Tipsey SI transducer questions

[cache22]

If you rotate SI transducer 60 degrees to see down image, does if make a difference if you just show the side you are using or should you show both sides? Also how does the water column show up if you don't have the 200 frequency pointed at the bottom and what happens if you set contour view???

[rnvinc]

1st it's important to understand that rotating the SI xducer 60° will not only "point" that SI piezo straight down ... It also "points" the opposite SI piezo toward the water's surface ...

This can cause some very un-natural and unsatisfactory images from that "upward-pointed" SI piezo reflecting off the water's surface ...

This issue can be eliminated by using the AS SIDB Y cable and removing the SI pin in the AS SIDB Y cable that connects the "upward-pointing" SI piezo ... (This is cheaper than removing a pin in a $270 HDSI xducer) ...

Using the AS SIDB Y cable is necessary anyway for the rotated SI xducer setup ...because the 2d piezo is no longer "pointing" down to get accurate depth readings ...

Another option for this Setup is a SI xducer that one side is not working anyway ...but the AS SIDB Y cable still needs to be used to get correct digital depth readings ...
----

Now with one of the SI piezoes disconnected (or not working)... The SI image will only show data on one side (the side with the still live SI piezo) ...

The opposing side of the SI image will be black (because no data is able to get thru the AS SIDB Y cable SI pin that was removed) ...

Furthermore ... Because the DI image (in the HB SI unit) is a composite of the left and right SI data ... The processor now blends the "good" data from the live SI piezo with the "no data" from the dead SI piezo ... To get a DI image comprised only from data received in the SI piezo that is now "pointed" straight down ...

So it doesn't really matter which side the SI is set to view ... The SI image is no longer SI data (from the side) ...

The SI image is now "down-pointing" data ... Plotted into one side of the SI image ...

And the DI image is no longer "DI from side-pointing piezoes".. The DI image is now DI from a piezo that is pointed straight down ...

Rickie

[cache22]

Thanks for the information, Rickie...... I almost understand I have a stick steer with an old 788 with a transom mounted TD and a 998 with the HDSI mounted on the trolling motor. Mainly use the 788 for GPS and depth reading when underway and will turn off 788 sonar when fishing due to crosstalk interference and just use the GPS. Also a "not so proud" owner of a repaired HDSI transducer with respliced wiring that I am thinking of mounting for DI from SI and a not in use transducer switch. If I were to get a Y cable, how would you hook this mess together so I could choose either SI or DI displayed on the 998 while the 788 shows 2d/Gps.

[rnvinc]

The 788 would still be connected to its own separate xducer ...
(and would still need Sonar turned off when using the 998 Setup)

Rickie

[rnvinc]

So which SI side of the repaired HDSI works correctly so that I can advise which pin to remove ...??

Rickie

[MonteSS]

Why not just buy a unit that shows good Di as is??

Sounds kinda Rube Goldberg to me.

Any shots with this mod?

[cache22]

Thanks for the information, Rickie..... I could probably use the universal 2d (presently disconnected) on the trolling motor and get by with 2 "y" connectors, but it would be a "Rube" arrangement as MonteSS says and would have an undesired tail hanging from my Terrova head. Was just looking for a way to get better DI from some of the extra pieces I have laying around. Guess I can live with DI from SI for now.

[rnvinc]

Why not just buy a unit that shows good Di as is??

Sounds kinda Rube Goldberg to me.

Any shots with this mod?

Some guys already have the HB SI units - want better DI - but don't have the funds to buy a dedicated DI unit ...

It is exactly Rube Goldberg ... But it works = for some ...

HB "DI from SI" (455kHz) ...


HB "DI from SI" (800kHz) ...


And now the same brushpile - Same Day - Same water conditions ...
HB HDSI rotated 60° (with the as SIDB Y cable) and displayed on the HB SI unit (455kHz) ...


HB HDSI rotated 60° (with the as SIDB Y cable) and displayed on the HB SI unit (800kHz) ...


I think the Rube Goldberg is pretty obvious ...

Rickie

[kosmo]

I took these shots,using the XNT 9 DI T transducer,on my 998's.This works best.No switch is needed,just ethernet the two units and share the transducers via advanced sonar menu.By doing this I could compare di from si with dedicated di.All from the same units. (The hdsi transducer rotated will give better results)........

[MonteSS]

Gotcha. Looks good