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).

NavTalk 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 NavTalk: 
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 review.)

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 Plus.

Look and Feel:
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.

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 a problem.

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 flights. )

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 than average.

All of the late model 12 channel PARALLEL receiver GPS units have adequate sensitivity for normal use.

MapSource CDROM Electronic Maps:
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 a bit.

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's Location:

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.

MCT 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.

Fugawi 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 works.

Signaling Features:
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 is established.

Battery System: 
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 Aids:
NavTalk shares the same Water data and NavAid features as the G-III PLUS.  See the G-III PLUS product review for details.

NavTalk/G-III PLUS differences:
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 location.

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?

Contact  Joe Mehaffey                                                         BACK to GPS INFORMATION WEBSITE