"Lloyd Sumpter" wrote in message .. .
Hi,

I still have the thru-hull from a long-dead knotmeter in Far Cove. I
may be able to dig up the partially-working paddle-wheel sender (iirc
needs a new paddlewheel).

Can I get a new sender, with proper documentation so I know how it
works, and hook it into my laptop? The Signet sender appears to put out a
voltage more-or-less proportional to speed, correct? So I would need a bit
of electronics (buffer/amp? and A/D) to put the value into the parallel
port of the laptop. Then a few runs with a GPS in still water should allow
me to calibrate it.

Where can I get data on what these senders actually put out?

Take a powered up down to the local auto dealer and see if they will
let you hook it up to the occilliscope, assuming the guys there know
how to do something other than hook up the probes and run a "self
test" on the car. You will be able to see if it is digital or analog,
and how much current it generates, how it sends the information to the
cpu, etc...
Scotty

Lloyd Sumpter
"Far Cove" Catalina 36 - waiting for new engine