Topic: 798 ci HD SI with US 2

[leoniru]

Extremely green newbie here (waiting for my 798 to be delivered today). I am currently on the fence with regards to getting a trolling motor with (Terrova) or without (Riptide ST) Universal Sonar 2.
I've been searching this forum a bit and haven't seen any posts directly related to utilizing a bow mount TM with US2 tied into an SI sonar unit.
So, is this combo of any value at all, or would this money be better spent elsewhere?
Primary use will be shallow (<20') water fishing on small lakes and rivers.
Thanx,
leoniru

[RGecy]

leoniru,

Welcome to the forum.  The downside it you would lose your Side imaging and Down Imaging when you switch over to the TM Transdcuer.

Why not save your money and buy an extra SI transdcuer for your unit to mount on the Trolling Motor?

Robert

[leoniru]

Roger;
Thanx for the welcome.
Your suggestion is what I was also thinking. I also wondered if a motor already having the built-in US2 transducer might somehow prevent one from installing another SI transducer onto it. I don't know if the US2 transducer could be removed and replaced or if the motor's housing is modified such that there's no room left to clamp on another transducer properly. As far as I can tell, the Terrova 55 with factory-installed iPilot is not available WITHOUT US2, and as I want both a foot pedal and the iPilot, I'll have to get the saltwater Riptide ST 55 as this is available with factory installed iPilot and no US2. The Riptide however, does not come standard with the footpedal but one is available as an accessory.
Perhaps someone out there that owns or has owned a Minn Kota with US2 could comment on the motor housing/transducer setup and whether or not it's possible to either replace the US2 transducer with an SI one, or just leave the US2 transducer there (and unused) and clamp on an SI transducer.
The few comments I've seen so far on forums regarding Minn Kota's US2 have generally not been favorable one's.
One would think that being as how both Humminbird and Minn Kota have the same parent company, that there would be some or preferably a LOT of crosstalk between them especially considering how these products are both aimed at fishing applications. Seems to me that a Minn Kota motor should have a built-in  SI 'ducer option!

[Humminbird_Greg]

The US2 cannot be replaced with an Si transducer as there just is no room to do so in that same opening.  The trolling motor is large enough to allow and Si transducer to be mounted to it though.

[leoniru]

Thanx Greg,
I ended up buying the Riptide ST 55 with iPilot and will be adding another SI transducer in the not-too-distant future. I also just got my 798 ci HD SI (yeah, the wife isn't too happy with me at present) in, and while looking it over I found myself wondering just exactly what is the difference between the included stock (XNT 9 SI 180T) transducer and the XHS 9 HDSI 180T? The only thing I can find out on 'Bird's website is that the latter's 800 khz beam is not functional if used with the 798, but what exactly does this mean from a practical standpoint?

[Humminbird_Greg]

It means that you will not be able to have the more detailed Si sonar images that the 800kHz can give you – but the 798 unit is not capable of producing and using the 800kHz anyways.  The HDSi transducer also allows for a little more detail in the 455kHz as well due to its longer Si elements, which some can see on the 798 units (and some cannot see the difference).

[leoniru]

Thanx again Greg - this info helps. I won't be spending an extra $60.00 or so on the XHS 'ducer if it MIGHT give me a bit more detail on the 455 khz band. I'll likely add a second XNT if I add a second 'ducer at all. I plan on trying the stock transducer both on the transom and the trolling motor to see if one position is noticeably better than the other in terms of image quality. My Alumacraft Jon boat has a riveted hull and I suspect the transom position will be plagued by air bubbles unless I mount the 'ducer on a 'stem' which would position it several inches lower than the hull bottom.  I just don't know as this is all new territory to me.

[Humminbird_Greg]

“I won't be spending an extra $60.00 or so on the XHS 'ducer if it MIGHT give me a bit more detail on the 455 khz band.”
There is no doubt that the larger HDSi transducer will give more detail on the 455kHz frequency – the doubt comes in as to whether you will be able to see it on the smaller 5-inch display on your unit or not.  Inside on a larger computer monitor the difference is quite noticeable.

[Razzy43]

Greg,
If I am reading this right, the 798 is compatible with the Terrova US2?  I read another post where you state it isn't.   Before I spend $1500 on it would like verification.

[Humminbird_Greg]

I just checked on this so I had the “official word”: it will work if you select the DualBeam type transducer (Transducer Select menu) and reduce the Sensitivity menu setting.

[Razzy43]

Greg,
Thanks for checking on that for me, saves me from buying a unit to mount with the TM.  When you say to adjust the sensitivity, as in reduce it, will there be problems if I forget this or it is set too high?

Right now I have the 798 sitting at my console and the transducer mounted on the transom.  I should be receiving my Terrova US2 with I Pilot Link today, so for me to be able to use both transducers on one unit, I would need to add in the AS SIDB Y splitter?  This will allow me to get the DI/SI from the transom mounted transducer and the 2D sonar from the TM?  If this is the case, am I able to when the TM isn't in use, be able to receive the 2D soner from the transom mounted transducer or would I need a switch for this setup?  I read in another post that the splitter basically redirects the 2 sonar only signal between the transducers.

or would the TS3 switch replace the splitter and give me control over which 2D sonar I am seeing on the screen?  Basically I am wanting to use the transom transducer for normal driving conditions, using the SI for finding structure, and plotting tracks for the I Pilot to follow, then using the US2 TM transducer while truly fishing.

[Humminbird_Greg]

If you forget to adjust the sensitivity lower Razzy43 the 2D sonar will just look over-powered which won’t cause any problems other than in viewing the 2D sonar.

When using the AS-Si-DB-Y splitter cable, the 2D sonar will always come from the 2D transducer (the US2 in your case).  So when the trolling motor is out of the water the 798 unit will not be receiving a bottom reading which will mess up the Si and Di sonar (they require an active water depth reading).  Using the TS3 Transducer Switch is the better option for you due to the way you have described how you want to use your 798 unit and its 2D sonar.

[Razzy43]

Thanks Greg, saved me from buying the wrong stuff and a lot of headaches!!!!