Thanks for the clarifications, guys. So, to sum up, if you have a
mizzen, it's a great spot for a radar with little downside unless you
think you need the height of the mainmast, but then you may foul an
overlapping genoa.

Does that sum it up?

Just remember that a radar sends out radio waves, and any metal in front
of it will cause part of your radar signal to be bounced back to your
radar. The metal mast and rigging may not obscure your radar display
(an empty "shadow area"), but some of that energy will be bounced right
back and can either cause interference or even damage to your radar's
receiver. All the more reason not to use a 4 kw system.

Admittedly, any installation an a sailboat would be a compromise, just
as long as you're aware of whatever the limitations/consequences might be.


Now, if I can just figure out how to put a windvane AND davits behind
a mizzen mast....G


The windvane should go high on the mizzen, as on my friends boat:
http://www.sv-loki.com/Moonshadow/Pg22.jpg

Note that the davits are behind, and also serve as a good place for
solar panels.

Wind -vane- or wind -generator-? The pictures show what I'd call a
"wind generator". Mounting a wind vane self steering system is a whole
different kind of animal. Which is it you need help with?

Paul

=---------------------------=
Renewontime
A FREE email reminder service for licensed mariners
http://www.renewontime.com
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renewontime dot com wrote:
Thanks for the clarifications, guys. So, to sum up, if you have a
mizzen, it's a great spot for a radar with little downside unless you
think you need the height of the mainmast, but then you may foul an
overlapping genoa.

Does that sum it up?


Just remember that a radar sends out radio waves, and any metal in front
of it will cause part of your radar signal to be bounced back to your
radar. The metal mast and rigging may not obscure your radar display
(an empty "shadow area"), but some of that energy will be bounced right
back and can either cause interference or even damage to your radar's
receiver. All the more reason not to use a 4 kw system.

What??? Are you claiming its dangerous to mount a radar on the mast?
Actually, most masts will reflect the energy away. RayMarine advises to
put a block of wood between the mast and dome if there's interference on
the screen, but I've had several (including a large Nonsuch mast) and
never seen a problem. I don't see how there would be a problem with the
main mast interfering with a mizzen mounted dome.

In article ,
Jeff Morris wrote:

renewontime dot com wrote:
Thanks for the clarifications, guys. So, to sum up, if you have a
mizzen, it's a great spot for a radar with little downside unless you
think you need the height of the mainmast, but then you may foul an
overlapping genoa.

Does that sum it up?


Just remember that a radar sends out radio waves, and any metal in front
of it will cause part of your radar signal to be bounced back to your
radar. The metal mast and rigging may not obscure your radar display
(an empty "shadow area"), but some of that energy will be bounced right
back and can either cause interference or even damage to your radar's
receiver. All the more reason not to use a 4 kw system.

What??? Are you claiming its dangerous to mount a radar on the mast?
Actually, most masts will reflect the energy away. RayMarine advises to
put a block of wood between the mast and dome if there's interference on
the screen, but I've had several (including a large Nonsuch mast) and
never seen a problem. I don't see how there would be a problem with the
main mast interfering with a mizzen mounted dome.

Naw, don't worry about such stuff, it is not factual information anyway.


Read Meinhert, and Bruce in alaska's posts for the FACTS.......


Me

"renewontime dot com" wrote in message
...
Just remember that a radar sends out radio waves, and any metal in front
of it will cause part of your radar signal to be bounced back to your
radar. The metal mast and rigging may not obscure your radar display
(an empty "shadow area"), but some of that energy will be bounced right
back and can either cause interference or even damage to your radar's
receiver. All the more reason not to use a 4 kw system.

No it won't. When the radar is transmitting, the receiver is shut off or the
path from the antenna to the receiver is blocked. When the tranmission
stops, the receiver is switched on again but not immediately. So the first
strong echos from very nearby objects will not reach the received. Apart
from that, the receivers' sensitivity is increased from almost nothing to
full gradually to compensate for the weaker echos from longer distances.

Meindert

In article ,
renewontime dot com wrote:

The metal mast and rigging may not obscure your radar display
(an empty "shadow area"), but some of that energy will be bounced right
back and can either cause interference or even damage to your radar's
receiver. All the more reason not to use a 4 kw system.

Nope, not even close to being true. The radar receiver has a Range Gate
built into the frontend that does not enable the receiver to see
anything untill after the transmitted pulse has long since left the
antenna. The Range Gate timing is what sets the Minimum Radar Range
of the radar and is usually set so that the minimum range is on the
order of 50 or 75 yards. Any reflected Transmitter Pulse will have long
since traveled out to the mast or reflective surface aboard the same
vessel and returned long before the Range Gate opened up the receiver
frontend, looking for a return signal.
Your thinking of the Second Generation Radars with RadioActive TR Cells,
that when hear the end of their useful life just opened up and allowed
the Transmitter Pulse to reach the Microwave Diode Crystals, and destroy
them. All third generation and later radars, use a different Range Gate
System, and are not subject to this type of problem. Any return signal
from farther than 75 yards will be so attenuated in power density, that
it can't hurt the receiver frontend. Inverse Square Law prevails in the
RF World. Now the above is all well and good, but does not take in to
account that when rafted up to another vessel which is operating it's
Radar and your radar is operating as well, and the two antenna's point
exactly at each other for a few cycles of their transmitters, that
damage couldn't happen to the recivers from the others transmitter.
the probubility of this is low, but still significant. Never allow
a rafted vessel to operate a radar, when your antenna is pointed toward
theirs.


Bruce in alaska
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add a 2 before @