Airmar P7 depth transducer

[kashurst]

I suspect my depth sounder is failing. There are two Simrad IS12 display units linked together, the lower helm one has the speed and depth sensors connected to it. From time to time the depth reading goes to --- which, according to the manual, means no contact with sensor.
I have checked out the contacts several times and it seems to be getting worse. It also seems to be depth related. Less than 20m all seems well, once I go deeper than that, it seems to loose it, until I return to shallower water again.

Anyone experienced this and was it the sensor?

 

[Jamie Dundee]

Any chance of fouling on the transducer? Losing depth in deeper water is, in my experience, linked to incorrect td angle or fouling of the td. Assuming yours is through hull the angle shouldn’t have changed.

 

[Hurricane]

I think these sensors are filled with oil.
I had a similar experience with mine - and I have two.
Whilst we were out in the boatyard, I noticed that one was dripping oil.
I think that the travel hoist straps often clash with it so I think that a build up of barnacles squashed by the hoist's straps cracked it.
Once replaced, everything worked.

 

[Whippersnapper]

I have a Airmar P9 but it is mounted inside and shoots through the glass. They have glycol as a coolant and transmission media. If yours is similar you may find it just needs more glycol. That solved the problem for me.