I am about to purchase a depth sounder to replace the old one[s]. I
have two transponders in the bottom. One at 50hz from a Furuno/Kobel
and another 200hz (???) that belonged to a Gemtronics. What are the
chances that they will work with a new sender/display unit.

"capt-dia" wrote in
oups.com:

What are the
chances that they will work with a new sender/display unit.


About nil. A 200 Khz transducer isn't on 200 Khz...it's near 200 Khz,
nearer than 50 Khz, so they call it a 200 Khz. The impedances are also
difference, the resistance they offer the transmitter. The transmitters
and receivers are tuned at the factory to that particular transducer the
manufacturer uses. They're not universal.

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

--
Larry

"capt-dia" wrote in message
oups.com...
I am about to purchase a depth sounder to replace the old one[s]. I
have two transponders in the bottom. One at 50hz from a Furuno/Kobel
and another 200hz (???) that belonged to a Gemtronics. What are the
chances that they will work with a new sender/display unit.

Making a couple of assumptions here, one that the two transducers in
your hull are still in good shape, and the second that you are not trying to
run more power to those transducers than they are capable of handling, then
chances are pretty good that they will operate fairly well.
Just how well will depend on the transducer matching network on the new
machine and the type of transducer cable on the old transducers. Cables with
a shielded, twisted pair of wires will adapt to many current machines (200
or 50 Khz, of course) but if the cable is a simple coax cable the matching
is not so likely.
While in the "business" for many years, we always advised the new
machine owner to be sure and anticipate transducer changes may be necessary,
but it is worth a try to use the old transducer. The Konel/Furuno
transducers were normally pretty high quality, and stand a small chance of
performing better than the transducer provided with the new machine.
Bottom line: It's sure worth a try!

Old Chief Lynn...... been there, done that.

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

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

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

On a previous boat I had one of these old sounder that rotated and
flashed a little neon light. An antique. I replaced it with a new
digital Standard Horizon sounder. Everybody said it would not work
with the old transducer. I figured what the hell do I have to lose. I
plugged it in, it worked great . I still see the boat regularily at
the marina. It's still working 8 years later

Jeannette

.. On 24 Nov 2005 11:21:07 -0800, "capt-dia"
wrote:

I am about to purchase a depth sounder to replace the old one[s]. I
have two transponders in the bottom. One at 50hz from a Furuno/Kobel
and another 200hz (???) that belonged to a Gemtronics. What are the
chances that they will work with a new sender/display unit.

"Lynn Coffelt" wrote in message
...

"capt-dia" wrote in message
oups.com...
I am about to purchase a depth sounder to replace the old one[s]. I
have two transponders in the bottom. One at 50hz from a Furuno/Kobel
and another 200hz (???) that belonged to a Gemtronics. What are the
chances that they will work with a new sender/display unit.

Making a couple of assumptions here, one that the two transducers in
your hull are still in good shape, and the second that you are not trying
to
run more power to those transducers than they are capable of handling,
then
chances are pretty good that they will operate fairly well.
Just how well will depend on the transducer matching network on the
new
machine and the type of transducer cable on the old transducers. Cables
with
a shielded, twisted pair of wires will adapt to many current machines (200
or 50 Khz, of course) but if the cable is a simple coax cable the matching
is not so likely.
While in the "business" for many years, we always advised the new
machine owner to be sure and anticipate transducer changes may be
necessary,
but it is worth a try to use the old transducer. The Konel/Furuno
transducers were normally pretty high quality, and stand a small chance of
performing better than the transducer provided with the new machine.
Bottom line: It's sure worth a try!

Old Chief Lynn...... been there, done that.


Well said Lynn.
AirMar makes most of the transducers and they put out a nice cross reference
book.
I see the same basic transducer marketed with different connectors/pin outs.
As long as the frequency range is the same and power level is not exceeded.
most transducers can be rewired to work with a different unit. Its when you
get into temperature and speed sensors that things get a bit tricky. Once
again, go to the cross reference book, look at the schematic of the
transducerducer and the cable. Those with a duplexer in the transducer
probably won't work well or at all with a unit designed for seperate cable
wires.
I only know of a few units that allow the operator/maintenance technician to
tweak the frequency to match the transducer. Furuno has this "sweet spot"
tweaking on a few of their units.

Doug K7ABX