Transducer Compatability

[salty_dog_68]

i am in the process of purchasing a pre-owned sailboat. the knot meter and depth instruments have long since become inoperable. my question is...if i can not find an exact replacement can i use the transducer from the old stowe instruments with a different mfg. of instrument? should they be compatible? do the trx of different mfg. use different "languages" to transmit data to the instrument ? how long should a bronze t/h trx last? thanks.

salty

[swagman]

I believe you'll find it depends on the model and age.

I do know some modern kit use not just the same format of data but also the same paddelwheels......but if you ask the manufacturers you'll get your answer.

Cheers
JOHN

[exposure]

Airmar makes most of the transducers on the market today. You can go to their web site and use the cross reference to find the model and specs of your transducer, then find other models that will work with it.

http://airmar.com/

I went through the same thing when I bought my boat. However, my instruments were too old and did not show up on the cross reference list. I ended up bonding a depth transducer inside the hull, and living without a knot meter (I used a GPS) for over a year until the next haul out when I put things right.

Woody

[Jentine]

what **** cans are for. Include new instrumentation in the cost of the purchase. You will be starting from scratch and won't have to worry about junk instruments for the next ten or so years. It is a sound investment.
Jim

[tinley]

Stowe transducers are unique to Stowe, (including Robertson Dataline & IS11). Airmar do not manufacture a 205kHz depth transducer required for Stowe. Stowe Marine still manufacture new transducers for speed, depth and wind for any existing Stowe instruments and also manufacture new instruments that will work with any existing Stowe sensors.

As for the comment by Jentine... that all depends on how deep your pockets are... if spares are available, repair or update your existing instruments!

[Solitude]

New depth sounders are not that pricey. You may want to compare the cost and time spent with just purchasing a new one. That being said it may not mount the same way.

[GordMay]

Paddle Wheel Type Transducers:
A Paddle Wheel type speed sensor consists of a magnetized paddlewheel, wherein the paddlewheel is rotatably supported in a cavity adjacent to a (Hall Effect) magnetic sensing device. The sensor generates electrical pulses corresponding to paddlewheel speed, as the wheel rotates when the vessel moves through water.

Knot Log Tap-Test:

1) With 12VDC Power and Instrument “On”; remove the coax cable from the connector found on the rear of the speed instrument (display).

Bend a paper clip into a U shape and place one end of the paper clip into the centre hole of the connector (signal) on the rear of the unit.
With the other end of the paper clip tap on the outside (ground shield) of the same connector (essentially shorting the inside pin to the outside collar) rapidly while watching the display.

If the speed increases as you tap, then the instrument is capable of producing a speed. You should be able to see about a 5 knot speed with rapid tapping.

If not; you will need to service or replace the instrument.

If this is ok, proceed to the next step.

2) Re-connect the cable to the rear of the knot meter, and locate the Paddle Wheel Speed Sensor in the hull.
Follow the cable about 10 feet back, and disconnect the cable at the junction.

Perform the same tap test at the end of the cable leading to the knot meter, by shorting the center pin to the outside shell.
Have someone observe the reading on the knot meter.

If you can produce a good reading on the knot meter, then the inter-connect cable is ok, and you will need to check the Paddle Wheel.

3) Remove the speed sensor from the thru hull fitting, and insert the dummy plug (if afloat).
Spin the paddlewheel by hand. If the display shows a speed you will need to replace the Paddle Wheel Transducer assembly.

If it does not show a speed, you will need to replace the Instrument.