On Sun, 23 Nov 2003 17:48:11 +0000, Jack Dale wrote:

On Sun, 23 Nov 2003 09:07:50 -0800, "Lloyd Sumpter" wrote:

Hi,

Thinking of getting radar for Far Cove, mainly for this planned trip to
WCVI,
which has lots of fog.

Now, I've survived 20+ years of sailing Georgia Strait, etc. without radar.
If it's really foggy, I just stay put. If I venture out, I use several nav aids
including GPS to determine my position, blow my horn and listen.

I'm thinking that, even WITH radar, I wouldn't venture out in unfamiliar
waters in dense fog. And if I was out and the fog rolled in on me, I would
think that GPS, sounder and a good chart would be better to find that anchorage
than radar, assuming I could see at least 100 ft or so.

Comments?

I agree that a GPS, sounder and good charts are necessary. But given a choice
between a chart plotter and radar, I would go with radar. The major reason is
that radar will provide an indication of what is around me, mainly other
vessels. In Juan de Fuca, that is a big consideration.

Once you spend some time with radar you can interpret the screen quite easily.
This would permit you to find the anchorage. Additionally, the racon buoys
permit an great radar fix.


Thanks for the input!

I didn't mean an either/or scenario - it's more like: if I have
GPS/sounder/charts, what extra does radar give me? And of course, it DOES show
vessels, etc., but I'm thinking that's mainly a consideration in fog, and I'm
wondering if I would venture out even if I HAD radar (after all, what if the
radar quits?).

So is radar worth it for the 1 day a year I MIGHT venture out in fog?

Or, to put it differently, what ELSE is radar good for? Can I use it to
determine if a freighter 10 miles away is on a collision course with me? Do
others normally run with radar on, even if it's clear? Why?

Lloyd Sumpter
"Far Cove" Catalina 36

Lloyd Sumpter wrote:
On Sun, 23 Nov 2003 17:48:11 +0000, Jack Dale wrote:


On Sun, 23 Nov 2003 09:07:50 -0800, "Lloyd Sumpter" wrote:


Hi,

Thinking of getting radar for Far Cove, mainly for this planned trip to
WCVI,
which has lots of fog.

Now, I've survived 20+ years of sailing Georgia Strait, etc. without radar.
If it's really foggy, I just stay put. If I venture out, I use several nav aids
including GPS to determine my position, blow my horn and listen.

I'm thinking that, even WITH radar, I wouldn't venture out in unfamiliar
waters in dense fog. And if I was out and the fog rolled in on me, I would
think that GPS, sounder and a good chart would be better to find that anchorage
than radar, assuming I could see at least 100 ft or so.

Comments?

I agree that a GPS, sounder and good charts are necessary. But given a choice
between a chart plotter and radar, I would go with radar. The major reason is
that radar will provide an indication of what is around me, mainly other
vessels. In Juan de Fuca, that is a big consideration.

Once you spend some time with radar you can interpret the screen quite easily.
This would permit you to find the anchorage. Additionally, the racon buoys
permit an great radar fix.



Thanks for the input!

I didn't mean an either/or scenario - it's more like: if I have
GPS/sounder/charts, what extra does radar give me? And of course, it DOES show
vessels, etc., but I'm thinking that's mainly a consideration in fog, and I'm
wondering if I would venture out even if I HAD radar (after all, what if the
radar quits?).

So is radar worth it for the 1 day a year I MIGHT venture out in fog?

Or, to put it differently, what ELSE is radar good for? Can I use it to
determine if a freighter 10 miles away is on a collision course with me? Do
others normally run with radar on, even if it's clear? Why?

Lloyd Sumpter
"Far Cove" Catalina 36


Only you can answer the first question. As for uses ..... any collision
avoidance situation, be it collision course or just wanting to figure
how far you'll miss by, and what's the most dangerous target.
Navigation ..... eyeball and exact, has many uses, plus docking in fog,
maintaining a quick anchor watch .... too numerous.
Problem you might have will be with power, to make as much use of it as
you potentially could.

Lloyd Sumpter wrote:
On Sun, 23 Nov 2003 17:48:11 +0000, Jack Dale wrote:


On Sun, 23 Nov 2003 09:07:50 -0800, "Lloyd Sumpter" wrote:


Hi,

Thinking of getting radar for Far Cove, mainly for this planned trip to
WCVI,
which has lots of fog.

Now, I've survived 20+ years of sailing Georgia Strait, etc. without radar.
If it's really foggy, I just stay put. If I venture out, I use several nav aids
including GPS to determine my position, blow my horn and listen.

I'm thinking that, even WITH radar, I wouldn't venture out in unfamiliar
waters in dense fog. And if I was out and the fog rolled in on me, I would
think that GPS, sounder and a good chart would be better to find that anchorage
than radar, assuming I could see at least 100 ft or so.

Comments?

I agree that a GPS, sounder and good charts are necessary. But given a choice
between a chart plotter and radar, I would go with radar. The major reason is
that radar will provide an indication of what is around me, mainly other
vessels. In Juan de Fuca, that is a big consideration.

Once you spend some time with radar you can interpret the screen quite easily.
This would permit you to find the anchorage. Additionally, the racon buoys
permit an great radar fix.



Thanks for the input!

I didn't mean an either/or scenario - it's more like: if I have
GPS/sounder/charts, what extra does radar give me? And of course, it DOES show
vessels, etc., but I'm thinking that's mainly a consideration in fog, and I'm
wondering if I would venture out even if I HAD radar (after all, what if the
radar quits?).

So is radar worth it for the 1 day a year I MIGHT venture out in fog?

Or, to put it differently, what ELSE is radar good for? Can I use it to
determine if a freighter 10 miles away is on a collision course with me? Do
others normally run with radar on, even if it's clear? Why?

Lloyd Sumpter
"Far Cove" Catalina 36


Only you can answer the first question. As for uses ..... any collision
avoidance situation, be it collision course or just wanting to figure
how far you'll miss by, and what's the most dangerous target.
Navigation ..... eyeball and exact, has many uses, plus docking in fog,
maintaining a quick anchor watch .... too numerous.
Problem you might have will be with power, to make as much use of it as
you potentially could.

"Lloyd Sumpter" wrote in message
...
So is radar worth it for the 1 day a year I MIGHT venture out in fog?

Or, to put it differently, what ELSE is radar good for? Can I use it to
determine if a freighter 10 miles away is on a collision course with me? Do
others normally run with radar on, even if it's clear? Why?


I turn on the radar whenever I'm outside my home water (Boston Harbor) or if the
conditions are ripe for fog. I often keep it in standby to save power and
magnetron time (they do wear out), but I make a point of using for while on
every passage. If there's ship in the distance, I try to work out a CPA
(Closest Point of Approach). If I'm "racing" a boat, I use it to compute the
other's speed. And if there's t-storms or squalls about, its fun to track them.

One problem with radar is that it does take practice - especially to use it
properly in the thick stuff. If you're thinking you can mount the screen down
below and turn it on once a year, you may be better off not having it.

--
-jeff
"Constant Vigilance!" - Frances W. Wright

In article ,
"Jeff Morris" wrote:

I often keep it in standby to save power and
magnetron time (they do wear out)

Just a point of note here. Leaving the radar in standby on most
civilian consumer radars does not save anything on Magnitron
Time. What wears out is the Filiment (heater) and that is
always ON whenever the Powersupply is on, even in Standby Mode.
To convise yourself of this, do this simple test. When you first
"Fire up" your radar, there is a timer that allows the Magnitron
to "Heat up and Stabalize", usually for three (3) minutes or so.
After that initial "Warm up Period", when going from "Standby"
to "Operate" does your radar require another "Warm up Period"?
If so, then you are correct on your Magnitron time statement.(Not very
likely to be this way) If not, then then "Standby" only save you
Transmit Power, and that's not really very much in most cases.
Most modern Magnitrons have between 2000 and 4000 hours of Service
Life and that is Filiment Life, really.

Bruce in alaska
--
add a 2 before @

I was curious about this issue, so I sent a query to RayMarine a couple of years
ago. Here's what I asked, with reference to a SL72 radar:

I am curious as to the lifetime of the magnetron, or any other related
components. I often leave the radar in Standby Mode to save power and magnetron
wear, but have been advised that the magnetron is heated in standby and thus can
wear out. How many hours use might I expect, and will standby reduce wear?

Here's the response I received:

The magnetron is being heated anytime the radar is in standby. This will not,
however, significantly impact the life of the magnetron. Actual transmit time
is what really wears out the magnetron. If you are really concerned about it,
you can turn off the radar scanner by holding the CLEAR key in for about 10
seconds. this leaves the display energized, and available for the display of
chart or data. You can turn the scanner back on at anytime by tapping the POWER
key while on the radar mode. You will have to wait 70 seconds for the warmup
sequence to complete. In an EMERGENCY you can always bypass the magnetron
warm-up by holding in the ENTER key for 5 seconds.

For systems installed on recreational vessels, we usually see upwards of 12,000
hours of magnetron operation. That averages out to about 4 years of heavy use.
In many cases, however, we see magnetrons last 10 years or more.

Jim McGowan
Senior Product Support Engineer

Raymarine Inc.
http://www.raymarine.com




By the way, the spec for my SL70 dome says that the power usage is 28 Watts
transmitting, 9 Watts standby. That's a pretty significant difference.

-jeff


"Bruce in Alaska" wrote
"Jeff Morris" wrote:
I often keep it in standby to save power and
magnetron time (they do wear out)

Just a point of note here. Leaving the radar in standby on most
civilian consumer radars does not save anything on Magnitron
Time. What wears out is the Filiment (heater) and that is
always ON whenever the Powersupply is on, even in Standby Mode.
To convise yourself of this, do this simple test. When you first
"Fire up" your radar, there is a timer that allows the Magnitron
to "Heat up and Stabalize", usually for three (3) minutes or so.
After that initial "Warm up Period", when going from "Standby"
to "Operate" does your radar require another "Warm up Period"?
If so, then you are correct on your Magnitron time statement.(Not very
likely to be this way) If not, then then "Standby" only save you
Transmit Power, and that's not really very much in most cases.
Most modern Magnitrons have between 2000 and 4000 hours of Service
Life and that is Filiment Life, really.

Bruce in alaska
--
add a 2 before @

On Mon, 24 Nov 2003 16:01:11 -0500, "Jeff Morris"
wrote:

I was curious about this issue, so I sent a query to RayMarine a couple of years
ago. Here's what I asked, with reference to a SL72 radar:
//
The magnetron is being heated anytime the radar is in standby. This will not,
however, significantly impact the life of the magnetron. Actual transmit time
is what really wears out the magnetron. ///
Jim McGowan
Senior Product Support Engineer

Raymarine Inc.
http://www.raymarine.com

-jeff

In case you're wondering....
the cathode coating 'wears out' by electron emission
from the 'dull emitter' surface so that its emissivity drops.

Brian W

On Mon, 24 Nov 2003 16:01:11 -0500, "Jeff Morris"
wrote:

I was curious about this issue, so I sent a query to RayMarine a couple of years
ago. Here's what I asked, with reference to a SL72 radar:
//
The magnetron is being heated anytime the radar is in standby. This will not,
however, significantly impact the life of the magnetron. Actual transmit time
is what really wears out the magnetron. ///
Jim McGowan
Senior Product Support Engineer

Raymarine Inc.
http://www.raymarine.com

-jeff

In case you're wondering....
the cathode coating 'wears out' by electron emission
from the 'dull emitter' surface so that its emissivity drops.

Brian W

I was curious about this issue, so I sent a query to RayMarine a couple of years
ago. Here's what I asked, with reference to a SL72 radar:

I am curious as to the lifetime of the magnetron, or any other related
components. I often leave the radar in Standby Mode to save power and magnetron
wear, but have been advised that the magnetron is heated in standby and thus can
wear out. How many hours use might I expect, and will standby reduce wear?

Here's the response I received:

The magnetron is being heated anytime the radar is in standby. This will not,
however, significantly impact the life of the magnetron. Actual transmit time
is what really wears out the magnetron. If you are really concerned about it,
you can turn off the radar scanner by holding the CLEAR key in for about 10
seconds. this leaves the display energized, and available for the display of
chart or data. You can turn the scanner back on at anytime by tapping the POWER
key while on the radar mode. You will have to wait 70 seconds for the warmup
sequence to complete. In an EMERGENCY you can always bypass the magnetron
warm-up by holding in the ENTER key for 5 seconds.

For systems installed on recreational vessels, we usually see upwards of 12,000
hours of magnetron operation. That averages out to about 4 years of heavy use.
In many cases, however, we see magnetrons last 10 years or more.

Jim McGowan
Senior Product Support Engineer

Raymarine Inc.
http://www.raymarine.com




By the way, the spec for my SL70 dome says that the power usage is 28 Watts
transmitting, 9 Watts standby. That's a pretty significant difference.

-jeff


"Bruce in Alaska" wrote
"Jeff Morris" wrote:
I often keep it in standby to save power and
magnetron time (they do wear out)

Just a point of note here. Leaving the radar in standby on most
civilian consumer radars does not save anything on Magnitron
Time. What wears out is the Filiment (heater) and that is
always ON whenever the Powersupply is on, even in Standby Mode.
To convise yourself of this, do this simple test. When you first
"Fire up" your radar, there is a timer that allows the Magnitron
to "Heat up and Stabalize", usually for three (3) minutes or so.
After that initial "Warm up Period", when going from "Standby"
to "Operate" does your radar require another "Warm up Period"?
If so, then you are correct on your Magnitron time statement.(Not very
likely to be this way) If not, then then "Standby" only save you
Transmit Power, and that's not really very much in most cases.
Most modern Magnitrons have between 2000 and 4000 hours of Service
Life and that is Filiment Life, really.

Bruce in alaska
--
add a 2 before @

On Mon, 24 Nov 2003 20:30:38 GMT, Bruce in Alaska
wrote (with possible editing):

In article ,
"Jeff Morris" wrote:

I often keep it in standby to save power and
magnetron time (they do wear out)

Just a point of note here. Leaving the radar in standby on most
civilian consumer radars does not save anything on Magnitron
Time. What wears out is the Filiment (heater) and that is
always ON whenever the Powersupply is on, even in Standby Mode.
To convise yourself of this, do this simple test. When you first
"Fire up" your radar, there is a timer that allows the Magnitron
to "Heat up and Stabalize", usually for three (3) minutes or so.
After that initial "Warm up Period", when going from "Standby"
to "Operate" does your radar require another "Warm up Period"?
If so, then you are correct on your Magnitron time statement.(Not very
likely to be this way) If not, then then "Standby" only save you
Transmit Power, and that's not really very much in most cases.
Most modern Magnitrons have between 2000 and 4000 hours of Service
Life and that is Filiment Life, really.

Bruce in alaska

No flame, Bruce, but what normally wears out a magnetron is depletion
of the cathode. The cathode is heated by the filament so that it will
emit electrons. As the tube ages, its ability to emit them decreases.
As radar operates in pulsed service, the tubes should last a good deal
longer. Often, a magnetron which is substantially dead, will still
"light up" just like the final output tubes in transmitters.
--

Larry
Email to rapp at lmr dot com