I am replacing the very old electronics on my 1977 Hunter 30 sailboat.

I want to use the Raymarine ST40 bidata instrument, but I wonder if I
can use the existing transducers for deptch and speed. The old depth
is a Standard DS1.

Any thoughts on this? If not reasonable, do I just install the new
through hull transducers and leave the old ones in? or remove the old
ones and try to fit the new ones in the same holes?

thanks,
Buddy E

"bud" wrote in
oups.com:

Any thoughts on this? If not reasonable, do I just install the new
through hull transducers and leave the old ones in? or remove the old
ones and try to fit the new ones in the same holes?



The old ones are probably not even on the same frequency as the new ones.
The old ones are probably, just guessing, 90 Khz units. New transducers in
more sophisticated systems use 200 Khz for better resolution of the bottom
and fish.

Never connect old transducers from one system to the transmitter from
another.....

Bud:

I replaced the failing KVH instruments in my 1998 boat with Raymarine ST60
speed and depth and used the old transducers. They worked fine. The old
transducers were Airmar as are the new ones that came with the Raymarines.
It was an exact wire for wire, color for color matchup.

FWIW, the thruhull glands were entirely different. So, it would not have
been possible to simply pull out the old transducer and pop in the new. If
the old transducers are incompatable with the new ones as Larry suggests in
his post, I would haul the boat, pull out the old glands and install new
ones in their place.

David
"bud" wrote in message
oups.com...
I am replacing the very old electronics on my 1977 Hunter 30 sailboat.

I want to use the Raymarine ST40 bidata instrument, but I wonder if I
can use the existing transducers for deptch and speed. The old depth
is a Standard DS1.

Any thoughts on this? If not reasonable, do I just install the new
through hull transducers and leave the old ones in? or remove the old
ones and try to fit the new ones in the same holes?

thanks,
Buddy E

I don't know anything about the DS1 stuff but I replaced my similarly
aged depth instrument (from space aged electronics!) last year and went
though the same thoughts and questions you are going though.

The problem is that transducer frequencies have changed over the years
and are now standardising at least for this year on just two frequencies
(50 and 200 KHz). It is very unlikely that your old system is either of
these or will match what a modern instrument needs. If the frequencies
of the old and new instruments are the same the transducer will probably
work. It is possible that there could be a power rating problem which
would cause you to destroy your old transducer but unless the ST40 has
some serious power output I would imagine it probably is lower power
than the old instrument and just more sensitive with better filters etc.

Most people didn't seem to think that trying the wrong transducer with
an instrument would cause damage but then again no one said it
definitely wouldn't damage it either!

In the end I just bought and fitted a new transducer which was hard work
because the new transducer was too short to go though my the fairing
block and hull so I had to make a new block and have a top hat nut made.
Any to cap it all the transducer lead was 4" too short! However, the
advantage of a new one it that you have a good chance that it will work.

Good luck.

bud wrote:
I am replacing the very old electronics on my 1977 Hunter 30 sailboat.

I want to use the Raymarine ST40 bidata instrument, but I wonder if I
can use the existing transducers for deptch and speed. The old depth
is a Standard DS1.

Any thoughts on this? If not reasonable, do I just install the new
through hull transducers and leave the old ones in? or remove the old
ones and try to fit the new ones in the same holes?

thanks,
Buddy E

In article , Steve wrote:

I don't know anything about the DS1 stuff but I replaced my similarly
aged depth instrument (from space aged electronics!) last year and went
though the same thoughts and questions you are going though.

The problem is that transducer frequencies have changed over the years
and are now standardising at least for this year on just two frequencies
(50 and 200 KHz). It is very unlikely that your old system is either of
these or will match what a modern instrument needs. If the frequencies
of the old and new instruments are the same the transducer will probably
work. It is possible that there could be a power rating problem which
would cause you to destroy your old transducer but unless the ST40 has
some serious power output I would imagine it probably is lower power
than the old instrument and just more sensitive with better filters etc.

Most people didn't seem to think that trying the wrong transducer with
an instrument would cause damage but then again no one said it
definitely wouldn't damage it either!

In the end I just bought and fitted a new transducer which was hard work
because the new transducer was too short to go though my the fairing
block and hull so I had to make a new block and have a top hat nut made.
Any to cap it all the transducer lead was 4" too short! However, the
advantage of a new one it that you have a good chance that it will work.

Good luck.

bud wrote:
I am replacing the very old electronics on my 1977 Hunter 30 sailboat.

I want to use the Raymarine ST40 bidata instrument, but I wonder if I
can use the existing transducers for deptch and speed. The old depth
is a Standard DS1.

Any thoughts on this? If not reasonable, do I just install the new
through hull transducers and leave the old ones in? or remove the old
ones and try to fit the new ones in the same holes?

thanks,
Buddy E



Actually Depthmeter Frequencies have not changed much in the last 50
years. The standard Freq's are 200Khz, 100Khz 88Khz, 50Khz, and 28Khz.

Transducer types haven't changed much either. Barium Titonate Crystals
and Magnetic Restriction type.

99% of the consumer transducers are Crystal type at either 200Khz or
50Khz, or some of the last 10 years types are dual 200/50Khz systems.

Commercial sounders that are designed for VERY DEEP waters use 28Khz
and most modern use Crystals. During WWII they used Magnetic Restriction
Transducers at 28 Khz for the old SubSig sounders.

88Khz was used for a while by the Norwegens, for their Trawl Sounders
but have mostly switch to the 200Khz/50Khz in the last 10 years.

Ross Labratories in Seattle Washington, USA had a very suscessfull
line of sounders that ran at 100Khz, and have been around for 50
years, or so. I still see them aboard vessles around the North Pacific.

Chances are that if it is a cheap consumer model, it is 200Khz and will
handle up to 50 Watts PeakPower. If it was designed for depths lower
than 100 Fathoms it will be a 50Khz and handle 100 Watts PeakPower.

Commercial Type Transducers come in many Power sizes, but mostly the
Frequencies will ususally be 50Khz, unless it is for shallow depths
(less than 300 Ft) then 200 Khz.

Bruce in alaska
--
add a 2 before @

"Bruce in Alaska" wrote in message
...
In article , Steve wrote:

I don't know anything about the DS1 stuff but I replaced my similarly
aged depth instrument (from space aged electronics!) last year and went
though the same thoughts and questions you are going though.

The problem is that transducer frequencies have changed over the years
and are now standardising at least for this year on just two frequencies
(50 and 200 KHz). It is very unlikely that your old system is either of
these or will match what a modern instrument needs. If the frequencies
of the old and new instruments are the same the transducer will probably
work. It is possible that there could be a power rating problem which
would cause you to destroy your old transducer but unless the ST40 has
some serious power output I would imagine it probably is lower power
than the old instrument and just more sensitive with better filters etc.

Most people didn't seem to think that trying the wrong transducer with
an instrument would cause damage but then again no one said it
definitely wouldn't damage it either!

In the end I just bought and fitted a new transducer which was hard work
because the new transducer was too short to go though my the fairing
block and hull so I had to make a new block and have a top hat nut made.
Any to cap it all the transducer lead was 4" too short! However, the
advantage of a new one it that you have a good chance that it will work.

Good luck.

bud wrote:
I am replacing the very old electronics on my 1977 Hunter 30 sailboat.

I want to use the Raymarine ST40 bidata instrument, but I wonder if I
can use the existing transducers for deptch and speed. The old depth
is a Standard DS1.

Any thoughts on this? If not reasonable, do I just install the new
through hull transducers and leave the old ones in? or remove the old
ones and try to fit the new ones in the same holes?

thanks,
Buddy E



Actually Depthmeter Frequencies have not changed much in the last 50
years. The standard Freq's are 200Khz, 100Khz 88Khz, 50Khz, and 28Khz.

Transducer types haven't changed much either. Barium Titonate Crystals
and Magnetic Restriction type.

99% of the consumer transducers are Crystal type at either 200Khz or
50Khz, or some of the last 10 years types are dual 200/50Khz systems.

Commercial sounders that are designed for VERY DEEP waters use 28Khz
and most modern use Crystals. During WWII they used Magnetic Restriction
Transducers at 28 Khz for the old SubSig sounders.

88Khz was used for a while by the Norwegens, for their Trawl Sounders
but have mostly switch to the 200Khz/50Khz in the last 10 years.

Ross Labratories in Seattle Washington, USA had a very suscessfull
line of sounders that ran at 100Khz, and have been around for 50
years, or so. I still see them aboard vessles around the North Pacific.

Chances are that if it is a cheap consumer model, it is 200Khz and will
handle up to 50 Watts PeakPower. If it was designed for depths lower
than 100 Fathoms it will be a 50Khz and handle 100 Watts PeakPower.

Commercial Type Transducers come in many Power sizes, but mostly the
Frequencies will ususally be 50Khz, unless it is for shallow depths
(less than 300 Ft) then 200 Khz.

Bruce in alaska
--
add a 2 before @

Other common frequencies include 120 KHz and 190 KHz.

Doug K7ABX

(Original poster here)

For what it's worth, the Standard DS1 manual specs state:
Transmitter Frequency 207kHz
Transmitter Power 40 W min. (RMS)
Transducer Requirements 1200 pF/500 ohms

And considering all I've read here and elsewhere, I may actually try to
use the old transducer if installing the new one is too much work at
this time for me.

And thanks to Bruce in Alaska for the great post.

Here's the final story on this. I decided not to try to use the old
transducers; they were very old, corroded, and the wires were brittle
and breaking.

The old depth thruhull came out easy enough. It was a 1-inch diameter
hole, and the new thruhull needs a 2-inch hole. Two drills gave their
lifes to complete this operation. The old speed transducer was a bitch
to get out - the whole assembly would turn when i tried to back off the
old nut. We had to hammer in a big knive (think crocodile dundee) into
the transducer so it could be held to allow the nut to be removed.

I used 3m 5200 fast set as bedding sealant. And I know some would be
against this, but I never plan to remove these items again!

And I like my new ST40 bidata a lot.

buddy