How to filter out the FM radio static on the Garmin Nuvi 6xx

On Wed, 05 Sep 2007 09:19:34 -0400, Jack Erbes wrote:


I never read a gps review that told the truth. None. Nada. Zip.

They all lie because they are PAID by the gps manufacturers.

For example, read the gpsreview for the nuvi and it says the FM transmitter
is great. HA!!!!!! What a joke. Nobody has ever gotten the FM transmitter
on a nuvi to transmit anything but static. It's useless.

Worse than that, it's a marketing gimmick - like the "simulation mode" and
the hokey mp3 player. Sure, if you like listening to tinny mono music from
a point on your dashboard it's ok as a telephone speaker - but as a "music
device", it's useless.

But you'll never see a gpsreview that tells you like it is because they are
all in the pocket of the manufacturer, garmin in this case but the others
are no better.

My advice? Don't pay a cent for the nuvi "FM transmitter" and certainly
don't even try to use it. Then, you'll be happy.

snip


A little over the top perhaps, but the fm transmitter in the 660 is worse
than any of the aftermarket ones I have used in the past with generations
of mp3 players. But it makes for great marketing...

Has anyone added an antenna to the Nuvi's FM transmitter? I did this on
a device for the same purpose and it solved the problem. Does anyone
know of a resource that would allow one to figure out how this can be
done? Warranty and such concerns are besides the question.

Here is how I modified the other unit:
http://www.wolfswords.com/motorhome/mp3_player/index.html

Steve
www.wolfswords.com under the motorhome link

SamSez wrote:

Most likely the static is present because the frequency you have chosen to
transmit on is in use by a station in which you are on the fringe of its
effective broadcast area. This can vary from atmospheric conditions from
day to day, so it's possible that the day you first chose the frequency, the
signal from the interfering station was a little weaker than the day you
started noticing the static.

FM receivers will demodulate the strongest signal on the carrier frequency
your receiver is tuned to (called the "capture effect"). This can be seen
when you pull up next to a person with an FM transmitter in their car using
the same frequency as you if their signal is a little stronger or their
antenna is a bit closer to your car antenna. It goes away as soon as you
drive away. What may be happening is that the signal from the interfering
broadcast station is just strong enough for your receiver to capture such
that it cuts in and out intermittently, resulting in static. Your car radio
may normally squelch these weak signals, so when you are tuning around
trying to find an empty channel, a weak channel will appear to be empty when
it's not completely empty.

The solution? Keep looking for a different frequency. Depending on your
daily travel route, you may actually enter or leave areas that have varying
coverage from that distant interfering station, which means that you either
need to change frequencies when that occurs, or find one that is empty for
your whole trip. In urban areas, that could be challenging. A filter would
not solve this problem.

- Doug

Exactly -- and if Garmin's transmitter was half as strong as the majority
of the $15-$25 FM modulator add-ons sold for mp3 players, there wouldn't be
so many complaints about how bad it is. Let's stop making excuses for bad
hardware...