Last week end we were out all night in a steel cabin cruiser.
The onboard navigation equipment worked well. The handheld Garmin GPS did
not work inside. As for the Magellan Gold it did the job good. My friend
had to stay close to the glass windows. My question is if one has to pick
up an handheld GPS which one will it be?

On Wed, 22 Jun 2005 20:41:41 GMT, "Denis Marier"
wrote:

Last week end we were out all night in a steel cabin cruiser.
The onboard navigation equipment worked well. The handheld Garmin GPS did
not work inside. As for the Magellan Gold it did the job good. My friend
had to stay close to the glass windows. My question is if one has to pick
up an handheld GPS which one will it be?



One that can see through a steel cabin-top?

Brian Whatcott

On Thu, 23 Jun 2005 02:23:33 GMT, Brian Whatcott
wrote:

On Wed, 22 Jun 2005 20:41:41 GMT, "Denis Marier"
wrote:

Last week end we were out all night in a steel cabin cruiser.
The onboard navigation equipment worked well. The handheld Garmin GPS did
not work inside. As for the Magellan Gold it did the job good. My friend
had to stay close to the glass windows. My question is if one has to pick
up an handheld GPS which one will it be?



One that can see through a steel cabin-top?

The fault, dear Brutus, is not in our stars, but in ourselves that we
assume a GPS can work inside a metal box.

Oh, dear...

R.

On Thu, 23 Jun 2005 00:08:12 -0400, rhys wrote:

On Thu, 23 Jun 2005 02:23:33 GMT, Brian Whatcott
wrote:

On Wed, 22 Jun 2005 20:41:41 GMT, "Denis Marier"
wrote:

Last week end we were out all night in a steel cabin cruiser.
The onboard navigation equipment worked well. The handheld Garmin GPS did
not work inside. As for the Magellan Gold it did the job good. My friend
had to stay close to the glass windows. My question is if one has to pick
up an handheld GPS which one will it be?



One that can see through a steel cabin-top?

The fault, dear Brutus, is not in our stars, but in ourselves that we
assume a GPS can work inside a metal box.

Oh, dear...

R.

What he said.....
(external antennas are the stock solution,
but who am I to tell hobbyists?)

Brian Whatcott Altus OK

Brian is correct .....
NO GPS can 'see' through steel or fiberglass, etc. The antenna MUST
have a clear unobstructed view of the satelites .... no wet sail, no
leaves, no roofs, no dodger or bimini, no steel panels.

In article , Denis
Marier wrote:

Last week end we were out all night in a steel cabin cruiser.
The onboard navigation equipment worked well. The handheld Garmin GPS did
not work inside. As for the Magellan Gold it did the job good. My friend
had to stay close to the glass windows. My question is if one has to pick
up an handheld GPS which one will it be?


begin 666 Denis.vcf

You need to get a better GPS if yours won't see through a bimini. My
8 year old GPSMAP 175 works 99% of the time under our hardtop. Every
now and them I'll get a "weak signal" for a few seconds, but its never
enough to affect our navigation.

What I'd like to know is how the nav unit on my wife's new Toyota
stays on track in the Big Dig, 100 feet under ground. It seems to
wander a bit, and then it snaps back into place. Is it cheating by
assuming we stay in the tunnel?




Rich Hampel wrote:
Brian is correct .....
NO GPS can 'see' through steel or fiberglass, etc. The antenna MUST
have a clear unobstructed view of the satelites .... no wet sail, no
leaves, no roofs, no dodger or bimini, no steel panels.

In article , Denis
Marier wrote:


Last week end we were out all night in a steel cabin cruiser.
The onboard navigation equipment worked well. The handheld Garmin GPS did
not work inside. As for the Magellan Gold it did the job good. My friend
had to stay close to the glass windows. My question is if one has to pick
up an handheld GPS which one will it be?


begin 666 Denis.vcf

Your wife's GPS in her car does cheat. When you are underground you
lose all satellite reception and it then assumes that you are
continuing the last course. They call it dead reckoning. Automotive
GPS systems will typically watch your speed on the speedometer and also
your course vectors based upon any turns you have made, and tries to
keep you on course based upon that information. This is an important
feature in cars as many times in the middle of big cities satellite
reception can be very poor or non-existent if you are surrounded by
sky-scrapers. Then every time the GPS gains satellite reception back
it will correct itself again, the snapping back you see.

Slacker

Rich Hampel wrote:
Brian is correct .....
NO GPS can 'see' through steel or fiberglass, etc. The antenna MUST
have a clear unobstructed view of the satelites .... no wet sail, no
leaves, no roofs, no dodger or bimini, no steel panels.

In article , Denis
Marier wrote:


Last week end we were out all night in a steel cabin cruiser.
The onboard navigation equipment worked well. The handheld Garmin GPS did
not work inside. As for the Magellan Gold it did the job good. My friend
had to stay close to the glass windows. My question is if one has to pick
up an handheld GPS which one will it be?


begin 666 Denis.vcf


When our skipper bought a Mirage 33 sailboat, it came with a Garmin 75
(I believe a 1993 model) That thing was expensive in it's day...about
$1k CDN but you could unscrew the stubby antenna and hook up the unit to
a cable attached to a bigger antenna mounted on the stern rail while you
were in the cabin.

Your GPS works underground? Amazing. Normally they shouldnt work
beneath any water saturated soil. I know they dont work in most caves.

Don White wrote in
:

When our skipper bought a Mirage 33 sailboat, it came with a Garmin 75
(I believe a 1993 model) That thing was expensive in it's day...about
$1k CDN but you could unscrew the stubby antenna and hook up the unit to
a cable attached to a bigger antenna mounted on the stern rail while you
were in the cabin.



The "antenna" in the Garmin 75 series GPS wasn't just an antenna. DC power
is fed up the coax from the 75 to a microwave amplifier and downconverter
which makes a much-lower-frequency IF signal, properly amplified, before it
is fed down the same coax to the 75. There used to be an Xray picture of
the Garmin 75's grey plastic antenna on the net and I stored it showing the
helical dipole array actually made of flexible printed circuit board and
wrapped into a cylinder inside the plastic radome, but it is off the net,
google couldn't find it and my hard drive is long gone....

Because the RF between this antenna/converter and the GPS75 is a lower
intermediate frequency, not the 2400 Mhz microwaves from the birds, any
coaxial extension cord with a BNC male on one end and BNC female connector
on the other works great to move the antenna away from the GPS75, Same
old, cheap RG-58 from RatShack works fine.

Just make SURE the coax center conductor is ISOLATED from its shield or it
will burn up the tuning circuitry in the GPS-75 from the shorting of its
tuning voltage output!

I programmed a mint condition GPS75 for a visiting old sailor single-
handing a 28' sloop on our dock just yesterday! He'd had it for years and
NEVER USED IT! I gave him a little GPS/Garmin 75 school from what I could
remember about mine...(c;

--
Larry

You know you've had a rough night when you wake up and you're outlined in
chalk.