Thread: Proper transducer for HB 798 SI

My 798 came with XNT-9-SI-180-T and I use it on trolling motor.

The 798 units are shipped with the XNT-9-Si-180-T transom mount Compact Side Imaging (CSi) transducer as Denny stated; but I would encourage you to trade it in on an XTM-9-Si-180-T Trolling Motor mounted transducer (or the XTM-9-HDSi-180-T but that is more money) as it has an additioinal layer of shielding that you may or may not need, depending on how much RF interference your trolling motor puts off. Some prefer the more expensive and larger XTM-9-HDSi-180-T due to the more defined 455kHz Si sonar, but not everyone can see the added definition on the smaller 798 display (no the 800kHz Si sonar will not work with the 798).

Yes the 777 will work on the 798's base but you may run into some problems with the 777c using the 798's external GPS Receiver. The 777c was designed to use the GR16 GPS Receiver. The GR50 GPS Receiver which shipped out with the 798c Si units, was meant to be a direct replacement for the GR16 but they could not get it to work at the same current draw. The result is that the GR50 may draw more current than the 777c model can source and the result is that it burns out the GPS Receiver power circuitry that is in the 777c unit. Other than that, the 777c can use the 2D sonar part of which ever Si transducer you end up using.

Originally Posted by Humminbird_Greg

The 798 units are shipped with the XNT-9-Si-180-T transom mount Compact Side Imaging (CSi) transducer as Denny stated; but I would encourage you to trade it in on an XTM-9-Si-180-T Trolling Motor mounted transducer (or the XTM-9-HDSi-180-T but that is more money) as it has an additioinal layer of shielding that you may or may not need, depending on how much RF interference your trolling motor puts off. Some prefer the more expensive and larger XTM-9-HDSi-180-T due to the more defined 455kHz Si sonar, but not everyone can see the added definition on the smaller 798 display (no the 800kHz Si sonar will not work with the 798).

Yes the 777 will work on the 798's base but you may run into some problems with the 777c using the 798's external GPS Receiver. The 777c was designed to use the GR16 GPS Receiver. The GR50 GPS Receiver which shipped out with the 798c Si units, was meant to be a direct replacement for the GR16 but they could not get it to work at the same current draw. The result is that the GR50 may draw more current than the 777c model can source and the result is that it burns out the GPS Receiver power circuitry that is in the 777c unit. Other than that, the 777c can use the 2D sonar part of which ever Si transducer you end up using.

Thanks Greg, I was just concerned as to why HB would send a transducer with the "New" 798 HDSI that was not an HD transducer...

How long is the XTM 9 HDSI 180 T?

Also, doesn't the new 798 have internal GPS?

Thanks

Originally Posted by Don G

Also, doesn't the new 798 have internal GPS?

This may be wrong, but...

HB models with an "i" in the name are Internal GPS.
Models lacking an "i" are External. For example, the
"798ci HD SI" has an internal GPS antenna while the
"798c HD SI" is external.

I suspect the "c" desginates chartplotting, which
all the upper HB models provide.

Obviously, "SI" is side imaging.

"HD" means...high definition? I dunno. HB just
added two letters to make the latest model 798
different from the prior year.

Originally Posted by Denny

Don its 6 in. long and 3 in. wide.

Thanks Denny, if I go with HB I will definitely get the HD transducer..The additional cost of the upgraded transducer just might be enough that I will go with the Low HDS5..We will see..

It would be easier to go with HB since I already have a 777c2 mounted and can use the base for the 798..

Now I will have to see what modifications I will have to make on my MK Maxxum TM to make the 6" trans fit..

Thanks again

Don looks like the XTM 9 HDSI 180 T is 8.1x6.9x3.4 in.The XHS 9 HDSI 180 T is 6in. long.

Originally Posted by Denny

Don looks like the XTM 9 HDSI 180 T is 8.1x6.9x3.4 in.

Oh me, I don't think it will work unless I modify the skeg..

Originally Posted by HsvToolFool

This may be wrong, but...

HB models with an "i" in the name are Internal GPS.
Models lacking an "i" are External. For example, the
"798ci HD SI" has an internal GPS antenna while the
"798c HD SI" is external.

I suspect the "c" desginates chartplotting, which
all the upper HB models provide.

Obviously, "SI" is side imaging.

"HD" means...high definition? I dunno. HB just
added two letters to make the latest model 798
different from the prior year.

HsxToolFool,
You got most of it right. Here are the corrections:

The “c” designates a color display.

“HD” could mean one of two things:
- When used along with “Si” (HDSi) it designates the higher definition side imaging sonar frequency is usable by that unit.
- When used by itself as in the 798ci HD Si or 788ci HD it designates a higher pixel count display.

There is no 798c HD Si model units. All of the 2011 year model 798 units are internal GPS versions (798ci HD Si).