another annoying question about instrument compatibility. Log transducers

[jimmyk]

Sorry about this. Will any log transducer fit any instrument head. Eg Old stowe log transducer and nasa head. Or even old stowe transducer and raymarine head. I think I already know the answer but asking anyway

 

[prv]

Many will as they all share transducers made by Airmar, but I wouldn't be so confident with old Stowe stuff. That might be from before Airmar cornered the market.

Pete

 

[lpdsn]

Sorry about this. Will any log transducer fit any instrument head. Eg Old stowe log transducer and nasa head. Or even old stowe transducer and raymarine head. I think I already know the answer but asking anyway

I specifically looked into replacing the Stowe head with a Raymarine (Airmar) DST 800 head. Different diameters unfortunately.

 

[pvb]

Sorry about this. Will any log transducer fit any instrument head. Eg Old stowe log transducer and nasa head. Or even old stowe transducer and raymarine head. I think I already know the answer but asking anyway

The real answer is "maybe". With old-style Hall effect logs, the transducer outputs a pulse every time the paddlewheel rotates. As the water flow over the paddlewheel can vary according to hull shape, all instrument heads include a calibration facility. The extent to which the reading can be changed varies by manufacturer. Old Stowe displays could be varied from 2.5 to 197.5 (where 100 is the default setting). Raymarine i40 displays can go from 25 to 250 (again, with 100 as default). Nasa displays only tend to go from 70 to 150. So, you could try another make of display and see whether you can calibrate it to get an accurate reading. You might well be lucky.

With new-style NMEA2000 transducers, the output is an NMEA sentence, so can be used with any NMEA2000-compatible display. So the problem will decrease in the future!

 

[macd]

So the problem will decrease in the future!

I've been hearing that all my life. One of these days it'll come true...

(Coincidentally I'm about to replace three Stowe transducers with Lewmar/Airmar. I don't expect much straight swapping to be going on, although naturally I'm thoroughly looking forward to running the cables, filling holes, making new ones...all the things that make boats such fun:ambivalence

 

[biscuit]

You could do what I did and keep your Stowe transducer(s) and fit Echopilot Bronze Trio display(s), which can be calibrated to suit the frequency of your transducer. (? 205 mHz for Stowe). I had a faired in Stowe depth transducer that I was unwilling to sacrifice. These displays are completely versatile.
I fitted 2, so can see Speed/ Depth on one and GPS repeater on the other, but there are lots of alternative displays, easily toggled from one to another.
They are not at all expensive, and great value for money.
I have posted about these before and am puzzled that they are not better known.
Good luck.

 

[Jamesuk]

We found the New Raymarine instruments will only work with transducers that are old if you have the 'pod system' speed, wind, depth as the new ITC5 is not backwards compatible.

'Yes we have bench tested it and it all works'
We find out trip log, temp and a whole lot of basic features are not adjustable or can't be reset so very much read only. The pods are back in with the ST70+ and the ACU400 all works fine with no bugs (yet)

 

[ianj99]

Sorry about this. Will any log transducer fit any instrument head. Eg Old stowe log transducer and nasa head. Or even old stowe transducer and raymarine head. I think I already know the answer but asking anyway

I am hoping an old Smiths paddle wheel transducer will work with my old Seafarer WDS speed/log/depth instrument. If not, then I have already built and tested a pulse to nmea VHW sentence interface. The Smiths is said to generate 5pulses per second per knot but my interface can accommodate other pulse rates if anyone wants to connect an old style transducer to a nmea (0183) input. The Smiths is a 2wire inductive sensor but a 3 wire Hall Effect type can also be used.

http://www.ybw.com/forums/showthread.php?417883-Diy-analogue-speed-to-nmea-interface

Ian