Bruce in alaska wrote in news:fast-EB795C.10155321012008
@netnews.worldnet.att.net:

John's
Point, was that the Radar Transponder MUST be mounted Clearly OUTSIDE
the Vertical Beamwidth of the Onboard Radar, so as to not be triggered
by the operation of the onboard Radar. This is correct

Noone is going to run a radar transponder and radar on the same boat. That
transponder is going to go berserk re-radiating your own radar. There's
all kinds of crazy side lobes on the ****ty PC board antenna on any radome
array. The lobes don't have a lot of power, but sure more than enough
power to set off a transponder, even if you put the damned antenna in the
BILGE!

What a crazy idea....

On Tue, 22 Jan 2008 06:19:37 +0000, larry wrote in
:

Bruce in alaska wrote in news:fast-EB795C.10155321012008
:

John's
Point, was that the Radar Transponder MUST be mounted Clearly OUTSIDE
the Vertical Beamwidth of the Onboard Radar, so as to not be triggered
by the operation of the onboard Radar. This is correct

Noone is going to run a radar transponder and radar on the same boat. That
transponder is going to go berserk re-radiating your own radar. There's
all kinds of crazy side lobes on the ****ty PC board antenna on any radome
array. The lobes don't have a lot of power, but sure more than enough
power to set off a transponder, even if you put the damned antenna in the
BILGE!

What a crazy idea....

Not at all. They serve different purposes, and are complementary.

--
Best regards,
John Navas http:/navasgroup.com

In article ,
larry wrote:
....
Noone is going to run a radar transponder and radar on the same boat.

Is it?

... but sure more than enough
power to set off a transponder, even if you put the damned antenna in the
BILGE!

Of course, but so what. I cannot see anything with my radar up to some
15 metres anyway (assuming 50 ns pulse). The key is if it still responds
to other radars.

What a crazy idea....

Why? The radar expands what I see, and the transponder expands, what
others with a radar see.

I have seen how unreliable echos from glass fibre reinforced polyester
boats are (and how unreliable echos at least smaller passive radar
reflectors of the 90° aluminum sheets type give on quiet waters).

Small wonder aircraft all have a transponder.

Marc

--
remove bye and from mercial to get valid e-mail
http://www.heusser.com

Marc Heusser d wrote in
:

I have seen how unreliable echos from glass fibre reinforced polyester
boats are (and how unreliable echos at least smaller passive radar
reflectors of the 90ø aluminum sheets type give on quiet waters).



If you're going to buy anything to make you a big target on the SHIPS and
large yachts....buy an AIS TRANSPONDER, which makes you as big as an
aircraft carrier.

All ship over 300 gross tons now have full AIS aboard, as do the big
yachts, to make them look big.

Every boat that leaves the harbor should be AIS equipped, now.

Of course, every harbor should have:
http://www.aisliverpool.org.uk/
too. It'll come, eventually.

larry wrote:
Marc Heusser d wrote in
:

I have seen how unreliable echos from glass fibre reinforced polyester
boats are (and how unreliable echos at least smaller passive radar
reflectors of the 90ø aluminum sheets type give on quiet waters).



If you're going to buy anything to make you a big target on the SHIPS and
large yachts....buy an AIS TRANSPONDER, which makes you as big as an
aircraft carrier.

All ship over 300 gross tons now have full AIS aboard, as do the big
yachts, to make them look big.


I'm still waiting to upgrade my AIS receiver for a
transponder. At least I can see and identify a threat and
call by name on VHF.

From 'The Pilot' the magazine of the United Kingdom
Maritime Pilots' Association, quoting a working harbour pilot:
"With respect to the type of equipment installed, the
overwhelming majority of vessels are fitted with the minimum
required to comply with carriage regulations! These are
small alpha numeric displays which at the absolute basic
level have to display at least three targets. I have seen
such minimal three line units on ships and for all practical
purposes they are totally useless. Other systems cram a list
of many targets into the small display (typically 9cm x
12cm) which renders them illegible and again these are
totally useless.
It is of extreme importance to the Class B user to be
aware that there is no statutory requirement for SOLAS
vessels to be able to display AIS targets on a screen merely
a requirement to provide a simple alphanumeric Minimum
Keyboard and Display (MKD). To meet the minimum requirements
this display need show no more than three ships at any one
time detailing bearing, range and name of ship. Therefore
Class B users must understand that their vessel may not be
appearing as a 'bright beacon' on the displays of the
majority of SOLAS vessels. Although IMO requires all new
radars fitted after 1 July 2008 to have good AIS display
capabilities, existing radars will not have to be upgraded
and so it will be many years before AIS data can be
effectively used for navigation on many SOLAS vessels."

BrianH wrote in news:1d379$47960e55$50dbe397$1297
@news.hispeed.ch:

I'm still waiting to upgrade my AIS receiver for a
transponder. At least I can see and identify a threat and
call by name on VHF.


What I always find amusing, out at sea, is the reluctance of the yachties
to simply TALK to the ships. It's as if that SeaLand containership were
full of pirates and they're afraid of being attacked or ****ing off the
bored-to-death mate at the helm.

I had a first mate on a freighter I was talking to on Ch 13 a hundred miles
off Savannah try to trade me for the 35' Endeavour sloop I was driving. We
decided we couldn't dock a 400 footer at our little slip at Ashley Marina,
though it would have made the marina just thrilled if I stopped by the
diesel dock....just fueling the generators!

They're really nice guys and WANT you to call 'em and tell them at least
where you are and what you are. "Can you flash your searchlight at me?",
many have asked me. We got a monster handheld. "Ah, now I see where you
are. I can hardly make out your masthead light from here." I was 6 miles
away, so I guess that was OK. The searchlight made us a much bigger
target.

TALK TO THEM, dammit! There's just times when being a sailing hermit is
stupid!

larry wrote:
BrianH wrote in news:1d379$47960e55$50dbe397$1297
@news.hispeed.ch:

I'm still waiting to upgrade my AIS receiver for a
transponder. At least I can see and identify a threat and
call by name on VHF.


What I always find amusing, out at sea, is the reluctance of the yachties
to simply TALK to the ships. It's as if that SeaLand containership were
full of pirates and they're afraid of being attacked or ****ing off the
bored-to-death mate at the helm.

I've been recently following a few MAIB (UK) yacht/ship
collision reports and I am mystified why the yacht failed to
attempt to use a serviceable VHF radio to warn that they
were being run down. The much-publicised loss of the Ouzo
off the Isle of Wight in 2006 is a classic example. This is
especially so when compared to the banal chat I often hear
from many yachts calling their buddies.

On Tue, 22 Jan 2008 20:01:06 +0100, BrianH wrote in
:

larry wrote:
BrianH wrote in news:1d379$47960e55$50dbe397$1297
@news.hispeed.ch:

I'm still waiting to upgrade my AIS receiver for a
transponder. At least I can see and identify a threat and
call by name on VHF.

What I always find amusing, out at sea, is the reluctance of the yachties
to simply TALK to the ships. It's as if that SeaLand containership were
full of pirates and they're afraid of being attacked or ****ing off the
bored-to-death mate at the helm.

I've been recently following a few MAIB (UK) yacht/ship
collision reports and I am mystified why the yacht failed to
attempt to use a serviceable VHF radio to warn that they
were being run down. The much-publicised loss of the Ouzo
off the Isle of Wight in 2006 is a classic example. This is
especially so when compared to the banal chat I often hear
from many yachts calling their buddies.

Many mariners have no idea what channel to use.

--
Best regards,
John Navas http:/navasgroup.com

BrianH wrote in news:a110e$47963cb8$50dbe397$5452
@news.hispeed.ch:

I've been recently following a few MAIB (UK) yacht/ship
collision reports and I am mystified why the yacht failed to
attempt to use a serviceable VHF radio to warn that they
were being run down. The much-publicised loss of the Ouzo
off the Isle of Wight in 2006 is a classic example. This is
especially so when compared to the banal chat I often hear
from many yachts calling their buddies.



You'd think the ship was from another galaxy the way some yachties are
afraid to talk to them. It's crazy.

larry wrote in news:Xns9A2D69494A46Bnoonehomecom@
208.49.80.253:

All ship over 300 gross tons now have full AIS aboard, as do the big
yachts, to make them look big.


Name: Grand Esmeralda
MMSI: 636012671 [LR]
IMO: 8920062
Callsign: A8GX9
Speed/Dir: 14.2 kts / 278° W
Status: Underway
Dest: Mobile,Alabama
ETA: Feb06 06:00
Type: Cargo (70)
Size: 225m x 32m x 7.3m
Received: 15:17:50 22 Jan 08 GMT

Just snapped his picture on the webpage. Long trip to Mobile from
Liverpool. He just left.

Not only would the mate driving that tanker know you were there....He'd
know a lot about you, too, and his computer would make sure he didn't
collide with you unless you did something really stupid.

We could even call him with his callsign...