Topic: 998c HD Si shoot thru the hull

[hgv]

Which transducer will allow me to "shoot thru the hull" so I can have down imaging at high speeds?

What device gives the 998 the inputs from the motor to get the digital speed and tach read outs on the depth finder?

Will a shoot thru the hull work on a kenner tunel hull?

[hgv]

here is a picture of the tunnel hull

[Humminbird_Greg]

hgv,
The only Down Imaging capable transducer that we have that can shoot its sonar signal through the hull is one of the dedicated DI transducers: XIH-9-DI-T. Which model Humminbird unit are you looking to use this with?

It looks to me like you would have to install the shoot-thru transducer on one sode of the tunnel or the other.  I am unfamiliar with the Kenner tunnel hulls construction but it would have to be in an area that has fiberglass only between it and the water (less than one inch thick).

Motor inputs to a 998 unit are made through the AS-ETH-NMEA2K NMEA 2000 Black Box.

[hgv]

it is for a 998c HD SI

[Humminbird_Greg]

The 998c HD Si unit can be made to work with the XIH-9-DI-T transducer.  I would recommend using a TS3 Transducer Switch for this.  When you select to use this transducer you will not have left or right Si sonar and you will need to set the Down Imaging Beam Width menu to the Wide setting for it to work.
Note: when you look at the Si sonar there will be sonar returns in the right Si beam but these are really DI sonar images.

[hgv]

So one transom mount transducer, one shoot thru hull transducer and a switch to switch between the two - hull mount for running across the lake at speed and the other for all other conditions.

I had a thru hull on a bass boat and a transom mount unit on the same boat with no switch Had readings up to about 40 mph and good SI up to 6 mph ??

[Humminbird_Greg]

hgv,
This may be confusing but...

You probably did have an inside-the-hull transducer and a transom mounted transducer on another boat connected with the AS-Si-DB-Y cable (no switch).  The difference here is that you wanted “"shoot thru the hull" so I can have down imaging at high speeds”.  The only transducer we have with that capability is the XIH-9-DI-T which is a DI model transducer.  If this is what you want to use you will need the TS2 Transducer Switch to go from the dedicated Di sonar to the Si/Di sonar of your 998’s transom mounted HDSi transducer.

Now, whether you need an additional inside-the-hull 2D transducer for high-speed water depth readings is a different matter.  The XIH-9-DI-T will work for 200kHz 2D sonar but not for the 83kHz 2D sonar.  If you never want to use the 83kHz sonar than there is no problem and you can just use the TS3 with these two transducers.
If you want to use the 83kHz at fast boat speeds you will either have to mount the HDSi transducer in a location where this is possible [Note: if this is possible you may also be able to use the Di sonar from the HDSi transducer and forget about the inside-the-hull DI transducer] or you will have to add another transducer to your set-up (XP-9-20 inside-the-hull 2D transducer plus the AS-Si-DB-Y cable) or use the made for trolling motor mounting XTM-9-WIDE-DI-20-T and mount it in the trolling motor [this transducer has the same standard 20/60 degree 200/83kHz 2D sonar as the HDSi transducer and the XP-9-20 transducer].

[hgv]

my head just exploded ................... 

[Humminbird_Greg]

I was afraid of that!   

[hgv]

Here is what I would like ......

1. Good performance at idle or trolling speed up to 6 mph - check
2. Down imaging at running speed - don't have well I do sorta, lots of vertical lines due to turbulence, although I should check this with max mode off hmmmm

[Humminbird_Greg]

If you are happy with what you have now - except for the DI sonar at speed: install the XTM-9-WIDE-DI-20-T inside-the-hull and test it by plugging it into the 998 unit.  If you like the results get the TS3 Transducer Switch.

[hgv]

why the switch, did not use it on the other boat just a Y cable

[hgv]

This is what I had on the other boat with a Y cable.    XFM 9 20

[rnvinc]

why the switch, did not use it on the other boat just a Y cable

The AS SIDB Y cable disconnects the 2d piezo in the HDSI and instead only connects the 2d piezo from the xducer in the bilge...(the DI piezo in the bilge in your case would not have a wire going to it.......no wire to the DI piezo = no DI data)...

The HB TS3 switch chooses 1 entire xducer or the other...

Rickie

[Humminbird_Greg]

Exact-a-mundo Rickie.

[hgv]

I see, so at high speeds I could flip the switch and have the in hull transducer then when idling or trolling flip the switch for the transom mount.

[rnvinc]

I see, so at high speeds I could flip the switch and have the in hull transducer then when idling or trolling flip the switch for the transom mount.

Correct...the HB TS3 switch allows using 1 xducer or the other...
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Now you will need to decide which dedicated DI xducer you want to experiment with as a shoot thru application ...

*The XIH 9 DI T with limited 2d ability (200kHz 2d will work- 455kHz 2d will not work)...

Better housing shape for shoot thru application...

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*The XTM 9 WIDE DI 20 T (200kHz 2d will work- 83kHz 2d will work)...
Housing may be difficult for shoot thru application...



Rickie

[Humminbird_Greg]

Just a thought here: besides the fact that the XTM-9-WIDE-20-T needs a larger mounting area because it is physically larger, it is easier for me to install due to its shape.  It is less prone to turn over during testing or when the epoxy is curing and is easier to balance something on top of the housing when that said epoxy is curing. 
Note that using either of these with the TS3 Transducer Switch will give you the temperature of the inside of the hull when that transducer is selected.