In article ,
Larry wrote:

Me wrote in news:Me-A9B766.09450225112005
@netnews.att.net:

In article , Larry

wrote:

Then, there's the chance the old transducer is as worn out as its
electronics. They don't last forever, either.

--
Larry

Well now Larry, just what part of the Barium Titanate Crystal in
those transducers "WEARS OUT"? It either works or it doesn't, but
it isn't a "WEAR Item". Barium Titanate Crystals do not degrade over
time or use. They can fracture, but that happens only if overloaded,
or overpowered.


Me


Well, now, Me, the mount corrode. Marine growth eats into the
transparent dome, sometimes made of rubber, and makes it leak into the
"Barium Titanate Crystals". Constant contact with seawater eats
anything.....and should be replaced when the new sonar is installed WITH
the transducer it was TUNED WITH.

(Impressive about the name of the crystals, by the way...(c


If it is a Bronze Transducer Housing, you will corrode faster than
it will. If it is Epoxy, again, you will be long dead before it
will be. Most of the high end, Furuno Transducers are Expoxy
encapsulated, and designed to be mounted in Yard Provided Trunks.
The smaller ones are Bronze. 90% of the Barium Titanate Transducers
are built by the same OEM supplier for all the various sounder/fish
finder MFG's, so in all likelyhood your getting the same crystals
in most of the same power range transducers. Impedance of the
transducers will be very similar as they preety much all are using the
same Crystals. The only MFG, I ever saw that built their own
Transducers was Ross Labratories in Seattle, and they got their
substrate from the same OEM as everyone else. Ross Labs used a 100Khz
system, and designed their own Transudcers because they wanted control
over the beamwidth and cone pattern, as they built very specialized
Hydrological Survey sounders. There were a FEW, 28Khz Magnetic
Resrtiction Transducers used in the early 80's for the North Pacific
King Crab Fleet, but they really were a specialized unit, and were soon
replaced with a new epitaxial Barium Titanate Crystal Transducer in the
late 80's, because of the costs of MFG.

Me