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