ST 50 Plus Transducer

[B310Racer]

I have an Autohelm ST50 Plus Tridata head unit. My depth works fine. My speed is intermittent to non existent. I read the post titled ST50+ Tridata and plan to run the test shown there on the paddlewheel.

I do not know the part number of the transducer - Can you identify from the attached photo? The cable shows "Airmar Transducer Cable #C9 C1225" but there are no markings that I can see on the transducer itself.

Questions are:
1. If the paddlewheel is not showing correct function with the Ohm meter, are there replacement parts available to replace/rebuild the paddlewheel portion of the sender? part Numbers please.
2. If not, what sender is the correct unit to replace mine without having to replace the through hull? part Numbers, please.

Appreciate your replies.

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum B310Racer,

Q1: I do not know the part number of the transducer - Can you identify from the attached photo? The cable shows "Airmar Transducer Cable #C9 C1225" but there are no markings that I can see on the transducer itself.
A1: The pictured transducer appears to be a ST800 / P120 (Plastic) ... current part number is E25025.

Q2 & Q3: Please click here to view a FAQ addressing these questions. It is recommended that Gemeco be supplied with a photo of the transducer in order that they may positively identify the model of the speed/temp transducer.

[B310Racer]

Thanks, Chuck. Is this the place to get guidance on replacement head/transducer units if I should choose to go that route? Or, can you direct me to the proper source?

[Chuck - Raymarine - Moderator]

B310Racer,

This is indeed the correct place to request recommendations for replacement instruments and transducers.

[B310Racer]

OK.
Here is what I currently have:

ST50 Plus Tridata Head unit, Speed (Temp?) transducer (Model TBD) that I discussed earlier, separate depth transducer (Model Unk). I also have a wireless wind direction/speed unit at the top of the mast that is feeding a Tacktic MN 100 - 2 head unit. I'm assuming that all of these are analog.

Can you recommend replacement/upgrades - preferably with a minimum of disruptions (through hull replacements). Or, at least a reasonable plan to move out of the older items and into the more current technologies. I think in the long run I want to be able to run a backbone (2000) to connect everything including my Fusion AV700 stereo and a more current VHS.

[Chuck - Raymarine - Moderator]

B310Racer,

With respect to changing out the ST50+ Tridata Head, it may be replaced with an
- i50 Tridata or
- i70 Multifunction Instrument Display and an iTC-5 analog instrument converter.

Both of these option would support being used with the currently installed thru-hull transducers should they be operational. The latter option has the advantage of multi-point speed calibration, providing more accurate speed data across a wider range of speeds.

Should the Tacktick system be operational and should you desire to interface it to either of the above listed items, then it would be recommended that a TackTick T122 Wireless Interface be installed. The TackTick T122 Wireless Interface may be interfaced to a powered and properly terminated SeaTalkng backbone to which either of the above listed options may be interfaced to support sharing of data between the two systems. An Actisense NGW-1-STng would be installed between the TackTick T122 Wireless Interface and the backbone to support bridging of data from the TackTick system to the SeaTalkng backbone.

[B310Racer]

Thanks, Chuck. Appreciate your assist.

[Chuck - Raymarine - Moderator]

You're welcome.