Frequencies of Raymarine & Stowe depthsounders

[Bajansailor]

We had Stowe instruments on Phoenix and they have all packed up now - the depth sounder was the final one to expire.
I have purchased a Raymarine ST 40 Bidata unit in replacement of these Stowe units.
The Stowe depthsounder transducer is a massively solid bronze unit, while the Airmar transducer that came with the ST40 unit is a very light (in comparison) plastic unit.
I am hoping that the Stowe depth transducer is still functional (and that the fault was at the display end) - if it is, I would like to use it (if possible) with my new ST40 display unit.
The Stowe transducer works on 205 khz, while the ST40 is on 200khz - are these close enough to be compatible?
The boat is currently ashore for a (very slow) re-fit.

 

[pvb]

Although they sound close enough to work, it may not be that simple. See this post regarding trying to use a 200khz transducer with a Stowe system. However, the poster does sell 205khz transducers, so may not be totally impartial.

I think you should ask Raymarine the question. You've already bought their transducer, so they can't try to sell you anything.

 

[Bajansailor]

Thank you pvb for the above.
Hummm, Mr. Tinley is basically saying that the Airmar 200 khz transducers will not be too happy working with the Stowe 205 khz unit.
So I shall take your advice and try to ask Raymarine about doing it the other way around, ie using a Raymarine ST40 unit with my Stowe 205 khz depth transducer unit (assuming it still works! But odds are hopefully that it does).

 

[Tranona]

Nothing wrong with the plastic transducer in a GRP boat. You can get a bronze one for an ST40 - I have one but only because it goes through a thick piece of Oak. Used a plastic log impeller through ply without any problems. Naturally bronze is a "close your eyes and pay" price!

 

[hightech]

The transmit and receive circuits in the head are finely tuned to the peak frequency of transducer and being off by just 1khz will kill the reply, this was a common fault we used to adjust for on units returned for no depth.

We also used to find that bronze transducers are more critical to frequency mismatch.

However, we did supply standard airmar transducers to go with Stowe databoxes and made no adjustments. The same transducers that you get from Raymarine. So give it a try, the worst that will happen is no depth shows (boat will need to be in the water.

 

[Bajansailor]

TNX Tranona and Geoff for the notes above.

I shall have a bash at seeing if the Stowe bronze transducer is compatible with the Raymarine ST40 display unit (assuming I can figure out the wiring - I hope they are the same colours / number of wires).

The bronze transducer is beautifully installed, sandwiched in two solid lumps of timber inside and outside th hull, hence I am reluctant to do anything to it.

If it does not work, then I shall try installing the plastic Airmar transducer next to it in a tube filled with oil (or perhaps try bedding it down on Blu-tack - I saw that suggested on here).

Is there a way of doing a check up on a Stowe bronze transducer using an electrical meter to eg test continuity between the different wires? I havent tried doing this yet.

 

[rogerthebodger]

I used raymarine (Airmar) on my simrad IS11 without any problem

Have a look at the airmar web site for compatibility