David Rinnan kirjoitti:
Hi all,

I have a problem with my simrad 2kw radome. I tend to get a message
along the lines of "heading lost connection" or similar. I have to press
"CLR" to get back to receiving mode.

The problem only occur when the sea is rough and this is why I am
considering the mount being the faulty parameter. I had a quick email
correspondance with Simrad but they did not seem to be on top of things
and suggested I send in the units for software upgrade. Could this be
the problem?

Considering how important the radar is I have been very close to just
throwing the simrad over board and bying something else (i got the
simrad stuff with my boat).

I would however be very sad if I buy a new radar just to discover that
the mounting is the problem.

I should add that the boat is a Nordstar Patrol 28. You can see an image
from the manufacturer via this link.
http://www.nordstar.fi/img/ns28patrol/1.jpg

My radar is mounted on the port side of the pole next to the port
lantern. The pole is heavy duty BUT it can be tilted for the boat to
pass under bridges or during winter storage. This is why you can see the
ropes (pardon my french here but im from sweden and my boat-english is
crap) from the roof to the pole. The ropes can be tightened pretty hard
but it is impossible to tighten so much that the pole dont move. The
"ropes" on the sides are similar to what you see on a sail boat with
very good tightening screws and its metal wires with plastic on the
outside. The forward rope is actually just a rope.. but the rope goes
trough a wheel making it possible to tighten pretty hard. I am
considering changing the rope to a wire with a similar tightening
mechanism as on the sides (might have to add a sturdier mount on the
roof for that to work though).

Saying that the pole moves is bit of an exageration.. but I guess it
"moves" more than if it couldnt be tilted.

I dont know what I am getting at here.. but my thinking is that given
the bouncing and jumping arround with a boat in heavy sea - shouldnt the
radar be able to cope with that without loosing its bearing or
connection? The pole might not be as sturdy as if it was fixed but that
litle extra movement should be able to create this much problem, or?

3rd option. can it be that the GPS signal is somewhat lossy and this is
the cause for the problem. the error message does state that it looses
bearing. I dont have a separate electronic compass installed yet so the
radar is relying on the GPS for bearing.

Ok friends, 3 options available - which one do you think is the cause
for my problems?

I have Simrad CR34 as the main unit and a slave station DS44 indoors. A
separate power box for the radar, a 2kw radome.

I just found a place where I could upload my own pic where you can see
my mounting of the radome.
http://img57.imageshack.us/img57/694...657copyyp0.jpg

Thanks and safe boating to you all

regards
david

PS note the outside "flybridge" driving possition that is possible on
this boat. That is why the radome is not mounted on the roof. Ds

------------------------------------------------------------------------

Lost Bearing, bearing pulse error etc. sounds to me like loose
connection with the cable connecting transmitter and display unit. I
would check the cable connections inside the radome at first.

Secondly it could also refer to power outage at the transmitter, I have
encountered this problem with both Raymarine and Simrad radars. Mostly
it occurs in sailing boats when battery level is getting lower but is
still enough to power the display. Only thing you get is the lost
bearing pulse which means that antenna is not rotating.

But back in to your case, with rough seas loose cables inside connectors
can cause this problem. Try to pull each wire separately to see wheter
they come out, but better if there is warranty you can let others do it.

/Jani

Hi Jani,

That could be the solution!

I was out this weekend and it was pretty rough weather. Hard wind, light
fog and hard rain. At one stage the fog was getting worse and so did the
waves. That was when the error message came. I pressed CLR and expected
everything to work again (usally 30 seconds to 2 minutes) but was
surpised to see that the GPS coordinates where blinking.

At that stage being without GPS was worse than radar. I turned off the
radar and 1-2 minutes later I had GPS connection again.

I guess I have to disasemble everything and check cables etc.

Thanks for the tip


I just as well might take some time to describe the problem a litle bit
more. When the problem occur I can see the radar starting to spread out
over the screen as it moves. Its like the radar info is frozen but the
spinning indicator continues to move. When it has gone one rotation on
the screen I see the exact same info everywhere on the radar screen,
repeated around the full circle. A second or two later the error message
pops up and I have to press CLR. Very shortly after pressing CLR
everything is working, including the radar. Often just a couple of
seconds after pressing CLR.

I guess this indicates that the radar is not moving OR that the radar is
moving but the GPS is not feeding cords and thus the radar hickups and
fail..


What do people think about how sturdy a radar mount needs to be? Is my
assumption correct that it could cause a problem with instability or is
it a fact that radomes are constructed to work under rough conditions
and therefore do not really care if the mount is a little "loose".

Might it be the case that the bouncing of the boat prevents the radar
from turning properly? In that case I can use the radome as a table or a
frisbie or something else not realted to marine activities during rough
sea.

Cheers
david


flying sailor wrote:
David Rinnan kirjoitti:

Hi all,

I have a problem with my simrad 2kw radome. I tend to get a message
along the lines of "heading lost connection" or similar. I have to
press "CLR" to get back to receiving mode.

The problem only occur when the sea is rough and this is why I am
considering the mount being the faulty parameter. I had a quick email
correspondance with Simrad but they did not seem to be on top of
things and suggested I send in the units for software upgrade. Could
this be the problem?

Considering how important the radar is I have been very close to just
throwing the simrad over board and bying something else (i got the
simrad stuff with my boat).

I would however be very sad if I buy a new radar just to discover that
the mounting is the problem.

I should add that the boat is a Nordstar Patrol 28. You can see an
image from the manufacturer via this link.
http://www.nordstar.fi/img/ns28patrol/1.jpg

My radar is mounted on the port side of the pole next to the port
lantern. The pole is heavy duty BUT it can be tilted for the boat to
pass under bridges or during winter storage. This is why you can see
the ropes (pardon my french here but im from sweden and my
boat-english is crap) from the roof to the pole. The ropes can be
tightened pretty hard but it is impossible to tighten so much that the
pole dont move. The "ropes" on the sides are similar to what you see
on a sail boat with very good tightening screws and its metal wires
with plastic on the outside. The forward rope is actually just a
rope.. but the rope goes trough a wheel making it possible to tighten
pretty hard. I am considering changing the rope to a wire with a
similar tightening mechanism as on the sides (might have to add a
sturdier mount on the roof for that to work though).

Saying that the pole moves is bit of an exageration.. but I guess it
"moves" more than if it couldnt be tilted.

I dont know what I am getting at here.. but my thinking is that given
the bouncing and jumping arround with a boat in heavy sea - shouldnt
the radar be able to cope with that without loosing its bearing or
connection? The pole might not be as sturdy as if it was fixed but
that litle extra movement should be able to create this much problem, or?

3rd option. can it be that the GPS signal is somewhat lossy and this
is the cause for the problem. the error message does state that it
looses bearing. I dont have a separate electronic compass installed
yet so the radar is relying on the GPS for bearing.

Ok friends, 3 options available - which one do you think is the cause
for my problems?

I have Simrad CR34 as the main unit and a slave station DS44 indoors.
A separate power box for the radar, a 2kw radome.

I just found a place where I could upload my own pic where you can see
my mounting of the radome.
http://img57.imageshack.us/img57/694...657copyyp0.jpg

Thanks and safe boating to you all

regards
david

PS note the outside "flybridge" driving possition that is possible on
this boat. That is why the radome is not mounted on the roof. Ds

------------------------------------------------------------------------

Lost Bearing, bearing pulse error etc. sounds to me like loose
connection with the cable connecting transmitter and display unit. I
would check the cable connections inside the radome at first.

Secondly it could also refer to power outage at the transmitter, I have
encountered this problem with both Raymarine and Simrad radars. Mostly
it occurs in sailing boats when battery level is getting lower but is
still enough to power the display. Only thing you get is the lost
bearing pulse which means that antenna is not rotating.

But back in to your case, with rough seas loose cables inside connectors
can cause this problem. Try to pull each wire separately to see wheter
they come out, but better if there is warranty you can let others do it.

/Jani

David Rinnan kirjoitti:
Hi Jani,

That could be the solution!

I was out this weekend and it was pretty rough weather. Hard wind, light
fog and hard rain. At one stage the fog was getting worse and so did the
waves. That was when the error message came. I pressed CLR and expected
everything to work again (usally 30 seconds to 2 minutes) but was
surpised to see that the GPS coordinates where blinking.

At that stage being without GPS was worse than radar. I turned off the
radar and 1-2 minutes later I had GPS connection again.

I guess I have to disasemble everything and check cables etc.

Thanks for the tip


I just as well might take some time to describe the problem a litle bit
more. When the problem occur I can see the radar starting to spread out
over the screen as it moves. Its like the radar info is frozen but the
spinning indicator continues to move. When it has gone one rotation on
the screen I see the exact same info everywhere on the radar screen,
repeated around the full circle. A second or two later the error message
pops up and I have to press CLR. Very shortly after pressing CLR
everything is working, including the radar. Often just a couple of
seconds after pressing CLR.

I guess this indicates that the radar is not moving OR that the radar is
moving but the GPS is not feeding cords and thus the radar hickups and
fail..
// gps should not be related with radar picture



What do people think about how sturdy a radar mount needs to be? Is my
assumption correct that it could cause a problem with instability or is
it a fact that radomes are constructed to work under rough conditions
and therefore do not really care if the mount is a little "loose".

//motor boat has lots of vibrations and other movements especially
workboats, these radars are designed to be used in such conditions. But
of course if there is a manufacturing fault, vibrations or shocks could
show up some bad behaviour

Might it be the case that the bouncing of the boat prevents the radar
from turning properly? In that case I can use the radome as a table or a
frisbie or something else not realted to marine activities during rough
sea.

//no, not even if you had an open array antenna. Again same antennas are
used with small RIBs over 50kts and high seas.


Check the cabling inside the radome first then check the connector
behind your display or vice versa.

If this does not help, I believe it is worth of calling service engineer
to check the situation. If you happen to be in Finland, then I can
recommend some...
Jani
Cheers
david


flying sailor wrote:
David Rinnan kirjoitti:

Hi all,

I have a problem with my simrad 2kw radome. I tend to get a message
along the lines of "heading lost connection" or similar. I have to
press "CLR" to get back to receiving mode.

The problem only occur when the sea is rough and this is why I am
considering the mount being the faulty parameter. I had a quick email
correspondance with Simrad but they did not seem to be on top of
things and suggested I send in the units for software upgrade. Could
this be the problem?

Considering how important the radar is I have been very close to just
throwing the simrad over board and bying something else (i got the
simrad stuff with my boat).

I would however be very sad if I buy a new radar just to discover
that the mounting is the problem.

I should add that the boat is a Nordstar Patrol 28. You can see an
image from the manufacturer via this link.
http://www.nordstar.fi/img/ns28patrol/1.jpg

My radar is mounted on the port side of the pole next to the port
lantern. The pole is heavy duty BUT it can be tilted for the boat to
pass under bridges or during winter storage. This is why you can see
the ropes (pardon my french here but im from sweden and my
boat-english is crap) from the roof to the pole. The ropes can be
tightened pretty hard but it is impossible to tighten so much that
the pole dont move. The "ropes" on the sides are similar to what you
see on a sail boat with very good tightening screws and its metal
wires with plastic on the outside. The forward rope is actually just
a rope.. but the rope goes trough a wheel making it possible to
tighten pretty hard. I am considering changing the rope to a wire
with a similar tightening mechanism as on the sides (might have to
add a sturdier mount on the roof for that to work though).

Saying that the pole moves is bit of an exageration.. but I guess it
"moves" more than if it couldnt be tilted.

I dont know what I am getting at here.. but my thinking is that given
the bouncing and jumping arround with a boat in heavy sea - shouldnt
the radar be able to cope with that without loosing its bearing or
connection? The pole might not be as sturdy as if it was fixed but
that litle extra movement should be able to create this much problem,
or?

3rd option. can it be that the GPS signal is somewhat lossy and this
is the cause for the problem. the error message does state that it
looses bearing. I dont have a separate electronic compass installed
yet so the radar is relying on the GPS for bearing.

Ok friends, 3 options available - which one do you think is the cause
for my problems?

I have Simrad CR34 as the main unit and a slave station DS44 indoors.
A separate power box for the radar, a 2kw radome.

I just found a place where I could upload my own pic where you can
see my mounting of the radome.
http://img57.imageshack.us/img57/694...657copyyp0.jpg

Thanks and safe boating to you all

regards
david

PS note the outside "flybridge" driving possition that is possible on
this boat. That is why the radome is not mounted on the roof. Ds

------------------------------------------------------------------------

Lost Bearing, bearing pulse error etc. sounds to me like loose
connection with the cable connecting transmitter and display unit. I
would check the cable connections inside the radome at first.

Secondly it could also refer to power outage at the transmitter, I
have encountered this problem with both Raymarine and Simrad radars.
Mostly it occurs in sailing boats when battery level is getting lower
but is still enough to power the display. Only thing you get is the
lost bearing pulse which means that antenna is not rotating.

But back in to your case, with rough seas loose cables inside
connectors can cause this problem. Try to pull each wire separately to
see wheter they come out, but better if there is warranty you can let
others do it.

/Jani

In article ,
David Rinnan wrote:

Hi Jani,


Lost Bearing, bearing pulse error etc. sounds to me like loose
connection with the cable connecting transmitter and display unit. I
would check the cable connections inside the radome at first.

Secondly it could also refer to power outage at the transmitter, I have
encountered this problem with both Raymarine and Simrad radars. Mostly
it occurs in sailing boats when battery level is getting lower but is
still enough to power the display. Only thing you get is the lost
bearing pulse which means that antenna is not rotating.

But back in to your case, with rough seas loose cables inside connectors
can cause this problem. Try to pull each wire separately to see wheter
they come out, but better if there is warranty you can let others do it.

/Jani

One thing to look at very closely, is the way the bearing information
is being generated in the Antenna Unit. In the 2nd and 3rd generation
Furuno Units, the antenna bearing information was generated by a
"Chopper Wheel" with an LED OptoPickup looking thru the Chopper Wheel
holes. This generated pulses, are equated to an angular rotation
of the the antenna.

If the seal leaked on these type units and some of the the Chopper Wheel
Holes filled with moisture, they wouldn't allow the LED InferRed Light
thru to the Pickup and pulses would be missed, and cause the Mechanical
Servo Motor that turned the Yoke coil to slow down and the picture would
rotate backwards.

On 4th and 5th Generation Radars, with Digital Displays, if the Pulse
Stream coming from the Antenna Unit is loosing pulses, the CPU that
Generates the display can't figure out how to display the receive data,
and has an Error Routine that does just what the OP discribes in his
second post. Hitting the "Clear Button" causes the CPU to wait for the
next "Heading Flash" and then start the routine that displays the
Radar Data, from Heading Flash, clockwise at the angular Pulse Rate of
the Bearing Pulses. Should some of those pulses come up missing, and the
next Heading Flash, not come with the right timing, then the CPU will
jump to the Display Error Routine again, and you start all over again.

Sometimes "Older" is better, and the old analog display would at least
give you a picture even if the display went backwards a few degrees per
revolution. Digital Displays can't do that, because of the way the
CPU has to display the data.

Look at the way the Bearing Data is generated, and look for missing
pulses in that system.

Bruce in alaska I know Old Chief Lynn has seen the above senerio....
--
add a 2 before @

Hi Bruce,

Thanks for all the information!

Just to make sure I understand this.. When you say "look at the way the
bearing data is generated" are you then refering to the GPS, in my case,
since I havnt installed a separate compass yet?

Regards
david


Bruce in Alaska wrote:
Look at the way the Bearing Data is generated, and look for missing
pulses in that system.

Bruce in alaska I know Old Chief Lynn has seen the above senerio....

Hi Jani,

Thanks again for your reply.

I seem to have a couple of options to look into more deply now. My main
worry was isntability but that option seems the least likly. That is
very comforting.

I have taken the boat home to sweden from finland already. So ill have
to find tech ppl over here if I cant solve it my self :/

Cheers
david


flying sailor wrote:
//no, not even if you had an open array antenna. Again same antennas are
used with small RIBs over 50kts and high seas.


Check the cabling inside the radome first then check the connector
behind your display or vice versa.

If this does not help, I believe it is worth of calling service engineer
to check the situation. If you happen to be in Finland, then I can
recommend some...
Jani

David Rinnan wrote:
Hi Bruce,

Thanks for all the information!

Just to make sure I understand this.. When you say "look at the way the
bearing data is generated" are you then refering to the GPS, in my case,
since I havnt installed a separate compass yet?


It is not about the GPS, he is talking about bearing as in the direction
the radar's rotating radiator or antenna is pointed (relative to the
center line of the boat). That bearing is the direction the radar pulse
was sent to and received from. If that bearing display is off, the
relative bearing to a radar contact from the boat would incorrect.

Does your boat have a flux gate compass? A boat with a radar system
and/or a autopilot really should have a flux gate compass for
determining the boats bearing when not moving. A flux gate compass
knows the bearing at all times (boat moving or not) and sends it to
other devices as a NMEA sentence.

If you do not have a flux gate compass your radar has probably been set
up to use the heading data from the NMEA sentences from the GPS. GPS
headings are only reliable when you are moving, they float around when
you are stopped and do not stay relative to the bow of the boat.

In the above I use heading and bearing as follows:

heading - the direction the boat is moving
bearing - the direction the bow of the boat is pointing

Some people will want to argue about the terms and their use but I'm not
likely to indulge in discussion about it. :) There are many different
definitions and schools of thought on some navigation terms and none of
them are wrong.

Jack

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

"Bruce in Alaska" wrote in message
...
In article ,
David Rinnan wrote:

Hi Jani,


Lost Bearing, bearing pulse error etc. sounds to me like loose
connection with the cable connecting transmitter and display unit. I
would check the cable connections inside the radome at first.

Secondly it could also refer to power outage at the transmitter, I
have
encountered this problem with both Raymarine and Simrad radars. Mostly
it occurs in sailing boats when battery level is getting lower but is
still enough to power the display. Only thing you get is the lost
bearing pulse which means that antenna is not rotating.

But back in to your case, with rough seas loose cables inside
connectors
can cause this problem. Try to pull each wire separately to see wheter
they come out, but better if there is warranty you can let others do
it.

/Jani

One thing to look at very closely, is the way the bearing information
is being generated in the Antenna Unit. In the 2nd and 3rd generation
Furuno Units, the antenna bearing information was generated by a
"Chopper Wheel" with an LED OptoPickup looking thru the Chopper Wheel
holes. This generated pulses, are equated to an angular rotation
of the the antenna.

If the seal leaked on these type units and some of the the Chopper Wheel
Holes filled with moisture, they wouldn't allow the LED InferRed Light
thru to the Pickup and pulses would be missed, and cause the Mechanical
Servo Motor that turned the Yoke coil to slow down and the picture would
rotate backwards.

On 4th and 5th Generation Radars, with Digital Displays, if the Pulse
Stream coming from the Antenna Unit is loosing pulses, the CPU that
Generates the display can't figure out how to display the receive data,
and has an Error Routine that does just what the OP discribes in his
second post. Hitting the "Clear Button" causes the CPU to wait for the
next "Heading Flash" and then start the routine that displays the
Radar Data, from Heading Flash, clockwise at the angular Pulse Rate of
the Bearing Pulses. Should some of those pulses come up missing, and the
next Heading Flash, not come with the right timing, then the CPU will
jump to the Display Error Routine again, and you start all over again.

Sometimes "Older" is better, and the old analog display would at least
give you a picture even if the display went backwards a few degrees per
revolution. Digital Displays can't do that, because of the way the
CPU has to display the data.

Look at the way the Bearing Data is generated, and look for missing
pulses in that system.

Bruce in alaska I know Old Chief Lynn has seen the above senerio....
--
Hey, Bruce, or when the "toilet bowl" filled with water, rust flakes falling
into holes in the encoder disk, or when the encoder disk was rubbing on the
optical pickup and filled some of the holes with a little black plastic
dust, or when the encoder wheel holes were round and were nearly impossible
to align with the optical pickup's beam...... oh, yeah, Bruce.... those
were the days when troubleshooting was easy money (not)!

Old Chief Lynn

Hi Jack,

I currently run the radar in HU since I havnt installed my fluxgate yet.


I can only agree, after reading your post, that the GPS shouldnt have
anything to do with it. The antenna does not know the bearing to the
reflection and thus throws the error message.

Ill try to take apart the dome and check for cables, dirt etc. Any tips
on how the bearing data in Simrads are generated would be greatly
appriciated.


Regards
david

Jack Erbes wrote:
David Rinnan wrote:

Hi Bruce,

Thanks for all the information!

Just to make sure I understand this.. When you say "look at the way
the bearing data is generated" are you then refering to the GPS, in my
case, since I havnt installed a separate compass yet?


It is not about the GPS, he is talking about bearing as in the direction
the radar's rotating radiator or antenna is pointed (relative to the
center line of the boat). That bearing is the direction the radar pulse
was sent to and received from. If that bearing display is off, the
relative bearing to a radar contact from the boat would incorrect.

Does your boat have a flux gate compass? A boat with a radar system
and/or a autopilot really should have a flux gate compass for
determining the boats bearing when not moving. A flux gate compass
knows the bearing at all times (boat moving or not) and sends it to
other devices as a NMEA sentence.

If you do not have a flux gate compass your radar has probably been set
up to use the heading data from the NMEA sentences from the GPS. GPS
headings are only reliable when you are moving, they float around when
you are stopped and do not stay relative to the bow of the boat.

In the above I use heading and bearing as follows:

heading - the direction the boat is moving
bearing - the direction the bow of the boat is pointing

Some people will want to argue about the terms and their use but I'm not
likely to indulge in discussion about it. :) There are many different
definitions and schools of thought on some navigation terms and none of
them are wrong.

Jack

In article ,
David Rinnan wrote:

Hi Bruce,

Thanks for all the information!

Just to make sure I understand this.. When you say "look at the way the
bearing data is generated" are you then refering to the GPS, in my case,
since I havnt installed a separate compass yet?

Regards
david


Bruce in Alaska wrote:
Look at the way the Bearing Data is generated, and look for missing
pulses in that system.

Bruce in alaska I know Old Chief Lynn has seen the above senerio....

No, look at the way the radar antenna bearing information is generated
and sent down to the display unit. This is where your problem, typically
is.

Bruce in alaska
--
add a 2 before @