Hi Folks

Thanks gents for the great information. Yes Roger I can do a comparison but
not for a few months, here both Great Lakes near me are frozen over and that
process will not be that easy. Doable but not easy.

I was hoping to read a response like " yes, cut away and your existing
tranducer and new head are compatible so splicing wont matter much at
200khz." I didn't read that statement through all the technical and
obvious and accurate and helpful information. I didn't read that at all. So
for piece of mind I might have to simply install the new tranducer with
extension cable where all plug ends meet female to male properly and
according to manufacture's (and salesmen) recommendations. Which is 100%
guarantee It will work correctly.

Our lakes are no where near the 800 feet depths that these transducers are
good to. If you want better tranducers for a ocean use or sea use then you
can buy the better tranducers, but Lake Erie might be 80 or 90 feet at max
and Lake Ontario might be approx 150 feet. I was in Deep River before, that
was about 700 feet.

I will re-read all this wealth of information again and study it much closer
and both learn and decide. Thank you all for the wealth of information to
make my decision. I am most greatful for that. But I didn't see a statement
like mentioned above so it is obviously something more technical and
critical that it is done right. And any Marina around here would simply
install new.

So if I cannot simply splice and go (about 1 or 2 hours costs) then I will
buy new (about $300.00 plus day's work). But I know that existing transducer
is good quality because it replaced a less quality one a few years back, but
I was hoping there was a way I could identify if it were 200khz to be
compatible with the new head. Then I could splice. Or find an adapter plug
to fit, maybe Lowrance sells that.

O well, I still have a couple months before the pickerel are in this end of
the lake so I or WE will resolve this. And we will do it right. Hopefully
not duplicating any work unecessary by installing a lower quality new part
where there is already an exisiting good quality part. Because that is
exactly what a local Marina would do. Not one, not a single one Marina
around here would understand a word of your technical postings here. Just
list price and retail price of the new Lowrance Product and delivery times
and install times multiplied by hourly rate.

While I am a Ham, licenced and active, I am an appliance operator and I
understand basic theory I don't understand the quantum mechanics of it.
Although I can send and receive code at 20 WPM without the help of a
computer or decoder.

73s again and thanks again gents,

Cheers






"Roger Hayter" wrote in message
...
Tom wrote:

Thank you gents for the discussion.

Yes, I talked to Lowrance and of course they have a $200.00 (new
tranducer
with longer coax) and my installation time is about a day's work. Of
course
when you start pulling off panels of a 40 year old boat with flybridge
you
will find another day's work.

I don't have a scope but I have a digital volt/ohm meter. I was hoping
there
was a method of testing the existing transducer for compatibility.

The plug's ends do not match (male -- female) so I would have to splice
to
use the exisiting.

Sounds to me that the most guaranteed way to buy the new product and
install
it. But I am a Ham, and more of an Appliance Operator. The formulas you
shown above were most interesting but I didn't understand the theory and
the
conclusion.

If I take it to the Marina, wow, that would be another $250.00 costs for
them to install a new tranducer, plus the costs of labor for their chap
to
install it. There is nobody at any Marina around here (Southern Ontario
Canada) that would understand what you folks have talked about above and
they would instantly and simply order the new parts and install them.
Maybe
installing less quality cables as the ones that are there are gutsy ones
and
it is a through hull fitting already in place. In fact all Marina's
around
here have very negative reputations for stuff like this.

So if you folks were in the same boat as I am, would you splice it? Would
you be worried about it working incorrectly or the possibility of it
damaging the head? I am not worried about deep water operations, never in
water over 100 feet deep and I believe these are good to 800 feet.

Would you guys simply slice it properly? Job done in an hour. Or take
Lowrance's suggestion and spend the money and time?

Thansk again for very informative and interesting discussion,

Cheers and Best Regards

73s


I certainly would not worry about the old transducer damaging the
equipment. What I would worry about is it working a bit but much less
effectively than the new transducer. Someone produced some data
suggesting the new head needs a 192kHz transducer and your old one being
200kHz (or possibly vice versa). Whether that matters depends how
sharply tuned the transducers are. I would guess that they would *not*
be very compatible but might work a bit. You could actually estimate
how sharply tuned the transducer is by using an impedance bridge with
variable frequency, but if you can't borrow one it would probably be
possible to do measurements with simpler equipment. This would not be
conclusive though. If you can find some published figures for the sound
output bandwidth of this sort of transducer it mght tell you whether to
expect useful results with about 4% mistuning. I suspect they are
actually quite sharply tuned if they are electromechanical, but I don't
even know if this is the case. The alternative being piezoelectric.

Can you temporarily rig the new transducer in a small dinghy and do A to
B comparisons alongside each other, and see whether one is much more
effective?


--
Roger Hayter