Hi

I replaced my Eagle Supra ID fishfinder head with a new Lowrance Elite 5
(came with new transducer). The present transducer is the round style glued
to the bottom hull (through hull).

Is there a way to test the transducer to see if it is 200khz compatible for
the new Elite 5? Can I simply splice it myself or is there a reason why I
shouldn't. I have spliced coax many times.

But I really don't want to replace that cable up to the flybridge through a
lot of fishing and pulling. I am wondering if I can use the old transducer
and cable (extension & old transducer with 10ft wire). I think the extension
is 15 feet or so.

Any ideas? I am hoping I can simply splice the plug of the old transducer
wire to the new head.

Thanks for any ideas

Cheers

73s

On 3/3/2015 5:10 PM, Tom wrote:
Hi

I replaced my Eagle Supra ID fishfinder head with a new Lowrance Elite 5
(came with new transducer). The present transducer is the round style
glued to the bottom hull (through hull).

Is there a way to test the transducer to see if it is 200khz compatible
for the new Elite 5? Can I simply splice it myself or is there a reason
why I shouldn't. I have spliced coax many times.

But I really don't want to replace that cable up to the flybridge
through a lot of fishing and pulling. I am wondering if I can use the
old transducer and cable (extension & old transducer with 10ft wire). I
think the extension is 15 feet or so.

Any ideas? I am hoping I can simply splice the plug of the old
transducer wire to the new head.

Thanks for any ideas

Cheers

73s


Coax can NEVER be spliced without causing a huge impedance mismatch at
the point of the splice. This is not 60hz or DC. But any ham with even
a minor bit of technical knowledge should understand this.

The only way you can effectively "splice" coax is with connectors, i.e.
two males and a double female. That will provide a splice with minimum
loss and impedance bump.

You would have to look at the specs for your new transducer to see if
its compatible or not. And I would recommend just replacing the coax;
you may not want to, but it's the best way.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

Jerry Stuckle wrote:
On 3/3/2015 5:10 PM, Tom wrote:
Hi

I replaced my Eagle Supra ID fishfinder head with a new Lowrance Elite 5
(came with new transducer). The present transducer is the round style
glued to the bottom hull (through hull).

Is there a way to test the transducer to see if it is 200khz compatible
for the new Elite 5? Can I simply splice it myself or is there a reason
why I shouldn't. I have spliced coax many times.

But I really don't want to replace that cable up to the flybridge
through a lot of fishing and pulling. I am wondering if I can use the
old transducer and cable (extension & old transducer with 10ft wire). I
think the extension is 15 feet or so.

Any ideas? I am hoping I can simply splice the plug of the old
transducer wire to the new head.

Thanks for any ideas

Cheers

73s


Coax can NEVER be spliced without causing a huge impedance mismatch at
the point of the splice. This is not 60hz or DC. But any ham with even
a minor bit of technical knowledge should understand this.

The only way you can effectively "splice" coax is with connectors, i.e.
two males and a double female. That will provide a splice with minimum
loss and impedance bump.

Or one male cable connector and one female cable connector.


--
Jim Pennino

On Tue, 3 Mar 2015 17:10:29 -0500, "Tom" wrote:


Is there a way to test the transducer to see if it is 200khz compatible for
the new Elite 5?

It is quite a simple procedure actually that can be discovered in one of a few
different means.

1st - Consult the product information for the required information. or
2nd - Call a local supplier/authorized service provider. Many Marinas and
boating accessory sales locations will be happy to provide you with some
examples.
3rd - Call the manufacturer.

Can I simply splice it myself or is there a reason why I
shouldn't. I have spliced coax many times.

Many people can splice coax. Very few will do it right or not at all when
inadvisable. being able to pass a signal is no indication that the splice was
done properly. Given your past posts covering a wide variety of subjects and
technologies, hardly any having to do with the actual purpose of this group, my
advice is to contact the manufacturer for advice and the proper parts for your
ideal installation.

On 3/4/2015 2:29 AM, Jeff wrote:

Coax can NEVER be spliced without causing a huge impedance mismatch at
the point of the splice. This is not 60hz or DC. But any ham with even
a minor bit of technical knowledge should understand this.


We are talking about 200kHz here not 200MHz!! Use could join the coax
with a bit of choc-block at that frequency and not see any significant
performance degradation.

Jeff


It doesn't matter if it's 200kHz. The problem remains.

And yes, there WOULD be s"significant performance degradation" if he
used a bit of choc-block.

But if you understood ANYTHING about transmission lines, you wouldn't
make such a stupid statement.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On 3/4/2015 6:11 AM, Brian Morrison wrote:
On Wed, 04 Mar 2015 05:50:02 -0500
Jerry Stuckle wrote:

On 3/4/2015 2:29 AM, Jeff wrote:

Coax can NEVER be spliced without causing a huge impedance
mismatch at the point of the splice. This is not 60hz or DC. But
any ham with even a minor bit of technical knowledge should
understand this.


We are talking about 200kHz here not 200MHz!! Use could join the
coax with a bit of choc-block at that frequency and not see any
significant performance degradation.

Jeff


It doesn't matter if it's 200kHz. The problem remains.

It depends what you mean by 'problem'.


And yes, there WOULD be s"significant performance degradation" if he
used a bit of choc-block.

That is only true if the discontinuity is a significant fraction of a
wavelength, 200kHz is about a 1.5km wavelength, in coax that would be
about 1km with typical velocity factors. A choc block is about 10mm
long, so it is 1/100,000th of a wavelength. I would not expect any major
problem but it could be used to experiment and cleaned up later if
necessary.


Incorrect. It all depends on the amount of the impedance bump. The
larger the bump (and there always will be one, even if connectors are
used), the greater the effect on the signal. And while the change in
impedance has a greater effect as you get a higher proportion of a
wavelength, a bump that's even small percentages of a wavelength can
create a significant loss.

In extreme cases, a short or open (which is much less than 1/100,000 of
a wavelength) would allow no signal through.


But if you understood ANYTHING about transmission lines, you wouldn't
make such a stupid statement.


Actually it's because Jeff understands about transmission lines that he
makes the statement, it isn't a stupid statement at all in the context
of the OP's question and the technical details of the installation.


It is a stupid statement, showing how little he understand transmission
lines.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On 3/4/2015 5:11 AM, Brian Morrison wrote:
On Wed, 04 Mar 2015 05:50:02 -0500
Jerry Stuckle wrote:

On 3/4/2015 2:29 AM, Jeff wrote:

Coax can NEVER be spliced without causing a huge impedance
mismatch at the point of the splice. This is not 60hz or DC. But
any ham with even a minor bit of technical knowledge should
understand this.


We are talking about 200kHz here not 200MHz!! Use could join the
coax with a bit of choc-block at that frequency and not see any
significant performance degradation.

Jeff


It doesn't matter if it's 200kHz. The problem remains.

It depends what you mean by 'problem'.


And yes, there WOULD be s"significant performance degradation" if he
used a bit of choc-block.

That is only true if the discontinuity is a significant fraction of a
wavelength, 200kHz is about a 1.5km wavelength, in coax that would be
about 1km with typical velocity factors. A choc block is about 10mm
long, so it is 1/100,000th of a wavelength. I would not expect any major
problem but it could be used to experiment and cleaned up later if
necessary.


But if you understood ANYTHING about transmission lines, you wouldn't
make such a stupid statement.


Actually it's because Jeff understands about transmission lines that he
makes the statement, it isn't a stupid statement at all in the context
of the OP's question and the technical details of the installation.


I agree with you and with Jeff. At 200kHz, I'm not even sure that the
coax acts as a pure transmission line anyway. I don't remember the lower
cutoff frequency. In any case, that was a good analysis, Brian. Thanks
for that.

On 3/4/2015 6:54 AM, Brian Morrison wrote:
On Wed, 04 Mar 2015 06:39:20 -0500
Jerry Stuckle wrote:

On 3/4/2015 6:11 AM, Brian Morrison wrote:
On Wed, 04 Mar 2015 05:50:02 -0500
Jerry Stuckle wrote:

On 3/4/2015 2:29 AM, Jeff wrote:

Coax can NEVER be spliced without causing a huge impedance
mismatch at the point of the splice. This is not 60hz or DC.
But any ham with even a minor bit of technical knowledge should
understand this.


We are talking about 200kHz here not 200MHz!! Use could join the
coax with a bit of choc-block at that frequency and not see any
significant performance degradation.

Jeff


It doesn't matter if it's 200kHz. The problem remains.

It depends what you mean by 'problem'.


And yes, there WOULD be s"significant performance degradation" if
he used a bit of choc-block.

That is only true if the discontinuity is a significant fraction of
a wavelength, 200kHz is about a 1.5km wavelength, in coax that
would be about 1km with typical velocity factors. A choc block is
about 10mm long, so it is 1/100,000th of a wavelength. I would not
expect any major problem but it could be used to experiment and
cleaned up later if necessary.


Incorrect. It all depends on the amount of the impedance bump. The
larger the bump (and there always will be one, even if connectors are
used), the greater the effect on the signal.

You are correct, but in my opinion you would need a very large change
in impedance over 10mm for it to make any difference at 200kHz.


And just how big is the change being proposed?

And while the change in
impedance has a greater effect as you get a higher proportion of a
wavelength, a bump that's even small percentages of a wavelength can
create a significant loss.

Shouldn't be too difficult to calculate the impedance of the choc
block, it's pretty much a balanced line.


And a coax is an unbalanced line - which complicates the calculations.


In extreme cases, a short or open (which is much less than 1/100,000
of a wavelength) would allow no signal through.

We were not discussing either a short or an open.


As I said it is an extreme - but it shows that even a small percentage
of a wavelength can have an effect, contrary to your previous statement.



But if you understood ANYTHING about transmission lines, you
wouldn't make such a stupid statement.


Actually it's because Jeff understands about transmission lines
that he makes the statement, it isn't a stupid statement at all in
the context of the OP's question and the technical details of the
installation.


It is a stupid statement, showing how little he understand
transmission lines.


I don't agree, there is plenty of latitude using imperfect connectors
at low frequencies. People have been using PL259/SO239 connectors for
frequencies as high as 500MHz for decades and yet on the VNA they most
certainly are not 50 ohm connectors above 10MHz or so. A VSWR of 2:1
creates a mismatch loss of 0.5dB, at 3:1 it's still only 1.2dB.


Connector impedance doesn't change with frequency, just as coax
impedance doesn't change with frequency. Loss will increase as
frequency increases, however.

And yes, PL259/SO239 was never meant to be an "all purpose connector"
and has greater loss than many other connectors - at any frequency.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

Hi Gents,

Thanks for all the info. Yes, I placed a post in the boating newsgroup but
they haven't the radio tech knowledge as here.

I figured that splicing the connector would affect its abilitly to perform
100%. I do not want to damage the fishfinder head. It is 500 dollars.

Transducer and cable only about 100 dollars but the time to install it is
the kicker. It will take more than a day and I worry I would be installing a
less quality one right beside what looks to be a good quality one.For no
reason.

I was hoping someone here had done a similiar upgrade and knew how to
measure that existing tranducer with about 30 feet of cable.

Thank you all for the information, but obviously the best solution would be
to replace it. I was hoping to use existing one that may work just as
equally.

Thanks again for all the info.

Cheers

73s







"Flash" wrote in message
...
On Tue, 3 Mar 2015 17:10:29 -0500, "Tom" wrote:


Is there a way to test the transducer to see if it is 200khz compatible
for
the new Elite 5?

It is quite a simple procedure actually that can be discovered in one of a
few
different means.

1st - Consult the product information for the required information. or
2nd - Call a local supplier/authorized service provider. Many Marinas and
boating accessory sales locations will be happy to provide you with some
examples.
3rd - Call the manufacturer.

Can I simply splice it myself or is there a reason why I
shouldn't. I have spliced coax many times.

Many people can splice coax. Very few will do it right or not at all when
inadvisable. being able to pass a signal is no indication that the splice
was
done properly. Given your past posts covering a wide variety of subjects
and
technologies, hardly any having to do with the actual purpose of this
group, my
advice is to contact the manufacturer for advice and the proper parts for
your
ideal installation.

On 3/4/2015 7:31 AM, Tom wrote:
Hi Gents,

Thanks for all the info. Yes, I placed a post in the boating newsgroup
but they haven't the radio tech knowledge as here.

I figured that splicing the connector would affect its abilitly to
perform 100%. I do not want to damage the fishfinder head. It is 500
dollars.

Transducer and cable only about 100 dollars but the time to install it
is the kicker. It will take more than a day and I worry I would be
installing a less quality one right beside what looks to be a good
quality one.For no reason.

I was hoping someone here had done a similiar upgrade and knew how to
measure that existing tranducer with about 30 feet of cable.

Thank you all for the information, but obviously the best solution would
be to replace it. I was hoping to use existing one that may work just as
equally.

Thanks again for all the info.

Cheers

73s







"Flash" wrote in message
...
On Tue, 3 Mar 2015 17:10:29 -0500, "Tom" wrote:


Is there a way to test the transducer to see if it is 200khz
compatible for
the new Elite 5?

It is quite a simple procedure actually that can be discovered in one
of a few
different means.

1st - Consult the product information for the required information. or
2nd - Call a local supplier/authorized service provider. Many Marinas and
boating accessory sales locations will be happy to provide you with some
examples.
3rd - Call the manufacturer.

Can I simply splice it myself or is there a reason why I
shouldn't. I have spliced coax many times.

Many people can splice coax. Very few will do it right or not at all when
inadvisable. being able to pass a signal is no indication that the
splice was
done properly. Given your past posts covering a wide variety of
subjects and
technologies, hardly any having to do with the actual purpose of this
group, my
advice is to contact the manufacturer for advice and the proper parts
for your
ideal installation.



Tom,

It may work just fine. That's why Flash made his suggestions.

You will note none of the suggestions including posting in a boating
group. I wouldn't expect them to have the knowledge - but the ones
Flash suggested should either have the info or be able to get it.

And people in this group have a lot of radio knowledge - but you're
asking about a specific item which isn't related to amateur radio.
There *might* be another fisherman here who's familiar with your
transducer, but the changes are pretty slim.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================