Compatibility 800 series paddle wheel transducer and older st60

[goboatingnow]

I have a 2003 st60 with a plastic paddle wheel transducer , the cable has failed right at the entrance to the transducer

Does anyone know of the 800 series transducer Is compatible with the older original unit , ie will it fit it to the thru hull

The older one is an SP800 ( E26031) the layer unit is the airmar ray marine one

[marcjsmith]

FWIW I just bought this unit form Imarine

https://www.imarineusa.com/Airmar31-487-3-71.aspx

my original was an st800 p120 retr PN 31-487-1-02 vintage 05/06 (see pics)

it was for my st60+


I did have to cut the end of the cable since the st60+ had the spade connectors rather than a plug

[zemurray]

i have exactly the same issue with my ancient ST650 transducer. I can wiggle the cable and get it going again, but I’m looking into swapping as you are. I’m pretty sure the new DST800 units are compatible, but I dont know that your display is. I was planning on calling airmar on the thru hull question when I get closer to dealing with it.

[goboatingnow]

My display is an ST60 so the newer st800 transducer is a direct replacement even though the head is different

We actually reoaired the old one by Dremiling the cable entry plastic away which revealed enough wire to resolder. The actual seal is further down on the transducer body

[marcjsmith]

always nice to be able make a repair and save money...

[j.g.evans]

I think all the transducers are made by Airmar and should fit in the through hull housing. Look at the ST60 manual to see if the speed can be calibrated in case the paddle wheel is different. If the boat is in the water have a swimming friend hold a suction cup over the transducer while you remove it. The wiring is not critical and you can splice away. Go to the Airmar web site if there is a wire color problem. The ST60 will not register speed if the temperature thermistor is not connected. Use a 10K resistor if the temperature function is not there.

[thunderhoof]

It seems like a common failure of paddlewheel transducers is wire breakage at the cable entry. After losing two of them to this failure I started adding heat shrink tubing about three inches long to the cable plus a gob of silicone sealant at the joint. This seems to have improved the situation.

[goboatingnow]

I can confirm the later transducer fits perfectly and has a better side entry cable gland. I have the original repaired transducer as a backup. No problems replacing in the water large valve “ flaps “ on the through hull limits ingress