In article ,
"RB" wrote:

Just found a couple of old transducers tucked away in a desk drawer in my
workshop. No clue as to what they're from, make, model, etc, nor as to
operating frequency.

If I recall correctly, the freq is the most important characteristic. Also
seems like the other thing is not to stick 'em on some depth finder that
overpowers them and pops the circuit that fixes the freq. Is all this
correct?

If so, what's some practical, reasonably simple way to determine their
design freq?



Most of the Professionals would use a Signal Generator, Scope, and
Impedance Bridge, and then sweep the transducer to determine its
design frequency. Shoudn't be to hard if you got the test equipment.

Bruce in alaska
--
add a 2 before @

My situation is a little different. I've got a boat built around 1960, it's
got a thru-hull transducer with no markings. Presumably it's a little more
modern than 1960's!
Assuming that I can estimate the resonant frequency ( I've got only a
frequency generator and a decent multimeter, ) how do I decide if it's worth
while getting a plug to adapt the transmitter to my Lowrance X48?

Or do I just wait a year until I pull the boat out of the water for annual
maintenance and fit a new thru-hull transponder?
Regards
David
"Bruce in Alaska" wrote in message
...
In article ,
"RB" wrote:

Just found a couple of old transducers tucked away in a desk drawer in
my
workshop. No clue as to what they're from, make, model, etc, nor as to
operating frequency.

If I recall correctly, the freq is the most important characteristic.
Also
seems like the other thing is not to stick 'em on some depth finder that
overpowers them and pops the circuit that fixes the freq. Is all this
correct?

If so, what's some practical, reasonably simple way to determine their
design freq?



Most of the Professionals would use a Signal Generator, Scope, and
Impedance Bridge, and then sweep the transducer to determine its
design frequency. Shoudn't be to hard if you got the test equipment.

Bruce in alaska
--
add a 2 before @

On Wed, 14 Jan 2004 21:55:45 +1100, David Flew wrote:

My situation is a little different. I've got a boat built around 1960, it's
got a thru-hull transducer with no markings. Presumably it's a little more
modern than 1960's!
Assuming that I can estimate the resonant frequency ( I've got only a
frequency generator and a decent multimeter, ) how do I decide if it's worth
while getting a plug to adapt the transmitter to my Lowrance X48?

Or do I just wait a year until I pull the boat out of the water for annual
maintenance and fit a new thru-hull transponder?
Regards
David

I'd suggest you wait until you pull the boat out of the water and replace
it. The problem is that you can't identify it. Others have suggested ways
to determine the resonant frequency, but that won't tell you how much peak
power it will handle. I don't know how you can do that without destroying
it.
--

Larry
email is rapp at lmr dot com

In article ,
Larry wrote:



I'd suggest you wait until you pull the boat out of the water and replace
it. The problem is that you can't identify it. Others have suggested ways
to determine the resonant frequency, but that won't tell you how much peak
power it will handle. I don't know how you can do that without destroying
it.

If one can determine the Resonate Frequency of the transducer, then it
would make sense to go ahead and hook up the sounder head. If it blows
the tranducer your not really out anything since it would have to be
replaced anyway, during the next haulout. If it works you save yourself
a haulout, and have a working sounder now.

Bruce in alaska
--
add a 2 before @

Hey! Great discussions. Thanks for the thoughtful inputs.

}}} Others have suggested ways
to determine the resonant frequency, but that won't tell you how much peak
power it will handle. I don't know how you can do that without destroying
it. {{{

Guess and go by weight is the only clue I'd have on these unmarked ones.

}}} If one can determine the Resonate Frequency of the transducer, then it
would make sense to go ahead and hook up the
sounder head. If it blows
the tranducer your not really out anything since it would have to be
replaced anyway, during the next haulout. {{{

Right on. Nothing to lose, really. Maybe something gained.

On Wed, 14 Jan 2004 23:37:15 -0600, RB wrote:

Hey! Great discussions. Thanks for the thoughtful inputs.

}}} Others have suggested ways
to determine the resonant frequency, but that won't tell you how much peak
power it will handle. I don't know how you can do that without destroying
it. {{{

Guess and go by weight is the only clue I'd have on these unmarked ones.

}}} If one can determine the Resonate Frequency of the transducer, then it
would make sense to go ahead and hook up the
sounder head. If it blows
the tranducer your not really out anything since it would have to be
replaced anyway, during the next haulout. {{{

Right on. Nothing to lose, really. Maybe something gained.

Just a guess, but if the impedance is mis-matched, you could blow out the
output stage of the unit. I'd be careful.
--

Larry
email is rapp at lmr dot com

Larry,

I don't believe the power rating would be tied to the failure level.
More than likely it is tide to the temperature rise in a specified
ambient.

If I were working with such a device on the bench, I would monitor temp
so it did not exceed a reasonable rise.

Regards, Ron

I don't recieve e-mail at this address because of spam. E-mail me
at crtsrATmsnDOTcom.