Thank you. I could do this, but see my new thread. Also, I really
have no source of a "loaner" transducer.


On Thu, 13 Jul 2006 00:15:47 -0400, Larry wrote:

frank1492 wrote in
:

More than you wanted to know, but that's it. I'm suspicious that
the depth transducer itself is faulty, but what are your thoughts? And
if you think it is, how easy to replace?


Piezo crystals always have a kind of static DC voltage across them. It's
what makes the barbecue grill lighter arc when the hammer hits the piezo
crystal when you push the button.

This voltage can be measured with a digital voltmeter where that RCA
connector goes into the back of the sonar unit. Unplug the connector and
leave it hanging for a couple of hours, then measure the DC voltage with
your digital voltmeter. Little boat transducers don't produce much
voltage, but if it reads anything, the transducer is connected through
the wires which are not shorted or soaked in seawater, which will short
out the voltage. (If you just set a big transducer from one of our
submarine sonar arrays on a pallet unshorted, the voltage that
accumulates from sound noises hitting the big crystal is enough to put
you ON YOUR KNEES! Been there, felt that...(c

If you measure no voltage at all from the open crystal, switch to
resistance (ohms) and see what it reads. It should read infinity
(overrange on digital multimeters), not some low resistance or zero.

If it's not shorted or leaking down through some resistance but has no DC
voltage to measure from the noises under the hull, I'd probably say it's
DOOMED and to replace it, which usually means going into the yard as it
comes out the bottom.....sorry.

Another good checkout is to find someone else with your same sonar model!
Take the sonar head over and plug it into his sonar transducer. If it
still reads crap, the head is bad, not the transducer, obviously. If you
can borrow a loose head, drop it over the side so it's submerged then
plug it into your sonar unit. Same thing if it doesn't work...bad sonar,
not transducer.

Wow! I can't thank you guys enough. I have an appointment
to go to but will comment at length later.
I've never seen such a wealth of info amassed all in
one place!
Frank






On Thu, 13 Jul 2006 00:17:54 GMT, frank1492
wrote:

I now have full info on the depth finder that many of you requested
when initially trying to help me solve my problem.
The unit is a Datamarine LX201. With the input connected (RCA
plug) the display always reads 2 or 2.1 feet. (I checked to make sure
the plug was properly seated.) With the plug disconnected, the
display reads "MSD" and only a decimal point is shown. I assume
this is normal.
The transducer housings are located just forward of the engine.
The coax to the depth transducer (starboard side) appears to have no
splices. The speed transducer (paddle wheel) lies on the port side.
Both transducers show a housing that's about 2" in diameter and the
wires are molded in. (The speed transducer appears a little taller.)
Both appear to have screw threads and large "wing nuts" that are
marked "hand tight."
The coax from the speed transducer terminates in a coaxial
fitting in the instrument compartment, which means I could have
a speedometer if I wanted one.
More than you wanted to know, but that's it. I'm suspicious that
the depth transducer itself is faulty, but what are your thoughts? And
if you think it is, how easy to replace?
Your help is always very much appreciated!!
Frank

Frank - Does your thru-hull look like this?

http://www.dmimarine.com/DMIPIX/DMI%20THRU%20HULL.JPG

If so, DMI have dummy plugs for $10.00.

Their current transducers are $150.00 and have a screw cap instead of the
pin.

They are knowledgeable about the Datamarine units, so a call to them may
help.

The other company was SEA Inc, but they seem to have given up on Datamarine
repairs.


"frank1492" wrote in message
...
Wow! I can't thank you guys enough. I have an appointment
to go to but will comment at length later.
I've never seen such a wealth of info amassed all in
one place!
Frank






On Thu, 13 Jul 2006 00:17:54 GMT, frank1492
wrote:

I now have full info on the depth finder that many of you requested
when initially trying to help me solve my problem.
The unit is a Datamarine LX201. With the input connected (RCA
plug) the display always reads 2 or 2.1 feet. (I checked to make sure
the plug was properly seated.) With the plug disconnected, the
display reads "MSD" and only a decimal point is shown. I assume
this is normal.
The transducer housings are located just forward of the engine.
The coax to the depth transducer (starboard side) appears to have no
splices. The speed transducer (paddle wheel) lies on the port side.
Both transducers show a housing that's about 2" in diameter and the
wires are molded in. (The speed transducer appears a little taller.)
Both appear to have screw threads and large "wing nuts" that are
marked "hand tight."
The coax from the speed transducer terminates in a coaxial
fitting in the instrument compartment, which means I could have
a speedometer if I wanted one.
More than you wanted to know, but that's it. I'm suspicious that
the depth transducer itself is faulty, but what are your thoughts? And
if you think it is, how easy to replace?
Your help is always very much appreciated!!
Frank

Thanks GBM. Please see my new thread.







On Thu, 13 Jul 2006 09:37:50 -0400, "GBM"
wrote:

Frank - Does your thru-hull look like this?

http://www.dmimarine.com/DMIPIX/DMI%20THRU%20HULL.JPG

If so, DMI have dummy plugs for $10.00.

Their current transducers are $150.00 and have a screw cap instead of the
pin.

They are knowledgeable about the Datamarine units, so a call to them may
help.

The other company was SEA Inc, but they seem to have given up on Datamarine
repairs.


"frank1492" wrote in message
.. .
Wow! I can't thank you guys enough. I have an appointment
to go to but will comment at length later.
I've never seen such a wealth of info amassed all in
one place!
Frank






On Thu, 13 Jul 2006 00:17:54 GMT, frank1492
wrote:

I now have full info on the depth finder that many of you requested
when initially trying to help me solve my problem.
The unit is a Datamarine LX201. With the input connected (RCA
plug) the display always reads 2 or 2.1 feet. (I checked to make sure
the plug was properly seated.) With the plug disconnected, the
display reads "MSD" and only a decimal point is shown. I assume
this is normal.
The transducer housings are located just forward of the engine.
The coax to the depth transducer (starboard side) appears to have no
splices. The speed transducer (paddle wheel) lies on the port side.
Both transducers show a housing that's about 2" in diameter and the
wires are molded in. (The speed transducer appears a little taller.)
Both appear to have screw threads and large "wing nuts" that are
marked "hand tight."
The coax from the speed transducer terminates in a coaxial
fitting in the instrument compartment, which means I could have
a speedometer if I wanted one.
More than you wanted to know, but that's it. I'm suspicious that
the depth transducer itself is faulty, but what are your thoughts? And
if you think it is, how easy to replace?
Your help is always very much appreciated!!
Frank

On Thu, 13 Jul 2006 00:17:54 GMT, frank1492
wrote:

I now have full info on the depth finder that many of you requested
when initially trying to help me solve my problem.
The unit is a Datamarine LX201. With the input connected (RCA
plug) the display always reads 2 or 2.1 feet. (I checked to make sure
the plug was properly seated.) With the plug disconnected, the
display reads "MSD" and only a decimal point is shown. I assume
this is normal.
The transducer housings are located just forward of the engine.
The coax to the depth transducer (starboard side) appears to have no
splices. The speed transducer (paddle wheel) lies on the port side.
Both transducers show a housing that's about 2" in diameter and the
wires are molded in. (The speed transducer appears a little taller.)
Both appear to have screw threads and large "wing nuts" that are
marked "hand tight."
The coax from the speed transducer terminates in a coaxial
fitting in the instrument compartment, which means I could have
a speedometer if I wanted one.
More than you wanted to know, but that's it. I'm suspicious that
the depth transducer itself is faulty, but what are your thoughts? And
if you think it is, how easy to replace?
Your help is always very much appreciated!!
Frank


Here's the link to Datamarine http://www.sea-dmi.com/. The tarnsducer
is not painted over is it?

Yes it has been painted over many, many times. The guys at DMI
say that shouldn't matter much, and it hasn't for 10 years. Plus the
problem occurred suddenly near the end of last year's boating season.




On Thu, 13 Jul 2006 14:49:12 GMT, wrote:

On Thu, 13 Jul 2006 00:17:54 GMT, frank1492
wrote:

I now have full info on the depth finder that many of you requested
when initially trying to help me solve my problem.
The unit is a Datamarine LX201. With the input connected (RCA
plug) the display always reads 2 or 2.1 feet. (I checked to make sure
the plug was properly seated.) With the plug disconnected, the
display reads "MSD" and only a decimal point is shown. I assume
this is normal.
The transducer housings are located just forward of the engine.
The coax to the depth transducer (starboard side) appears to have no
splices. The speed transducer (paddle wheel) lies on the port side.
Both transducers show a housing that's about 2" in diameter and the
wires are molded in. (The speed transducer appears a little taller.)
Both appear to have screw threads and large "wing nuts" that are
marked "hand tight."
The coax from the speed transducer terminates in a coaxial
fitting in the instrument compartment, which means I could have
a speedometer if I wanted one.
More than you wanted to know, but that's it. I'm suspicious that
the depth transducer itself is faulty, but what are your thoughts? And
if you think it is, how easy to replace?
Your help is always very much appreciated!!
Frank


Here's the link to Datamarine http://www.sea-dmi.com/. The tarnsducer
is not painted over is it?

I do not know the unit you are having problems with but if you have the
manual check to see if the shallow depth sensitivity is adjustable.

Some units can be adjusted. If it too sensitive it can read the distance
from the transducer to the keel.


Alec



"frank1492" wrote in message
...
I now have full info on the depth finder that many of you requested
when initially trying to help me solve my problem.
The unit is a Datamarine LX201. With the input connected (RCA
plug) the display always reads 2 or 2.1 feet. (I checked to make sure
the plug was properly seated.) With the plug disconnected, the
display reads "MSD" and only a decimal point is shown. I assume
this is normal.
The transducer housings are located just forward of the engine.
The coax to the depth transducer (starboard side) appears to have no
splices. The speed transducer (paddle wheel) lies on the port side.
Both transducers show a housing that's about 2" in diameter and the
wires are molded in. (The speed transducer appears a little taller.)
Both appear to have screw threads and large "wing nuts" that are
marked "hand tight."
The coax from the speed transducer terminates in a coaxial
fitting in the instrument compartment, which means I could have
a speedometer if I wanted one.
More than you wanted to know, but that's it. I'm suspicious that
the depth transducer itself is faulty, but what are your thoughts? And
if you think it is, how easy to replace?
Your help is always very much appreciated!!
Frank