Depth Sounder Works?!

[rickpyne]

Dear Forum Members
I have an unusual question ....my boat is out of the water and I have an old Raymarine depth sounder system, can , if I turn my instruments on , I get a DEPTH SOUNDING?? Remember the boat is out of the water. If yes can I then adjust my sounder to an accurate reading.....

Thanks in advance Rick

[Wotname]

No, at least nothing accurate IIRC.

[GordMay]

Greetings and welcome aboard the CF, Rick.
No.

[a64pilot]

Needs water to transmit the signal, but it won’t hurt it turn it on to try.

Silly as this sounds, I calibrated mine by slowly running aground at a speed that I knew I could back off.

I guess a more intelligent person could measure the depth from the waterline to the xducer and then program that number as the offset, but I ran aground instead

[carlosproa]

Are you trying to determine if the sounder works?
Depending on how much clearance from the ground, you could build a column of water using a bucket and a trash bag that has two openings, one for the hose and one for air to scape and later water as you want continuous flow. The rim of the trashbag can use flexible material to temporarily adhere to the hull hugging above the transducer to ensure complete immersion

Or

Just buy a new transducer and take that variable out of your doubts

[Pete7]

Originally Posted by Wotname

No, at least nothing accurate IIRC.

Agreed, but whilst the boat is out of the water:

A. Check your actual keel depth, not what the manufacturer advertised, but your now when you have had to raise the waterline to deal with all the stuff on board we all consider essential.

B. Measure the transducer to keel bottom.

C. Measure the transducer to existing waterline.

Then when the boat is next in the water you can adjust it to what you want, either absolute depth of water from the surface, or under the transducer, or under the keel.

Ours is set at under the transducer for no particular reason other than that's what we started with, but know that we can just float in 1 metre, a nice round number on the ST60 display.

[gonesail]

easiest way to calibrate is at the slip. use a lead line to check and go from there. i want the instrument to show the depth from the waterline.

[GordMay]

A quick way to check if the transmitter stage & transducer are working at all is to feel the face of the transducer, with the sounder running, you should be able to feel the pulses, or hear the transducer ticking.
The Amplitude Modulated (AM radio) carrier frequencies are in the frequency range 535 - 1605 kHz (10kHz intervals), and FM radio is in the MHz range; whereas depth sounders generally operate at either 50kHz or 200kHz. Accordingly, a radio is unlikely to detect your sounder (as static); though I’ve seen it suggested that they may < https://www.cruisersforum.com/forums...tml#post185510 >.

FWIW: Raytheon ST-60 Digital Instruments SERVICE Manual (VERY Rare)
➥ http://www.olajedatos.com/documentos...e%20Manual.pdf

Some earlier CF discussion:
➥ https://www.cruisersforum.com/forums...er-183918.html
➥ https://www.cruisersforum.com/forums...ng-218657.html
➥ https://www.cruisersforum.com/forums...oting-775.html

[a64pilot]

Gord thanks for the ST60 link.

As a diver some depth sounders annoy me, most don’t. Some you feel in the back of your head as opposed to hearing it, it sounds like a spark plug snapping, an arc type of sound.
I have no idea why some you don’t hear and some are quite loud?
Most all Sounders are either 50 Hz or 200 Hz, at least our small non pro ones.

Then of course there are CHIRP sounders now, and I’ve not noticed any sound from them.

[dfelsent]

Thanks for the service manual link!
The microprocessor data sheet is here:
https://www.renesas.com/sg/en/doc/Do...5EJ4V1UM00.pdf
It’s useful for understanding the temperature sensor adc reference voltage.