For some years now I have a Zercom 165 fishfinder. At the time I
bought this particular unit because it was supposed to have a good
performance at high speeds. With the unit came a transom mount
transducer. So far I had poor results with it. It performs very wel at
low speeds but as soon as a come on a plane the reading gets flaky and
at a a speed of 25 knots or more I get no readout at all. I already
tried relocating the transducer, trying to find a spot with less
turbulence, but with little or no improvement.

Now I'm considering moving it to the inside of the boat. I suppose I
could mount it in the bildge, fixing it with some epoxy or sillicone.
Is there anyone out there who had similar experience or who could give
me some pointers in order to solve this problem ?

Many thanks in advance

Alex

1) No matter what manufacturers say, there are some boats on which it is
seemingly impossible to find a location where the transducer will be happy
at high speeds. The question really is how many holes do you want to drill
in your boat for the sake of experiment? On mine, I used some existing holes
to attach a piece of scrap wood. I drilled a million holes in that while
experimenting with location, and then used it as a template for the final
holes. Even so, above a certain speed I get an accurate depth reading, but
the thing doesn't see fish.

2) Inside mounting: You need a totally different transducer for that, and if
Zercom is like Garmin (the brand I bought), an inside transducer will only
work in a fiberglass boat.

Back to #1: Find someplace on your transom to attach some wood temporarily,
and build some sort of jig that allows you to move the transducer around.
Don't forget that distance from the prop(s) isn't the only factor. The depth
of the transducer matters, too.


"alex" wrote in message
...

For some years now I have a Zercom 165 fishfinder. At the time I
bought this particular unit because it was supposed to have a good
performance at high speeds. With the unit came a transom mount
transducer. So far I had poor results with it. It performs very wel at
low speeds but as soon as a come on a plane the reading gets flaky and
at a a speed of 25 knots or more I get no readout at all. I already
tried relocating the transducer, trying to find a spot with less
turbulence, but with little or no improvement.

Now I'm considering moving it to the inside of the boat. I suppose I
could mount it in the bildge, fixing it with some epoxy or sillicone.
Is there anyone out there who had similar experience or who could give
me some pointers in order to solve this problem ?

Many thanks in advance

Alex

On Wed, 17 Sep 2003 20:05:56 GMT, (alex) wrote:


For some years now I have a Zercom 165 fishfinder. At the time I
bought this particular unit because it was supposed to have a good
performance at high speeds. With the unit came a transom mount
transducer. So far I had poor results with it. It performs very wel at
low speeds but as soon as a come on a plane the reading gets flaky and
at a a speed of 25 knots or more I get no readout at all. I already
tried relocating the transducer, trying to find a spot with less
turbulence, but with little or no improvement.

Now I'm considering moving it to the inside of the boat. I suppose I
could mount it in the bildge, fixing it with some epoxy or sillicone.
Is there anyone out there who had similar experience or who could give
me some pointers in order to solve this problem ?

Many thanks in advance

Alex


Hi Alex.

As Doug pointed out, placement is critical for both "stern mounted"
and "through the hull" transducers. Any turbulence or "bubbles" in
the water flow around the transducer will cause problems. Usually, a
transom mount is placed near the first "hull step", away from the
prop. It should also be mounted roughly "even" with the hull
(depth-wise") to 1/2" below.

If you look up (google) fish-finders, you should find some good pages
( I did it not too long ago, but didn't keep the url's).

There are various ways to mount the transducer inside (through the
hull), but *don't* use silicone. It will kill the signal. Epoxy (for
fiberglass) and "water boxes" for aluminum, are preferred.

Good luck,
noah

I think it takes just plane good luck to get a sounder that works well at
speed. My Garmin does a better job than my Humminbirds, but it still shows
a lot of noise at speed.

I also have an eagle, but its on the trolling motor of my old boat so I
don't know how it works at speed.


--
Bob La Londe
Yuma, Az
http://www.YumaBassMan.com

"alex" wrote in message
...

For some years now I have a Zercom 165 fishfinder. At the time I
bought this particular unit because it was supposed to have a good
performance at high speeds. With the unit came a transom mount
transducer. So far I had poor results with it. It performs very wel at
low speeds but as soon as a come on a plane the reading gets flaky and
at a a speed of 25 knots or more I get no readout at all. I already
tried relocating the transducer, trying to find a spot with less
turbulence, but with little or no improvement.

Now I'm considering moving it to the inside of the boat. I suppose I
could mount it in the bildge, fixing it with some epoxy or sillicone.
Is there anyone out there who had similar experience or who could give
me some pointers in order to solve this problem ?

Many thanks in advance

Alex

I have a Lowrance on my Lund. Works pretty well up to 30+ MPH.
Transducer on transom.
I think it takes some fooling around with location, depth, angle.

del cecchi

"Bob La Londe" wrote in message
...
I think it takes just plane good luck to get a sounder that works well
at
speed. My Garmin does a better job than my Humminbirds, but it still
shows
a lot of noise at speed.

I also have an eagle, but its on the trolling motor of my old boat so
I
don't know how it works at speed.


--
Bob La Londe
Yuma, Az
http://www.YumaBassMan.com

"alex" wrote in message
...

For some years now I have a Zercom 165 fishfinder. At the time I
bought this particular unit because it was supposed to have a good
performance at high speeds. With the unit came a transom mount
transducer. So far I had poor results with it. It performs very wel
at
low speeds but as soon as a come on a plane the reading gets flaky
and
at a a speed of 25 knots or more I get no readout at all. I already
tried relocating the transducer, trying to find a spot with less
turbulence, but with little or no improvement.

Now I'm considering moving it to the inside of the boat. I suppose I
could mount it in the bildge, fixing it with some epoxy or
sillicone.
Is there anyone out there who had similar experience or who could
give
me some pointers in order to solve this problem ?

Many thanks in advance

Alex

On Wed, 17 Sep 2003 21:07:21 GMT, "Doug Kanter"
wrote:

1) No matter what manufacturers say, there are some boats on which it is
seemingly impossible to find a location where the transducer will be happy
at high speeds. The question really is how many holes do you want to drill
in your boat for the sake of experiment? On mine, I used some existing holes
to attach a piece of scrap wood. I drilled a million holes in that while
experimenting with location, and then used it as a template for the final
holes. Even so, above a certain speed I get an accurate depth reading, but
the thing doesn't see fish.

2) Inside mounting: You need a totally different transducer for that, and if
Zercom is like Garmin (the brand I bought), an inside transducer will only
work in a fiberglass boat.

Back to #1: Find someplace on your transom to attach some wood temporarily,
and build some sort of jig that allows you to move the transducer around.
Don't forget that distance from the prop(s) isn't the only factor. The depth
of the transducer matters, too.



The dealer actually advised me to mount it inside the hull (it is an
fiberglass boat). But then again, he advised me also some other things
which didn't work.

The boat is an deep-V. I cannot mount it on the side because of the
trim plates. I do have a couple of questions:
How far should the puck stick out below the bottom ?
Should the the puck be straight (parallel with the bottom) or should
it be mounted at a slight angle ?

I really appriciate your input, this issue seems to be one of these
things which rely more on experience and experiment than on exact
sience.

"alex" wrote in message
...


The dealer actually advised me to mount it inside the hull (it is an
fiberglass boat). But then again, he advised me also some other things
which didn't work.

Again, my only experience is with the Garmin brand, which requires a totally
different transducer for in-hull mounting. You need to contact your
manufacturer about your particular unit.


The boat is an deep-V. I cannot mount it on the side because of the
trim plates. I do have a couple of questions:
How far should the puck stick out below the bottom ?
Should the the puck be straight (parallel with the bottom) or should
it be mounted at a slight angle ?

Mine said it should be mounted so the bottom face of the transducer was at
REAL level, or, in other words, parallel to the surface of the water, and
protruding 1/4" below the surface. If I'm alone in the boat, it's going to
end up lower because it's a small boat with all the weight in the back. If
my son's in the boat, his weight levels the boat nicely and the fishfinder
performs quite a bit better at high speeds.

What does your instruction book say about all this?

"Doug Kanter" wrote in message
...
"alex" wrote in message
...


The dealer actually advised me to mount it inside the hull (it is an
fiberglass boat). But then again, he advised me also some other
things
which didn't work.

Again, my only experience is with the Garmin brand, which requires a
totally
different transducer for in-hull mounting. You need to contact your
manufacturer about your particular unit.


The boat is an deep-V. I cannot mount it on the side because of the
trim plates. I do have a couple of questions:
How far should the puck stick out below the bottom ?
Should the the puck be straight (parallel with the bottom) or should
it be mounted at a slight angle ?

Mine said it should be mounted so the bottom face of the transducer
was at
REAL level, or, in other words, parallel to the surface of the water,
and
protruding 1/4" below the surface. If I'm alone in the boat, it's
going to
end up lower because it's a small boat with all the weight in the
back. If
my son's in the boat, his weight levels the boat nicely and the
fishfinder
performs quite a bit better at high speeds.

What does your instruction book say about all this?

I think most fiberglass boats mount the transducer in the bilge, unless
there is foam core down there. It needs solid glass to shoot through.
Do the trim tabs go all the way to the chines? is this a pad-vee?

The tabs could be part of the problem, causing turbulence near the
transducer.

del cecchi

I have a 19' Regal which has what they call a FasTrac hull. This hull has a
step that is roughly in the center separating the front and rear halves of
the boat. This is designed to funnel air under the hull and reduce drag
providing more power/fuel efficiency with less power. I have the same
problem with my depth finder at 10+ mph. I have tried filling my bilge with
water and putting it in there and it does seem to work off and on. I'm going
to take the chance and epoxy it in. Hopefully everything goes well and I get
a decent signal. I boat mostly in Tampa Bay and have found myself too
shallow on several outings.


"noah" wrote in message
...
On Wed, 17 Sep 2003 20:05:56 GMT, (alex) wrote:


For some years now I have a Zercom 165 fishfinder. At the time I
bought this particular unit because it was supposed to have a good
performance at high speeds. With the unit came a transom mount
transducer. So far I had poor results with it. It performs very wel at
low speeds but as soon as a come on a plane the reading gets flaky and
at a a speed of 25 knots or more I get no readout at all. I already
tried relocating the transducer, trying to find a spot with less
turbulence, but with little or no improvement.

Now I'm considering moving it to the inside of the boat. I suppose I
could mount it in the bildge, fixing it with some epoxy or sillicone.
Is there anyone out there who had similar experience or who could give
me some pointers in order to solve this problem ?

Many thanks in advance

Alex


Hi Alex.

As Doug pointed out, placement is critical for both "stern mounted"
and "through the hull" transducers. Any turbulence or "bubbles" in
the water flow around the transducer will cause problems. Usually, a
transom mount is placed near the first "hull step", away from the
prop. It should also be mounted roughly "even" with the hull
(depth-wise") to 1/2" below.

If you look up (google) fish-finders, you should find some good pages
( I did it not too long ago, but didn't keep the url's).

There are various ways to mount the transducer inside (through the
hull), but *don't* use silicone. It will kill the signal. Epoxy (for
fiberglass) and "water boxes" for aluminum, are preferred.

Good luck,
noah

On Fri, 26 Sep 2003 22:51:54 GMT, "John"
wrote:

I have a 19' Regal which has what they call a FasTrac hull. This hull has a
step that is roughly in the center separating the front and rear halves of
the boat. This is designed to funnel air under the hull and reduce drag
providing more power/fuel efficiency with less power. I have the same
problem with my depth finder at 10+ mph. I have tried filling my bilge with
water and putting it in there and it does seem to work off and on. I'm going
to take the chance and epoxy it in. Hopefully everything goes well and I get
a decent signal. I boat mostly in Tampa Bay and have found myself too
shallow on several outings.



John, if you are able to access it, I would try to epoxy the
transducer forward, just ahead of the step. The step will create
turbulence at low speed, and at planing speed, much of the aft portion
will be out of the water.
Good luck.
....carry on.
noah

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