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

I'm guessing Datamarine is out of business, but
depth replacement cores are found at
http://www.ess-kayyards.com/catalog/page11.html
Could this be what I need?




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

I noticed that the site I just mentioned sells O-rings for the
Datamarine transducer. I think that is what I may have seen
protruding out around the base of the transducer housing.
Couldn't tell what it was at first, but certainly if that's what it
was, bilge water could get in. Am I on to something? And
what would cause an O-ring to pop out of place or stretch
like that?






On Thu, 13 Jul 2006 00:27:44 GMT, frank1492
wrote:

I'm guessing Datamarine is out of business, but
depth replacement cores are found at
http://www.ess-kayyards.com/catalog/page11.html
Could this be what I need?




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 00:33:57 GMT, frank1492
wrote:

I noticed that the site I just mentioned sells O-rings for the
Datamarine transducer. I think that is what I may have seen
protruding out around the base of the transducer housing.
Couldn't tell what it was at first, but certainly if that's what it
was, bilge water could get in. Am I on to something? And
what would cause an O-ring to pop out of place or stretch
like that?

If you undo the "wing nut" you mentioned, you should be able to pull
the transducer out of the through-hull housing (have a rag handy to
stuff in the resulting hole!)(If you do this, you will get a large
water fountain - just stuff the rag into the through-hull fitting -
the water pressure will be very low.)

The "O-rings" you mentioned will go on the transducer, to prevent
water from entering between the transducer and housing. The rubber
thing you see against the hull is just a rubber washer (or more likely
excess sealant).



--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

If you have read all my messages, would you agree that the
transducer itself is likely the cause of the problem? If something
else is likely (or possible) I need to be careful because the
transducer will cost about $170.
Are you saying that when I pull the transducer out, the
hole will go all the way through? Seems pretty risky with the
boat in the water. I assumed that it would be like a chamber
with the bottom sealed off so that I would just drop the
transducer in with no "fountain."
Thank you very much for your help!!
Frank



On Wed, 12 Jul 2006 18:32:21 -0700, Peter Bennett
wrote:

On Thu, 13 Jul 2006 00:33:57 GMT, frank1492
wrote:

I noticed that the site I just mentioned sells O-rings for the
Datamarine transducer. I think that is what I may have seen
protruding out around the base of the transducer housing.
Couldn't tell what it was at first, but certainly if that's what it
was, bilge water could get in. Am I on to something? And
what would cause an O-ring to pop out of place or stretch
like that?

If you undo the "wing nut" you mentioned, you should be able to pull
the transducer out of the through-hull housing (have a rag handy to
stuff in the resulting hole!)(If you do this, you will get a large
water fountain - just stuff the rag into the through-hull fitting -
the water pressure will be very low.)

The "O-rings" you mentioned will go on the transducer, to prevent
water from entering between the transducer and housing. The rubber
thing you see against the hull is just a rubber washer (or more likely
excess sealant).

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.

A couple of things frank:

- datamarine may be out of business, but there are two companies that sell
parts. One is dmi marine at www.dmimarine.com - the other, I forget, but a
google search should bring them up - I think they are both in the same town
in Mass - Pocasset?

- If you get a reading, it may be that something is interfering with the
transducer - It should not have any anti-fouling paint on it. There should
also be nothing else like say part of the hull or engine that could cause an
echo - the beam has quite a wide angle - forget the number but probably
about 30 degrees.

- Stupid questions, but do you have more than 2.1 ft below the transducer
when docked!

BTW, don't worry about pulling the transducer (if it is of the retractable
type). It would be best to have a plug that you can use to stop the water
coming in - Most units were supplied with blank plugs when new, but a rag or
tapered softwood plug would suffice for a short period. A spare set of hand
s may help. Try cleaning the unit and dropping it over the side to see if
you can get a different reading.

BUT, I have a Datamarine depthsounder myself (different model), and the
transducer cannot be pulled - It is permanently installed - If it is
removable, there should be two nuts - one that holds the thruhull in an done
at the top that holds the xducer into the thruhull.

Finally - You can buy a complete new depthsounder with a transom mount for
less than $169, so shop around!

Good Luck!


"frank1492" wrote in message
...
If you have read all my messages, would you agree that the
transducer itself is likely the cause of the problem? If something
else is likely (or possible) I need to be careful because the
transducer will cost about $170.
Are you saying that when I pull the transducer out, the
hole will go all the way through? Seems pretty risky with the
boat in the water. I assumed that it would be like a chamber
with the bottom sealed off so that I would just drop the
transducer in with no "fountain."
Thank you very much for your help!!
Frank

On Thu, 13 Jul 2006 02:08:11 GMT, frank1492
wrote:

If you have read all my messages, would you agree that the
transducer itself is likely the cause of the problem? If something
else is likely (or possible) I need to be careful because the
transducer will cost about $170.

I suspect that the transducer is the most likely problem, if there are
no obvious problems with the wiring or connectors. Best way to check
would be to borrow a transducer from a dealer, and try jut hanging it
over the side of the boat.

Are you saying that when I pull the transducer out, the
hole will go all the way through? Seems pretty risky with the
boat in the water. I assumed that it would be like a chamber
with the bottom sealed off so that I would just drop the
transducer in with no "fountain."
Thank you very much for your help!!
Frank

The speedo transducer will certainly pull out, and leave a big hole,
because you occasionally (often?) need to pull it to evict the marine
beasties that settle around the paddlewheel. If I recall correctly,
the depth sounder transducers I had on previous boats were one piece -
the through-hull fitting was part of the transducer, so the transducer
could not be pulled out. (but other makes may be different)


--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

frank1492 wrote:
If you have read all my messages, would you agree that the
transducer itself is likely the cause of the problem? If something
else is likely (or possible) I need to be careful because the
transducer will cost about $170.
Are you saying that when I pull the transducer out, the
hole will go all the way through? Seems pretty risky with the
boat in the water. I assumed that it would be like a chamber
with the bottom sealed off so that I would just drop the
transducer in with no "fountain."

From the link you posted:

http://www.ess-kayyards.com/catalog/page11.html

Look at the item:

Datamarine Depth Replacement Core $129.99
Replacement core for Datamarine Depth Sounder. For transducer models
S200DL, LX201, Link 5100/6100 and All Dart models.

That is a removable transducer. It slides down into a through hull
fitting that looks sort of like a top hat.

When the transducer is slid down into the through hull fitting, the
flange on the top of it stops it in the fully inserted position (flush
with the fitting on the "wet side" outside of the hull). It will
usually have an small key that matches a notch in the top of the through
hull for fore and aft alignment too.

Then, typically, there is another threaded collar (the transducer cable
runs through that collar) that screws down onto the top of the through
hull and that traps the transducer in place. If there is not a threaded
collar, there may be a SS clevis pin that goes through the through hull
fitting and the transducer body to keep it in place.

If that is a plastic or nylon through hull fitting, the warning about
hand tightening refers to the nut that holds the through hull fitting in
the boat and it may also be referring to a collar that keep the
transducer in place. Those are plastic or nylon, if you go after them
with a pipe wrench or water pump pliers you will run the risk of
breaking them from over tightening. If it breaks and the through hull
fitting or transducer pops out, you will have a 2" hole in your hull
below the waterline.

I would remove the retaining collar or pull the clevis pin (keeping a
hand on the transducer) and then try to raise it up a little. It will
normally be keyed to the through hull for fore and aft alignment and
cannot be rotated in the through hull until it has been raised up a
little.

If it seems to want to come out, stifle the terror in your heart, get
your rag ready, slide the transducer up, and plug the hole with the rag.
A quart or two of water down there won't hurt anything and can be
refreshing on a hot day.

If you look through the stuff that came with the boat, you may find a
plastic plug that looks like the transducer body. It may be for the
speed impeller so make sure it fits before you count on it being used to
plug the depth transducer fitting.

If you have to leave the rag in place for a day or two, drape another
rag over it down around the through hull fitting, and tie it in place
snugly with piece of line or use a radiator clamp gently so as to not
damage the threads or through hull fitting.

Use silicone O-ring lube (Lowes or Home Depot, where the home water
filters are usually) on the O-rings and outside of the transducer body
and it will always be easy to remove.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

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