Using external antennas on a hand held?

I see there are external antennas for hand held receivers available to use
in motor vehicles. Some mount on the outside of the vehicle and some use
suction cups that stick to the inside of the windshield.



Some Garmin GPS unit product information says that model is a
"High-sensitivity receiver". And, from many reviews I have read from users
who have high-sensitivity on their receivers are very pleased with the
reception they get, compared to older versions.



One of the technicians at Garmin told me that the hand held high-sensitivity
models would not need an external antenna when using it inside a motor
vehicle.



I guess if the receiver is sitting high enough inside the vehicle (on the
dashboard) it could work just fine without an antenna.



Anyone think it worth using an external antenna on a hand held in a vehicle?

Someone claims to be using a Nuvi that he has mounted to the center
console between the seats, under the radio, in his Prius--and it works
fine.

Alas, that's where my XM Radio is, so I can't test that theory.
Oh--also, I don't have a Nuvi.

Elmo P. Shagnasty wrote:

Does the car have a moon/sun roof? The unit needs a look at the sky,
not a PERFECT view. If it works at all, the accuracy should be good
enough for navigation. I have a external antenna for my 2610 - buried
in the dash compartment - and routinely obtain 7' accuracy. Do I need
7' or would 20' or 30' be accurate enough? Certainly.

Back to topic. If you have a moon/sun roof you should be good to go.
The inner curtain or liner for the moon/sun roof is plastic or
fibreglass and is transparent to the GPS. I've used my 2610 or Quest
with their built-in antenna with the unit sitting on the passenger seat
or center console on my Corvette. Removable hardtop is fibreglass and
the units "see" right through it.

No, the Prius by definition does not have any such thing.

It depends on the individual circumstances. Even with the older lower
sensitivity Garmins I rarely use my external antenna when I use the
units inside my car, but it does come in handy when in cities like
Manhattan where the buildings limit the skyview and the receiver needs
as much signal as possible. There are also cars with metallic
coatings on the windshield that block the signals and in that case an
external antenna would be desirable even with the higher sensitivity
models. Using the external is also nice if several people in the car
will be looking at the handheld screen since it eliminates any
concerns about the orientation or nearness to a window.

Since my Gilsson external antenna cost less than $20 I feel it was a
worthwhile purchase even though I don't use it most of the time.