Type of Coax for Extending a Radar Cable
 

I'm installing a Raymarine SL72 radar and will end up about 2 meters
short on the display to radome cable. Rather than use the expensive
Raymarine extensions, I plan to build my own. I assume that the coax
should be 50 ohm, not 75, but I don't know for sure. Anyone know?
Thanks.

I am pretty sure the cable is much more than just coax. My radar
cable has coax and probably a half dozen or more other wires.
A 2 meter extention can't be all that expensive vs the potential
pitfalls of a roll-your-own solution in this situation. If it is a new
unit there may be warranty issues as well.

Doug
s/v Callista

"Mark" wrote in message
ups.com...
I'm installing a Raymarine SL72 radar and will end up about 2 meters
short on the display to radome cable. Rather than use the expensive
Raymarine extensions, I plan to build my own. I assume that the coax
should be 50 ohm, not 75, but I don't know for sure. Anyone know?
Thanks.

It is not a coax, but a multi-wire cable with proprietary connectors on the
ends. You might be able to splice in some cable extensions and recalibrate;
haven't tried it. I bought a 15m cable and sold my 10m on eBay. Good luck!
"Mark" wrote:

I'm installing a Raymarine SL72 radar and will end up about 2 meters
short on the display to radome cable. Rather than use the expensive
Raymarine extensions, I plan to build my own. I assume that the coax
should be 50 ohm, not 75, but I don't know for sure. Anyone know?
Thanks.

Mark wrote:

I'm installing a Raymarine SL72 radar and will end up about 2 meters
short on the display to radome cable. Rather than use the expensive
Raymarine extensions, I plan to build my own. I assume that the coax
should be 50 ohm, not 75, but I don't know for sure. Anyone know?
Thanks.


The coaxial conductor in the cable is for the video from the scanner to
the display. The rest of the conductors are for power and data. The
best way to so it to find a 2 meter piece of the same cable and splice
that in if you do not want to buy a longer cable.

The spices will affect the timing and there will be a small loss in
overall performance just like when you add any kind of inline
connectors. But it will work with if you have good workmanship and
material (adhesive lined heat shrink, etc.) on the splices.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

The spices will affect the timing and there will be a small loss in

I suggest Old Bay and maybe a pinch of Thyme :)

"Mark" wrote in message
ups.com...
I'm installing a Raymarine SL72 radar and will end up about 2 meters
short on the display to radome cable. Rather than use the expensive
Raymarine extensions, I plan to build my own. I assume that the coax
should be 50 ohm, not 75, but I don't know for sure. Anyone know?
Thanks.

Its a multiconductor cable with power, data and video. I have spliced a lot
of these for sailboaters after the cable was cut for stepping a mast, etc.
Also put in a connector splice for one guy who had his scanner stolen a
couple time off his trailered boat. Frankly, I would go with a 5 meter
longer cable and post the short one you have on eBay. The splices are
difficult to weatherproof, the connectors will have to purchased from a
dealer or Raymarine and you will need some good soldering skills. I use
resistance tweezers soldering tools for these connectors. Some sailboats
that cut the cable below decks have used a standard terminal strip or
Euro-connector (set screw) in a weather proof box without problems. That
method might work OK for you. The best way to avoid losses and future
intermittents is go with a new longer factory made cable.
73
Doug K7ABX

"Doug" wrote

Its a multiconductor cable with power, data and video. I have spliced a
lot
of these for sailboaters after the cable was cut for stepping a mast, etc.
Also put in a connector splice for one guy who had his scanner stolen a
couple time off his trailered boat. Frankly, I would go with a 5 meter
longer cable and post the short one you have on eBay. The splices are
difficult to weatherproof, the connectors will have to purchased from a
dealer or Raymarine and you will need some good soldering skills. I use
resistance tweezers soldering tools for these connectors. Some sailboats
that cut the cable below decks have used a standard terminal strip or
Euro-connector (set screw) in a weather proof box without problems. That
method might work OK for you. The best way to avoid losses and future
intermittents is go with a new longer factory made cable.

Doug,
I have a Furuno radar - old model 1720.

When I bought the boat, the cable had already been cut and an attempt had
been made to put in a terminal strip using crimp on spade connectors. I had
this working, but the signal conductor inside the small co-ax was so
fragile, it kept breaking off.
I also had some Euro-style terminal blocks, but I don't think they would
have been better.

I decide to try an Amphenol circular plastic multi connector plug and
receptacle - Quite a soldering and assembly job - there are a lot of
conductors! This seems to work, but once in a while I still get faults. The
assemble has proper sealing boots and I wrap it with self-amalg tape, so no
moisture gets in. Maybe I should use some dielectric grease?

I am thinking of relocating the radar to a stern post mount. If I did this,
I would have no joint, but I would have to somehow re-attach one of the
radar connectors - either the radome end or the display end depending on
which piece of cable I used. Can I re-use these? Any suggestions or advice
on this?

If you do it, leave the radar end attached. It's out in the weather. Presumably
the display end is at least more sheltered. And ask Furuno if replacement cables
are available.



"Windjammer" wrote in message ...

"Doug" wrote

Its a multiconductor cable with power, data and video. I have spliced a
lot
of these for sailboaters after the cable was cut for stepping a mast, etc.
Also put in a connector splice for one guy who had his scanner stolen a
couple time off his trailered boat. Frankly, I would go with a 5 meter
longer cable and post the short one you have on eBay. The splices are
difficult to weatherproof, the connectors will have to purchased from a
dealer or Raymarine and you will need some good soldering skills. I use
resistance tweezers soldering tools for these connectors. Some sailboats
that cut the cable below decks have used a standard terminal strip or
Euro-connector (set screw) in a weather proof box without problems. That
method might work OK for you. The best way to avoid losses and future
intermittents is go with a new longer factory made cable.

Doug,
I have a Furuno radar - old model 1720.

When I bought the boat, the cable had already been cut and an attempt had
been made to put in a terminal strip using crimp on spade connectors. I had
this working, but the signal conductor inside the small co-ax was so
fragile, it kept breaking off.
I also had some Euro-style terminal blocks, but I don't think they would
have been better.

I decide to try an Amphenol circular plastic multi connector plug and
receptacle - Quite a soldering and assembly job - there are a lot of
conductors! This seems to work, but once in a while I still get faults. The
assemble has proper sealing boots and I wrap it with self-amalg tape, so no
moisture gets in. Maybe I should use some dielectric grease?

I am thinking of relocating the radar to a stern post mount. If I did this,
I would have no joint, but I would have to somehow re-attach one of the
radar connectors - either the radome end or the display end depending on
which piece of cable I used. Can I re-use these? Any suggestions or advice
on this?

In article ,
"Windjammer" wrote:

"Doug" wrote

Its a multiconductor cable with power, data and video. I have spliced a
lot
of these for sailboaters after the cable was cut for stepping a mast, etc.
Also put in a connector splice for one guy who had his scanner stolen a
couple time off his trailered boat. Frankly, I would go with a 5 meter
longer cable and post the short one you have on eBay. The splices are
difficult to weatherproof, the connectors will have to purchased from a
dealer or Raymarine and you will need some good soldering skills. I use
resistance tweezers soldering tools for these connectors. Some sailboats
that cut the cable below decks have used a standard terminal strip or
Euro-connector (set screw) in a weather proof box without problems. That
method might work OK for you. The best way to avoid losses and future
intermittents is go with a new longer factory made cable.

Doug,
I have a Furuno radar - old model 1720.

When I bought the boat, the cable had already been cut and an attempt had
been made to put in a terminal strip using crimp on spade connectors. I had
this working, but the signal conductor inside the small co-ax was so
fragile, it kept breaking off.
I also had some Euro-style terminal blocks, but I don't think they would
have been better.

I decide to try an Amphenol circular plastic multi connector plug and
receptacle - Quite a soldering and assembly job - there are a lot of
conductors! This seems to work, but once in a while I still get faults. The
assemble has proper sealing boots and I wrap it with self-amalg tape, so no
moisture gets in. Maybe I should use some dielectric grease?

I am thinking of relocating the radar to a stern post mount. If I did this,
I would have no joint, but I would have to somehow re-attach one of the
radar connectors - either the radome end or the display end depending on
which piece of cable I used. Can I re-use these? Any suggestions or advice
on this?




You have come across one of the minor flaws in the Furuno Radars.
That little center conductor has caused a lot of us Marine ET's
to feed our families, over the years. My solution was to strip
the insulation back 3/8" and then fold the wires back over the
isulatio., Then insert the insulation and wire into a larger
crimp lug, and carefully crimp both the wire and insulation in
the bigger lug. Then run just a touck of solder into the crimped
connection. Never had one come back with a broken video line
after that.


Bruce in alaska
--
add a 2 before @

Can you use a automatic solenoid changover switch when switching over from
shore power to an Onan MDJA diesel genset? The instructions I have
indicate that the load must be removed first, the genset started and then
the load applied. Is there a way to do that with a solenoid operated
automatic transfer switch?

MickinDallas

MickinDallas wrote:

Can you use a automatic solenoid changover switch when switching over from
shore power to an Onan MDJA diesel genset? The instructions I have
indicate that the load must be removed first, the genset started and then
the load applied. Is there a way to do that with a solenoid operated
automatic transfer switch?

MickinDallas


If you are on shore power, start the genset, then use a switch or
solenoid (relay) to switch over. An automatic control circuit is not
a purely simple arrangement.

"Solenoid" usually refers to a relay type coil operating a single
pole single throw switch or a mechanical actuator for something
else, as opposed to a relay switching arrangement, which would
actuate a fancier switch, or set of switches. (That's a local
technical use, about which otherwise mindless 'droid electrical
engineering students would centre a beer drinking preamble to
pointless fisticuffs.)

A relay contains a coil, which is often considered a solenoid if it
operates from D.C. Stroking differently produces different folks,
and loose language sinks ships as well as swelling lips.

Shutting off the genset could cause the switchover relay to drop
back to the shore input feed so long as the power from the shore
could not conflict with the power for the relay. It would be easy to
make a mistake in the wiring which would cause such a mishap. The
two Alternating current power sources must never be connected
together, even for an instant, as the explosion would cause
complaints about blackouts, spilled drinks, clouds of smoke in the
clubhouse, etc. A manual switch could force the feed to go back to
shore power while the genset is running by controlling the operation
of the relay / solenoid. This arrangement should be OK and is
relatively simple and safe.

The genset should start up OK with only the small load of a relay
present. You may need a small delay circuit to get the genny up to
full speed before switching over. You may prefer to do this
switchover manually, as it would be much simpler. If you are doing
it manually, a simple, large DPDT switch in a box near the genny
start control should suffice, so long as you do not need
uninterruptible power for some loads such as computers. In that
case, a commercial UPS using chargers, batteries, and inverters
should handle that load while switchover occurrs. A laptop computer
already contains circuitry to enable lossless operation while
unplugging it's AC power, and plugging it back in, which is about
the same as switching the AC power distribution from one source to
the other.

Commercial automatic switchovers are available. Typical household
devices, sheltered from the weather and sea spray should be fine.

If you insist on home brewing some nonstandard automatic operation,
you need to decide and describe precisely how you want the
arrangenent to work, and how automatic you want it. You may want the
genny to start automatically whenever shore power is not present,
etc, to preserve refrigeration and power bilge pumps. There is no
end to the ingenuity of the uneducated in dreaming up unlikely,
false or fanciful requirements.

Since you had to ask, perhaps you should start with a basic
electricity course, or consult with a professional.

You have to pay properly qualified professionals, but at least, if
they make a mistake and sink you or kill you, your insurance is not
jepoardised.

Terry K

In article
outelectronicequipment
..com,
"MickinDallas" wrote:

Can you use a automatic solenoid changover switch when switching over from
shore power to an Onan MDJA diesel genset? The instructions I have
indicate that the load must be removed first, the genset started and then
the load applied. Is there a way to do that with a solenoid operated
automatic transfer switch?

MickinDallas


The bigger question is how long do you let the MDJA warm up before you
apply the load to it, and does this all happen automatically? There are
a pile of Third Party sequencers that can do the job, but I have never
seen an ONAN Labled Setup for a MDJA Genset. Most users prefer to do
the whole job manually, so they can monitor and adjust the sequence, as
required for good operating practices.

Bruce in alaska
--
add a 2 before @