enough sound pulse to get reasonably good echoes from under the boat  ... but gets less effective as water depth increases  ...

Conversely dedicated DI will always have an advantage (at targets under the boat) because the strongest part of the DI beam is aimed straight down  ...

Rickie