Garmin's NavTalk Cell Phone and Road Map GPS Product Review
By Joe Mehaffey and Jack Yeazel
Revision 2 November 2 1999
Now we're TALKING! You want a GPS with built
in base maps? How about with uploadable ROAD, Topographical and World
Map options? Need a cellular telephone? Does your spouse want
to know where you are when you are "out and about"? Garmin provides
ALL of these capabilities in one compact GPS/Cellphone unit called the
NavTalk. See Photo (HERE).
This AMPS (analog) cellphone and GPS combination is a first of its kind.
The uploadable maps from the MapSource Roads and Recreation, Topographical
and World Map CDROMs provide local map details uploadable to the GPS.
In addition, NavTalk has an enhanced base map with a surprising map
detail of the national and state highway systems and other large roads
and highways. This review will focus on the DIFFERENCES between the
NavTalk and the Garmin G-III PLUS along with an overview of NavTalk's cellphone
features. Basically, the NavTalk is a Garmin G-III PLUS GPS
receiver with an integrated AMPS cellular telephone in a single compact
package. Note: For details of the GPS performance, see
the G-III+ Product Review (HERE).
GPS/CellPhone system in Brief:
NavTalk provides almost all of the G-III PLUS capabilities but with
some minor variations (See NavTalk/G-III+ differences below). Features
include: Uploadable maps from optional CDROMs (about 7000 square
miles of urban coverage can be uploaded at one time. This is about
1.4meg bytes of compressed maps. Partial maps from diverse areas
can be uploaded simultaneously), 250 user waypoints, Twenty
reversible routes of 30 waypoints each, city listings with database
information, Interstate highway exits and services information,
Track Log with 1900 log points, TracBack Route Generation,
Ten compressed TrackLogs, and (almost all) features of the G-III
PLUS. Missing are: External antenna connection
for GPS and DGPS capability. NavTalk uses a new proprietary Garmin
interface cable of the "flat face pin" variety and is NOT plug interchangeable
with the G-III cable assembly. Available are: a) PC data cable,
b) Cigar lighter power cable and c) AC Transformer power cable (standard).
Discounted prices are now in the range of $395 for NavTalk. Check
latest prices (HERE).
NavTalk uses a NiMH battery pack which supplies power to both the
GPS and the telephone. Either the GPS or cellphone can be individually
turned OFF to conserve battery power. In tests, the unit would
run for about 16 hours with both the GPS and cellphone ON on a single battery
charge with about 15 minutes of cellphone talk time included. The
AC charger is a small wall cube which charges the unit in about 12 hours.
Click on the G-III Product review link above for detailed feature information
of the G-III PLUS which is essentially the same in the NavTalk GPS receiver
system. NavTalk is rated submersible to 1 meter for 30 minutes
in accord with specification IPX7.
NavTalk Cellular Telephone:
The NavTalk provides a standard AMPS (analog) type cellular telephone
set which is interconnected with the GPS system and which uses the same
display. A GPS/PHONE push button toggles the unit's function between
the two modes. The Cellphone features include: AutoRedial,
Missed Call Indicator, Return Missed Call capability, Missed
call list (including phone numbers), built in phone book with "spell-N-find,
Single digit Speed Dial, Last number redial, signal strength
and battery indicators, Preferred SID list, Several levels
of call restriction, Remote location query capability, Call
timers (for last call and summation) among others.
We had a minor problem getting our Cellular Provider (Cellular One)
to connect our NavTalk to the network. They had never heard of a
NavTalk Phone. After consulting with Garmin and then their reference
manual, they got us working promptly and all is well.
MapSource CDROM Maps for
By using the "US Roads and Recreation" CD by MapSource, the
user GPS storage area allows uploading of from 1 to 25 (max) counties into
the NavTalk. Depending on area, our experiments showed you
could usually upload 6 to 12 counties (the boundaries of which
are indicated as dashed lines on the GPS) depending on the road density
in a particular area. The counties do NOT need to be contiguous.
In the dense Atlanta Metropolitan area, an area of about 7500 square
miles of residential street-level maps can be uploaded into the 1.4 megabyte
G-III+ user memory, about 65% of the capacity of the Lowrance GM-100.
(Note: The Lowrance GM-100 and the G3+ are "head on" competitors
in the marketplace and we will make comparisons from time to time in this
Garmin has introduced a World Map CDROM. As USUAL the out-of-the-USA
road detail is substantially less than the USA road detail in the R&R
system. (Note: This is because of the very high costs of acquiring
accurate and highly detailed road maps outside of the USA. Auslanders
should be working on this with your government representatives!).
However, the detail on the new WORLD MAP CDROM is considerably better
(everywhere we looked) as compared with the GM100 world maps or the older
G-III base maps. The MapSource WORLD MAP also includes "some"
marine navaids whereas the GM100 world maps do not.
See comparisons of the Lowrance GM-100, G-III, and G-III+ US and World
Maps (HERE). Note: As of April 1999, NO software
other than Garmin's MapSource CDROM Maps can be uploaded into the G-III
Look and Feel:
The microphone and receiver (speaker) for cellphone use are on the rear
of the case. Though my hand is continuously on the keys while talking
on the cellphone, I have never accidentally pressed a key which caused
The NavTalk unit is noticeably heavier and more bulky as
compared with The G-12xl (which it resembles). It has a new row of
buttons above the display for power, up/down, and GPS/Phone display
selection. NavTalk is not nearly so light and compact as my Nokia
phone or even the Motorola Flip Phone. It is a bit heavy and bulky
to carry in my shirt pocket as I do with my other handheld cellphones.
However, (in our opinion), the utility of having the cellphone
and GPS in one package are a distinct advantage.
NavTalk's GPS Receiver Sensitivity
Garmin has been slowly improving the receiver sensitivity in their
product line as time has passed. Our earliest G12xl is not nearly
as sensitive as the later model G-12xl. Our G-III PLUS receivers
are more sensitive than those in the G-III. This trend continues
with the NavTalk. The actual sensitivity difference has a) permitted
me to "fairly often" attain lock in my family room which no other unit
tested has done and b) permitted me to maintain GPS lock while
flying on a commercial airliner with the NavTalk on the "food tray" in
front of my window seat. (Note: In this latter case,
the NavTalk would go for maybe 10 minutes with a lock, lose it,
I would put it up to the window for 10 seconds, it would recover
and track along for awhile. NOT perfect, but better performance
than I have had with any other in this situation unless I used an external
antenna. I would not comment on this, but for the
fact that I have noted this performance on three recent commercial
Is this worth buying a NavTalk for instead of some other model?
No.. I don't think I would recommend that. In tests with three
other GPS receivers, the sensitivity difference was noticeable,
but maybe just a db or two. Also, my particular NavTalk test
unit might have higher than normal RF sensitivity or a lower noise figure
All of the late model 12 channel PARALLEL receiver GPS units have
adequate sensitivity for normal use.
MapSource CDROM Electronic
The Garmin MapSource maps are high quality electronic
maps and the system is easy to understand and use. The USA
maps ("Roads and Recreation") are of the same general quality
as Delorme SA5 maps but lack the "tourist interest" and highway detail
provided in SA6. MapSource road accuracy is judged "good"
by Jack and Joe. Other MapSource Maps compatible with NavTalk are
the World Map series and the new TOPO maps for the USA. We think
the topo map detail is quite good and since they come from USGS DRG maps,
they are reasonably accurate even though they have been compressed quite
MapSource was designed expressly to provide uploadable maps to the NavTalk/G-III+
and other Garmin GPS products. As such, it does not have route
computation or tracklog presentation capabilities. It is still necessary
to use an accessory package such as SA6 for automatic route generation,
waypoint upload/download, route and track download. NOTE:
NavTalk *is not* a StreetPilot and it does not have the routing or
"address finding" capability of the StreetPilot. Nor does it have
the capability to 'LOCK' the GPS tracking icon to the roadway as does SP.
So far there is no program like OziExplorer/MapCreate that provides editing
the MapSource files. Waypoint+ and G7TO have the same capabilities
with the NavTalk/G-III+ as with the G-III.
Remote Tracking of
NavTalk offers the capability of having its "current location" tracked
while it is in motion. This can be done by a communication with another
NavTalk unit. Location reporting can be initiated by the unit or
by querying the unit (reference page 59 of User's Manual). To protect
privacy, the unit will not respond to a query unless "Remote Commands"
are enabled. The "Remote Commands" field is password protected,
thus allowing the end user total control over this feature. It is
not currently possible to query the unit without ringing the phone, but
this is a planned product improvement. When available, it will also
be selectable to protect privacy.
WorldWide ($18 per month service includes 25 fixes):
Provides tracking through the use of an Internet service.
All that's needed is an Internet access and an HTML browser including wireless
types. (Access this site and use: ID=demo and PASSWORD=demo
to see how it works.) In normal operation, one would enter an ID
and then a password. When the cellphone is polled, a map of the NavTalk
phone location is transmitted to the user. Several zoom levels are
available to better define the location. Nothing much could be simpler.
But it is expensive.
An example is:
If the cellphone is not on, the last reported location is shown.
The maps appear to be Tiger Maps.
Personal Tracker Software ($195US):
Personal Tracker is designed to work with the Garmin NavTalk GPS.
With the click of a button you can call the person or vehicle with the
NavTalk, and its GPS position will be transmitted to the base station.
The on-screen map will then be centered on the unit's location. Alternatively,
the person with the NavTalk can initiate the call. A single position
can be obtained in about 20 seconds and if desired, the NavTalk can be
continuously tracked, with heading and speed shown on-screen. Personal
Tracker also includes a complete, detailed street map of the United States
for easy location. This will be the cheaper approach in the long
run unless you plan just a few location fix calls a month.
At present there are two commercial modems meeting the requirements
of NavTalk and the Fugawi software which are able to process DTMF (touch-tone)
signaling . Garmin has tested and approved the following two
modems: Diamond Supra Express External and ModemBlaster Flash
56 II External. We will try to obtain one in order report on how this system
DTMF signaling is used. Information is packetized with
error control to insure reliability. Reported
location information includes latitude, longitude, position age, velocity,
heading and HDOP. A "report" takes about 15 seconds after a call
NavTalk uses an internal NiMH storage battery. While tests
are continuing, NavTalk has several times provided more than 16 hours
of combination GPS and cellphone operating time. During this time,
the cellphone was turned on at all times and the GPS was turned on for
about 8 hours of this time. At the end of this interval, the
battery indicator was showing about 1/3 of the battery remaining.
Recharging from "empty" seems to take about 10 hours using the provided
110vac cube tap charger. As our usage and charging experience develops,
we will add further information.
Water Data and Nautical Navigational
NavTalk/G-III PLUS differences:
NavTalk shares the same Water data and NavAid features as
the G-III PLUS. See the G-III PLUS product
review for details.
NavTalk is essentially a G-III PLUS with an AMPS cellphone added.
Features we have found in the NavTalk GPS which are different from the
G-III PLUS are:
1) NavTalk's GPS screen cannot be rotated.
2) NavTalk has no external antenna capability
3) NavTalk can transmit the GPS location via cellphone to another
The Garmin NavTalk GPS/CellPhone system includes battery
charger (Nov 1999 price about $395), data cable (about $30) and the
accessory MapSource Roads and Recreation CDROM Map system (about $100)
constitute a quality and capable road navigation accessory. During
use we had no problems using firmware version 2.05 and we recommend the
NavTalk to those desiring a combination mapping GPS receiver/CellPhone
combination. We LIKE the functionality of having a GPS in our cellphone.
However, the unit is a bit heavier than most current cellphones and
is a bit bigger than comfortable shirt pocket size.
Comments? Questions? Corrections?