Identifying this Speed Transducer Insert, Help! Lots of pics.

[enzeno]

TL;DR, I need to identify this speed transducer for a replacement or suitable substitute, or blank (o rings for blank). 5 Pin, going to Raytheon ST 60 Tridata. Full Story Below.


I have found myself in a bit of a mystery that I am trying to solve. We have a 1999 Gemini 105M that has a Raytheon Tridata ST 60 with Autohelm Branding. The Speed transducer stopped working on us, and when trying to service it, it physically broke upon removal. The boat was thankfully out of the water.

So the pictures are of both the transducer (with plastic broken off of the top) and the blank. So I cannot re-insert the transducer insert because it is broken. The blank had bad O-rings, and the replacement O-rings are too large. There is absolutely nothing identifying them, on the cable or anywhere on the plastic.

On the Gemini it is in a thruhull brass fitting. Approximately 2" thruhull. I tried capping the thruhull with a brass cap with something that was very close in size, but it was just slightly too small.

So at this point I have an open thruhull. Aside from removing the fitting and glassing the area, I am trying to find a replacement. In the next season or 2 we will be replacing the electronics, but we do not want to do that yet. I am trying to find a replacement transducer, a replacement blank, or at least know the correct O-rings for the blank.

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Charlie,

The subject transducer is a very old ST80 Speed transducer which had been designed to be interfaced to a dongle which was in turn interfaced to the SeaTalk bus. Unfortunately, Raymarine no longer has replacement inserts or parts for this transducer. If seeking to replace the transducer then it would be recommended that it be replaced with an E26031 ST800-P120 Analog Speed Temp Transducer. The leads of this transducer will be mated directly to the Speed / Temp transducer terminals on the back side of the ST60 Tridata display.

[enzeno]

Thank you Chuck. I have ordered the exact thing you have recommended. I will report back with the outcome. I don't know how old is "very old", but I would expect the transducer to be similar in age to the boat, which would be 18 years old this year. Is it possible that it would be dramatically older than that? As in, older parts from another boat for instance? Just curious.
Thanks again,
Charlie

[Chuck - Raymarine - Moderator]

Charlie,

The transducer shown was phased out shortly after your boat's manufacture date. This transducer would have typically been used with a ST80 instrument system rather than a ST60 instrument system.

[enzeno]

Thanks for the response. So received the ST800 today, and I have found that the transducer is skinnier than the old transducer which means I have to replace the thru hull. Is this my only option to replace the entire bronze thru hull? No other transducer fits where that old transducer fits? Also, is there a part number for the o-rings? So that I could just put the blank back in?


Charlie

[Chuck - Raymarine - Moderator]

Charlie,

Q1. I have found that the transducer is skinnier than the old transducer which means I have to replace the thru hull. Is this my only option to replace the entire bronze thru hull?
A1. Yes.

Q2. No other transducer fits where that old transducer fits?
A2. No transducer currently sold by Raymarine features an insert which will fit the transducer housing of your current transducer.

Q3. Also, is there a part number for the o-rings? So that I could just put the blank back in?
A3. Raymarine has never offered o-rings as a separate part number. You may want to consider bringing the insert to a hardware store to seek replacement o-rings.
Also, whereas your currently installed transducer was initially manufactured by Airmar, Inc. ((603) 673-9570), you may want to consider contacting them for these o-rings.