I am about to start a major rewire on the boat. Which brings up some
ideas and questions.

Idea/question 1. I have seen those expensive power filters for boating
electronics. Why can't I just build a dedicated power buss and drop
some capacitors across the power feeds to each instrument? As in going
back to when we had to build our own power supplies for computer floppy
drives.

The electronics I will be trying to protect are ...
VHF
GPS/Chartplotter combo
Scanning sonar (Interphase)
Radar
SSB
Autopilot

And I may put a second radar and/or scanning sonar at the upper helm.

Question 2. When and where should I use twisted pairs and why not just
twist everything, everywhere?

Earl Haase

Not familiar with the problem you are referring to. What expensive filters
are you refering to? I've never come across what you seem to be asking
about.

Doug
s/v Callista

"Earl Haase" wrote in message
...
I am about to start a major rewire on the boat. Which brings up some
ideas and questions.

Idea/question 1. I have seen those expensive power filters for boating
electronics. Why can't I just build a dedicated power buss and drop
some capacitors across the power feeds to each instrument? As in going
back to when we had to build our own power supplies for computer floppy
drives.

The electronics I will be trying to protect are ...
VHF
GPS/Chartplotter combo
Scanning sonar (Interphase)
Radar
SSB
Autopilot

And I may put a second radar and/or scanning sonar at the upper helm.

Question 2. When and where should I use twisted pairs and why not just
twist everything, everywhere?

Earl Haase

In article ,
Earl Haase wrote:

The electronics I will be trying to protect are ...
VHF
GPS/Chartplotter combo
Scanning sonar (Interphase)
Radar
SSB
Autopilot

And I may put a second radar and/or scanning sonar at the upper helm.

Question 2. When and where should I use twisted pairs and why not just
twist everything, everywhere?

Earl Haase


What are you protecting the above equipment from? Power spikes?
RFI? Bird ****? Just what?

Bruce in alaska
--
add a 2 before @

Doug,
Given your previous posts on this group I'm a little surprised you
haven't heard of or seen these before. The power filters I'm talking
about are also called noise filters. They connect to the power lines
going to the boat electronics to filter out problems caused by other
equipment. This could be other electronics like maybe using the chart
plotter interferes with use of the VHF. Or you might get noise from the
engine ignition system or alternator. Maybe running your windshield
wipers wipes out your VHF so you can't talk and look through the
windshield at the same time. There are also filters for this equipment
too in order to keep the noise coming out of these from getting into the
system in the first place. You can check online at the Newmar company
site for examples. They run from around $70 per instrument up to
hundreds or even a thousand each dollars depending on what system you
choose.

Bruce,
In the past you have posted here about all your experience in
electronics repair. I am confident that you knew what I was asking.
After all, I just asked a couple of questions in order to get the
opinion of others who would hopefully share their collective knowledge.
I don't know why this ****ed you off so much but if you don't want to
play nice please feel free not to play at all.

Earl

Bruce,

Have you actually had problems as extreme as you are relating to
here or have you just been reading the catalogs and seeing
products that you feel will keep ypu out of trouble?

Noise filters I have heard of. Never heard them referred to as
power filters though. I've never had to resort to anything other than a
few ferrite beads to solve noise problems. Some minor comments
below.

Doug
s/v Callista

"Earl Haase" wrote in message
...
Doug,
Given your previous posts on this group I'm a little surprised you
haven't heard of or seen these before. The power filters I'm talking
about are also called noise filters. They connect to the power lines
going to the boat electronics to filter out problems caused by other
equipment.

OK.

This could be other electronics like maybe using the chart
plotter interferes with use of the VHF.

Have both and no interference between them. Most electronics are
equipped to prevent noise from being introduced back into the power
supply lines.

Or you might get noise from the
engine ignition system or alternator.

I have a diesel engine, but never had any problem with alternator noise.

Maybe running your windshield
wipers wipes out your VHF so you can't talk and look through the
windshield at the same time.

Doubtful that it keeps you from talking. Might keep you from receiving
though. Anyway, what is a windshield wiper?

There are also filters for this equipment
too in order to keep the noise coming out of these from getting into the
system in the first place. You can check online at the Newmar company
site for examples. They run from around $70 per instrument up to
hundreds or even a thousand each dollars depending on what system you
choose.

Wow! Seems like snake oil to me. I have a pretty full complement of
electronics on board and have had no problems at all until I installed
email via ham using a laptop. The high power HF emissions did cause
some problems with the computer. A few ferrite beads and an isolator
solved those problems.

Bruce,
In the past you have posted here about all your experience in
electronics repair. I am confident that you knew what I was asking.
After all, I just asked a couple of questions in order to get the
opinion of others who would hopefully share their collective knowledge.
I don't know why this ****ed you off so much but if you don't want to
play nice please feel free not to play at all.

Earl

Doug,

Thanks for the response. All the instruments I am installing are new.
They are going on a 1970 Chris Craft that is nearing completion of a
four year restoration. I am looking at filtering to avoid problems
before they start. The boat is in Tampa and when I get it in the water
I will be leaving to take the boat back home to the Caribbean. I will
not have time to play with things very much before leaving so I want to
fix it before it breaks. The only shake down will be as I cross the
state to the east coast through the river & canal.

Tell me more about these ferrite beads. An Autohelm autopilot I have
(will not be part of this installation) included installation
instructions to use them. The instructions did not go into detail on
why they insisted I needed them.

Thanks again,

Earl

Earl,

I've never come across noise problems to the extent that you
are expecting. I wouldn't go spending alot of money on filtering
until you find a problem bad enough to warrant it. Specifically,
I've never had any problems with instruments and VHF. I do get
some noise from the inverter into the SSB. The inverter is running
the computer but I can just turn it off and let it run on its internal
battery. The noise is only a problem when picking out weak stations.

A ferrite bead is just a collar of ferrite that clamps around a wire. They
filter out any noise that may be induced in the wire. I have them
in some of the wires leading to the autopilot modules. The power leads
to the SSB and the computer. They only cost a few bucks each.

Doug
s/v CAllista

"Earl Haase" wrote in message
...
Doug,

Thanks for the response. All the instruments I am installing are new.
They are going on a 1970 Chris Craft that is nearing completion of a
four year restoration. I am looking at filtering to avoid problems
before they start. The boat is in Tampa and when I get it in the water
I will be leaving to take the boat back home to the Caribbean. I will
not have time to play with things very much before leaving so I want to
fix it before it breaks. The only shake down will be as I cross the
state to the east coast through the river & canal.

Tell me more about these ferrite beads. An Autohelm autopilot I have
(will not be part of this installation) included installation
instructions to use them. The instructions did not go into detail on
why they insisted I needed them.

Thanks again,

Earl

In article ,
"Doug Dotson" wrote:

Bruce,

Have you actually had problems as extreme as you are relating to
here or have you just been reading the catalogs and seeing
products that you feel will keep ypu out of trouble?

Noise filters I have heard of. Never heard them referred to as
power filters though. I've never had to resort to anything other than a
few ferrite beads to solve noise problems. Some minor comments
below.

Doug
s/v Callista

Oh yea, I have seen some real Doozies of RFI in the last 35 years that
defied the easy fixes that most folks use. Noise is ALWAYS easier to
stop at the source, than at the receiver. Inverters aren't to bad if
you get them installed with short battery leads, and they are designed
for the Marine Enviormewnt. Trace used to build some fairly quiet ones.
Radars have a very nasty habit of haviung the interconnect cable come
ungrounded one one end or the other and radiating noise at the PRR.
the Decca 101's were notorious for this. some of the Rartheon Marine
Radars run Chopped Dc up the interdeck cable, to power the transmitter
and if the cable ground opens, they radiate like crazy. Most of the
alaskan fishing fleet has Oil fired stoves in the galley that use DC
Blower Motors. These make a big racket when not suppressed with Caps.
Refer motors are the same game as well. If you really want a quiet
MF/HF boat, you got to pay the price in RFI Suppression.


Bruce in alaska

--
Bruce (semiretired powderman & exFCC Field Inspector for Southeastern Alaska)
add a 2 before @
Bruce Gordon * Debora Gordon R.N. Bruce's Trading Post
P.O. Box EXI Excursion Inlet South
Juneau, Alaska 99850 Excursion Inlet, Alaska 99850
www.btpost.net www.99850.net

I was referring to the project at hand. I know that there are tons
of potential noise problems but what about actual problems with
the installation under consideration? I can;t see sinking alot of time
anf money based upon worst-case scenarios.

Doug
s/v Callista

"Bruce Gordon" wrote in message
...
In article ,
"Doug Dotson" wrote:

Bruce,

Have you actually had problems as extreme as you are relating to
here or have you just been reading the catalogs and seeing
products that you feel will keep ypu out of trouble?

Noise filters I have heard of. Never heard them referred to as
power filters though. I've never had to resort to anything other than a
few ferrite beads to solve noise problems. Some minor comments
below.

Doug
s/v Callista

Oh yea, I have seen some real Doozies of RFI in the last 35 years that
defied the easy fixes that most folks use. Noise is ALWAYS easier to
stop at the source, than at the receiver. Inverters aren't to bad if
you get them installed with short battery leads, and they are designed
for the Marine Enviormewnt. Trace used to build some fairly quiet ones.
Radars have a very nasty habit of haviung the interconnect cable come
ungrounded one one end or the other and radiating noise at the PRR.
the Decca 101's were notorious for this. some of the Rartheon Marine
Radars run Chopped Dc up the interdeck cable, to power the transmitter
and if the cable ground opens, they radiate like crazy. Most of the
alaskan fishing fleet has Oil fired stoves in the galley that use DC
Blower Motors. These make a big racket when not suppressed with Caps.
Refer motors are the same game as well. If you really want a quiet
MF/HF boat, you got to pay the price in RFI Suppression.


Bruce in alaska

--
Bruce (semiretired powderman & exFCC Field Inspector for Southeastern
Alaska)
add a 2 before @
Bruce Gordon * Debora Gordon R.N. Bruce's Trading Post
P.O. Box EXI Excursion Inlet South
Juneau, Alaska 99850 Excursion Inlet, Alaska 99850
www.btpost.net www.99850.net

In article ,
"Doug Dotson" wrote:

I was referring to the project at hand.

It was not my project. I was replying to a previous Poster.


Bruce in alaska
--
add a 2 before @