Echosounder problem

[DavidTocher]

I've an old Seafarer 'whirring light' echosounder which seems insensitive. I have used it on another boat with Seafarer transducers and it seems to work OK.

Do the transducers age and become less sensitive? When the engine is running and the sensitivity set 'high' I get random flashes - again this could be because its picking up electrical noise as iy attempts to detect the weak signal from the transducer.

I rather like the 'whirring light' so is it worth replacing the transducer (if still available)?

 

[byron]

Try this. Disconnect the power supply from the boat's battery and insert a PP9 battery instead. You will find a compartment for this batter if you look inside. This may solve everything.
A PP9 will easily give you a season's work.

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[Paulka]

I had the very same syptoms one year ago, or so, after 20 years of good service.
Forutnately, I found the spare sensor, 20 years old as well, but never unpacked, and replaced the old one.
Hourrah! it works again!

Bad news : I have no replacement left, if it fails again in 20 years from now!

Good luck!

Paul

 

[charles_reed]

Running it on the internal dry battery may solve the problem of the interference, but if there is no signal to pick up, because the transducer is kaput, you're no further forward.

Nowadays most instrument manufacturers use the same proprietary transducer, but in those days the transducers were very much unique.

Surely however, the cost of a NASA depth sounder is going to be worth the saving of time, energy and frustration involved in trying to find a replacement.

As Stephen King says "The world moves on..."

 

[Guest]

Try this address they also have a web page but I do not know it
Mr. Scully.
Seafarer Research and Development,
32-40 Harwell Road,
Nuffield Industrial Estate,
Poole,
Dorset.
BH17 0GE
They are servicing my old 701 for me . They may be able to supply a new trancdoodly thing. Good luck Paul

 

[VMALLOWS]

If your transducer is in an 'oil bath' , have you checked this lately? Mine has leaked after 15 years and gives exactly same symptoms. The engine vibration stirs up bubbles in the oil, causing the random echos . I originally used castor oil as recommended but find it difficult to get today. ..... currently using 2-stroke oil.
Does anyone know the 'best' oil to use??

Vic

 

[bob_tyler]

If you try the PP9 9v battery experiment, get a good make. I had one of the early Seafarers years ago and it would only work properly with Ever Ready batteries and then only intermittently with Vidor. If I had it today I would use a 9v Duracell. I don't know about rechargeables.

 

[Guest]

I agree with VM - could easily be the oil bath. I was advised to use liquid glycerine - available from chemists. My transducer tube is a poor fit on the hull and the glycerine has to be topped up twice a season. The symptoms are poor sensitivity especially at very shallow depths.
I am on my third Nasa e/s. They have not lasted very long, but were relatively cheap to replace. Next time it will be a fish finder - a lot more information for not much more cash.

 

[Stemar]

NiCd rechargeables almost certainly won't have enough umph, as each cell only produces 1.2v, instead of 1.5 for non-rechargeables. Some of the more exotic (and expensive) rechargeables may be OK, though.

 

[DavidTocher]

Thanks to all for the advice. I do run the seafarer from the main battery and guessed that engine/dynamo noise was one of the problems. The tranducer is mounted through the hull and it works at full gain and seems insensitive. I'll hunt round for a new tranducer if they aren't too expensive.

 

[oldharry]

Good luck in finding a replacement transducer! Bear in mind that the transducers are 'tuned' to the output frequency of the echo sounder. The Seafarers worked at 150khz, while most modern ones (I think including Nasa) work at 200 khz. It is not possible to change them as the operating frequency is set by the way they are built.