Topic: Transom or Thru-the-Hull Transducer?

[Boblagio]

I'm trying to decide whether to use a Transom or Thru-the-Hull transducer, in addition to the side-imaging transducer for my new 899ci HD si unit.

Please bear with me as I try to explain my situation.

Before I purchased my 899, thru discussions with sales people, forums, and Humminbird tech support, I came to realize that the side-imaging would not work properly at higher (above 15-20 mph) speeds.

I currently have a Humminbird Matrix 37 as my main unit, with a thru-the-hull transducer that works perfectly. And Humminbird Support told me I could use a "Y" splitter, using my current Matrix transducer and the side-imaging transducer (which, after reading some posts here, have decided to exchange for the HD one). However, I read on the Humminbird website that the latest software for the 899(v7.590) is removing support for Quadra Beam transducers - and the Matrix 37 is a Quadra Beam. I called support again, and was told I could buy a new Dual Beam transducer, or just not upgrade my software (which Humminbird says is v7.460).

So, I'm trying to determine my best option, so I don't have to do multiple installs.

Here are what I see my options as:

A) Use my Y splitter with my current Matrix thru-the-hull transducer, and never upgrade my software on my 899 side-imaging unit.

It seems though, that I might want to update the software at some point in the future.

B) Just keep the Matrix 37 on my boat, and add the 899.

I could use the Matrix for down imaging and the 899 map (I have the Navionics Hotmaps Platinum) at higher speeds. But, it would be pretty crowded on my console with both units.

C) Purchase a new dual beam thru-the-hull (Humminbird said I would need the XP 9 20).

Since my current thru-the-hull is epoxied-in, I think I would just disconnect it, and epoxy the new one beside it, but am not certain. I don't feel comfortable doing this myself, so I'd have to pay to have it done (upwards of $200)

D) Purchase a transom mount transducer (Humminbird says XNT 9 20).

My concerns with this are: 1) I have a '97 Hydra-Sport with a stepped hull, and don't know if I'll get good readings, and 2) I've read the transom mounted transducers can "become detached"at higher speeds - the max speed of my boat is about 60 mph.

However, this would be an easier installation, and I could do it myself as I have mounted a transom-mount transducer myself on a previously owned boat.

So, sorry for the long explanation, but I've been saving for several years for a Side-Imaging depth finder, and really want to choose the best possible option.

Any help will be GREATLY appreciated! Either with one of my options listed, or some I've not thought of.

[ITGEEK]

Boblagio:
Here's my 2-cents.
Since the Matrix is working so well, I'd keep that for 2-D and down-imaging.
Also, you may get good 2-D readings at speed.
Mount the 899 transducer on the transom, temporarily and test it out.
It may take you some time to find the very best sweet spot for your boat.
Get yourself a transducer mounting plate, so that you only need to put two screws in your boat.

Be aware, though, that if you want good or any 2-D readings at 60 from a transom transducer, you may be very disappointed.
If the 899 works out well, you may be able to get rid of the Matrix.
Be aware, that if you try to use both sonars at the same time, you may get sonar interference.

[rnvinc]

I agree with ITGEEK ... Keep the Matrix as is ... At least until you realize you don't use it enough after the 899 install ...

I have confidence you could efficiently install the XP 9 20 shoot thru with the AS SIDB Y cable setup ...

Be sure to test the area before the epoxy step ...

Here is a good guide for shoot thru installation ...

http://www.bbcboards.net/humminbird-sonar-gps/172972-installation-networking-information-resource.html#post1538600

Rickie

[Boblagio]

Thanks for the suggestions!

I will definitely get a transducer mounting plate - I don't want a lot of screw holes in my transom.

I've seen a lot of Doug's posts over on BBC, but had not seen the ones in the link. I've installed a transom mount transducer before, but have never worked with epoxy; have only read that if you get air bubbles in it, the transducer won't work properly. After reading Doug's explanation of how to install a thru-the-hull, I think I can probably do it.

One other question - I've also read where you want to keep the transducer cable away from other electrical wires to prevent interference. With my boat, this doesn't seem possible, as they all run from the console to the back bilge area inside the boat beside the driver's seat. Would it not help to put a shielding sleeve or wrap on my new transducer(s) cable?

[rnvinc]

TM power wires seem to be the most common culprit for EMI/RFI ...

Shielding Definately couldn't hurt ... But also may not even be necessary ...

Interference is such a variable gremlin ... Some boats have it ... Some don't ...

You might install as is and test for interference ... You may get lucky and not ever see it ...

Rickie