Depth sounder,

[Mr B]

I have just put a new Airmac depth sounder in, Depth and Temp, No speed wheel,
Not that the speed wheel worked all that well, As fast as I cleaned it, Things grew on it and stopped it working,

The old one was smashed and wires cut off,
I connected it up to the ST4000 GPS and speed and depth gauges,
To do this I cut the wire from the depth sounder,
It has 5 pins in the connector, 7 wires inside the cable,
I coloured coded five wires to the speed sensor and two wires to the depth sounder,
The depth sounder has 3 pins on the back of it, Colour coded, and one spade lug that has a silver colour but I have no wire for it,

Would it be wise to join the bare silver wire on the speed gauge across to the silver spade lug on the depth gauge or just leave it bare,

The boat is precisely 3 feet off the ground under the Sensor in the thru hull,
The boat is on the hard,
Does the boat need to be back in the water to recalibrate it, or will it recalibrate itself when back in the water,
Its shows 14 feet depth, Which I cant change, Maybe Im doing it wrong,

Thanks in advance,
Brian,

[billknny]

Some sounders can get a signal through air, and some can not.

Remember... the variable here is the speed of sound. It is (roughly) 4.5 times faster in saltwater than in air, so showing 14 feet in air instead of 3 feet actual is real close to the right answer.