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I need to replace my instruments- 1970's vintage datamarine. I picked up raymarine st60s at great price on close out. The current depth transducer is a datamarine glassed to the inside of the hull. There's no indication it actually goes thru the hull. I'd really like to reuse this if I can but the specs say its a 210 hz unit and I think the airmar that comes with the st60 is 200 hz.
1. Will the old transducer work? I'm guessing not.
2. Will it damage the st60 head if I try it?
3. If the datamarine transducer won't work due to frequency mismatch, My understanding is that I can bed the new airmar transducer which is designed for thru-hull installation and use it as an in- hull transducer if properly bedded. Is this correct?
 

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1. Maybe, maybe not.. give it a try...

2. No reason to think it can damage the head.

3. You can try that.. depending on hull thickness/construction you may lose some range.. installing it in a 'wet box' rather than simple bedding might produce better results. You can test that plan by filling and sealing a ziploc bag with water and experimenting with placement, putting the transducer atop the bag and see what reading you can achieve.

FWIW we hooked up a 'new' ST40 head to a 25 yr old Signet tranducer, had to sort out the wiring but no big deal.. works great and doubled the depth range vs the original Signet head. Of course we don't get temperature, since the transducer doesn't have that sensor. An in-hull install negates that feature anyhow..
 

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highly unlikey question here but have any of you guys managed to rig a fishfinder display like say a garmin 150 to a signet transducer like faster has done?

My signet transducer has 3 wires...if I can use the transducer the garmin fishfinder came with as a backup and vicerversa that would be too awesome

I plan to get some sort of display for the signet setup but they are so expensive...something in the $100 range would suit me just fine NOT 300 or so
 

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I bought the ST40 (out of production) new for $150 with a transducer I didn't need. The depth function has a send, receive and shield.. the connections to the garmin/whatever will likely have those plus temperature inputs. You can get the wiring diagrams off Airmar's site in most cases, so you can figure out the colours. Just a matter of separating those three critical wires and trying them until you get a pattern that works. The manual for the new head may or may not help depending on whether it's wired up individually or it's using a preformed plug connector (in which case you'll need to cut it off and adapt things cable-wise) But it's just wire - no black magic here.

I think the biggest issue will be frequency mismatch - but the transducer is really just a crystal that gets 'excited' by the head and the return interpreted by the head so if kinda close may well work fine, as it did for me.

The broadcast pattern on a 'fish finder' might be more complex and you may get only depth, but that should do...
 
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