|
|
|
|
|||||
|
||||||
From: Faure, Marin (no email)
Date: Wed Nov 02 2005 - 20:36:35 EST
>Brent wrote- My Loran would not home in on a position after 30 minutes.
If anyone in the Anacortes, WA area still uses Loran please check yours
and let me know if mine has finally bit the dust or the Loran
transmitters are not working.
We have a Furuno Loran-C on our GB and we still use it as a backup to
the GPS C-MapNT chart plotter. We turn the Loran on every time we go
out, which means we had it on a week and a half ago (Oct. 22-24) when we
cruised from Bellingham to Sucia and back. The signals were fine during
that time period.
I don't know how your Loran unit works, but the late-80s Raytheon unit
we have on our other boat requires an approximate position to be entered
the first time it's turned on after having been moved a significant
distance. For example when we trailer the boat from Seattle to the
north end of Vancouver Island. This approximate position tells the
unit what chain to tune to and probably other signal information as
well. If I do not get the approximate position relatively close it will
not tune itself properly or display a position no matter how long I
leave it on. I don't know if the Furuno on our GB has that same
requirement--- we haven't moved the boat very far without its being on,
and I don't remember if I had to enter an approximate position when we
turned it on after the boat was trucked up from California in 1998.
Anyway, if your unit has this requirement and it's somehow lost its
basic location--- the internal battery has died (if it has one) or
something else has happened to confuse it--- you may need to re-enter
your basic position there in Anacortes.
If they have done anything recently to improve the accuracy of Loran-C
it hasn't made itself obvious on our set. The lat/long is the same
amount off when compared to the GPS as it's always been, but Loran-C has
been that way ever since we started using it on our first boat back in
1987. It's my understanding that the timing of the Loran signals can be
affected by the terrain they pass over. In this area with all the
islands and bodies of water, the speed of the signals is affected just
enough to knock the position accuracy off by a sometimes-significant
amount depending on your location in the islands. The good news is the
error is consistent. So if you enter a Loran-C waypoint with the boat
physically at the waypoint, the Loran will return you to that exact spot
every single time even though the lat/long displayed on the instrument
will not be your actual position on the planet. The signal error only
becomes a problem if you use coordinates you plotted on a chart to input
the position of a waypoint.
There are still some commercial fisherman around who prefer Loran-C to
GPS because even with the skew removed from GPS and things like DGPS,
they claim Loran-C will do a better job of taking them right to a crab
pot buoy in the kind of heavy fog that makes a buoy invisible if you're
only 20 or 30 feet away. Of course this may be just a case of them not
wanting to change from what they're used to....
But I like Loran-C despite its limitations. We don't cancel a trip when
it's foggy, so we've put our commonly-traveled routes into the Loran so
we have a backup navigation system in case the GPS plotter quits. We
also have a handheld C-MapNT GPS plotter with the same routes, but it
sometimes ends up on the other boat. So the Loran-C is a nice thing to
have along.
______________________________
C. Marin Faure
GB36-403 "La Perouse"
Bellingham, Washington
[demime 1.01d removed an attachment of type application/ms-tnef which had a name of winmail.dat]
_______________________________________________
http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering
To unsubscribe send email to
with the word
UNSUBSCRIBE and nothing else in the subject or body of the message.
Trawlers & Trawlering and T&T are trademarks of Water World
Productions. Unauthorized use is prohibited.
|