Topic: Helix 7 DI/SI with 2 transducers

[Sewerdude]

First off,Im very very new to any type of fishfinders. Ive a Helix 7 DI/SI on my boat (transom) now and I think I can simplify the transducer mounting issue with 2 different transducers. The Helix 7 came with a XNT 9 SI 180T, Id like to somehow also use some type of transducer for 2D down imaging and just use the XNT for SI.
Ive read about a switch, or a Y harness, plugs etc.
Could somebody point me in the right direction as far as what I would need to run 2 transducers to my Helix 7? As in which Y harness or switch etc? Or do I even need switch, will the unit automatically read off the SI transducer if I scroll to that screen? Then back to the DI transducer if I change screens?
Thanks!

[Bob B]

If all you are wanting to do is get the 2D from the front transducer and the SI from one mounted on the back......The Y cable is the easiest way to do that.  It electrically connects a separate 2D transducer instead of using the 2D from the Si transducer.

http://www.humminbird.com/Products/AS-SIDB-Y/

The only thing I'm not sure about is if the pin out of the cables will work to with your existing DI transducer to accomplish this.......I think it will, but I'm not sure.  The other possible complication of using your existing transducer is that it is probably has a 200/455 element for the 2D transducer.....and when you have the SI transducer selected in the transducer selection menu it is expecting a 200/83 2D transducer.

For typical installations, people normally use either a shoot thru 2D transducer like this https://www.amazon.com/Humminbird-XP-20-Puck-Transducer/dp/B000G6637C/ref=sr_1_1?ie=UTF8&qid=1471627702&sr=8-1&keywords=xp920

or for a transom mount one like this https://www.amazon.com/Humminbird-XNT-Transom-Mount-Transducer/dp/B000MPO8R4/ref=sr_1_1?ie=UTF8&qid=1471627455&sr=8-1&keywords=xnt+9+20

What seems like something simple isn't as simple as if first seems.  The other complication is that it is best to have the transducers and GPS located as close as possible to each other to improve the accuracy of waypoint marking.

I don't know if I have helped or confused you more.  I just wanted to make you aware of as many of the factors involved as possible.

So, If you want the 2D from the front and the SI from the back of the boat, get the Y cable and one of the 2D transducers listed would be guaranteed to work.....but not necessarily optimal since the 2D would be quite a distance from the SI and GPS.

You could also just mount the SI transducer up front and then have no need for the Y cable and separate 2D transducer .... but you would still have the issue of GPS distance from the GPS.

If it were me, I would try to find a way to mount the SI transducer as close to the Helix as possible.

[Sewerdude]

Thanks for the reply Bob!
I actually wanted to mount both the XNT 9 SI 180 T and another ducer on the back (transom). The reason is, where I would like to put the si ducer, isnt a good place for the 2d ducer, so I can get a good on plane reading....so, I thought it would be better to have 2.
Would this one work? https://www.amazon.com/Humminbird-710198-1-Transducer-Temperature-Transom/dp/B000MPMHK4/ref=sr_1_1?s=electronics&ie=UTF8&qid=1471631415&sr=1-1&keywords=Humminbird+XNT+9+20+t
Would there be any interference so to speak?

[Bob B]

I don't think you need the one with the temp sensor in it.  I think the temp will still come from the SI transducer....but it won't hurt to get it if you ever want to use it as a stand alone 2D transducer.....Only $5 or $6 difference between it and the one without that I linked in my previous post.

I think the one you linked to there is the one I used, but don't remember for sure.

[Bob B]

Ignore everything I said about the DI transducer .... I got 2 threads mixed up

The last couple of posts were OK

[rnvinc]

Just to add a little to Bob's info ...

When using the AS SIDB Y cable on a HB SI unit ...

*SI/blended DI from the SI piezoes/and Temp will always come from the SI xducer ...

*2d will always come from the added 2d xducer ..

(You mentioned in your OP about 2d and DI coming from a 2nd xducer = this is not possible with the AS SIDB Y cable because there is only 1 wire for the 2d piezo and 1 wire for drain/ground in the Dual Beam leg of the AS SIDB Y cable) ...

Rickie

[Sewerdude]

So the "new" XNT 9 20 will only read 2D and my stock XNT 9 SI 180T ducker will read @D and SI? Is that correct?.... Is there anything wrong with that?

[Bob B]

The 2D will only come from the XNT 9 20. 

SI will come from the XNT 9 SI 180T..... DI is derived via software from the SI beams.

[Sewerdude]

I got both transducers mounted for the Helix 7, mounted both the "new" XNT 9 20 and the XNT 9 SI 180T and I took it for a test yesterday...Yes, I'll have to do alittle fine tuning to get them right on the transom.... But, I seem to have lost my 455 khz..ugh! I tired the 2d, SI and the Sonar...The only options I have are 200, 83 or 200/83 on all of them... Am I missing something here?

[Bob B]

Try to reset defaults and see what you get.

[Sewerdude]

Ok, I'll try that tomorrow Bob.
Thanks

[Sewerdude]

I tried resetting the Helix 7 to default...No change, the only KHZ I can pull up on the Sonar tab is 83, 200 or 200/83...I also have a Helix 5 DI on the bow and it allows me to view/change up to 455khz.. Is the Helix 7 not allowing me to view this because I used a Y cable and a XNT 9 20 for the 2D which is only 200 and 83 khz? I have the original XNT 9 SI 180 T and using it for the SI and DI... Any suggestions why I cant view the 455khz?

[Bob B]

In the 2D menu, the 200/83 are the only frequencies you will have..... Those are the frequencies used by a SI unit for the 2D.  I don't know what is in the menu for the SI frequency for the Helix 7 SI .... it will only use the 455 Khz frequency for SI, so maybe there is no frequency selection.  Those are the only 2D frequencies you will have whether you are getting the 2D from the SI transducer or from the the XNT 9 20.

The DI unit does have different frequencies for the 2D with the transducer that comes with the unit.... they are 200/455. 

[Sewerdude]

That makes sense Bob. Thanks! I appreciate it.

[rnvinc]

Bob is correct ...

You have no "Imaging Frequency" selection "Menu" in the HELIX 7 because the HELIX 7 is only capable of transmitting 455kHz imaging ...(and the 200kHz/83kHz 2d transmit of course) ...

Rickie

[Sewerdude]

Thanks! It had me a little worried there..I'm learning a lot thanks to you guys!