Garmin GPS 45/40/38 Frequently Asked Questions ============================================== [start of part 3 of 3] From - Mon Sep 02 07:16:51 1996 Newsgroups: sci.geo.satellite-nav From: klah@eskimo.com (Lane A. Holdcroft) Subject: Garmin GPS 45/40/38 FAQ V1.082 part 3 of 3 [start of part 3 of 3] 6.00 APPLICATION SOFTWARE: --------------------- -What Macintosh software is available for Garmin GPS units? MacAPRS - Amateur Packet Reporting System (shareware): There is also a PC version. This is mapping software written by Radio Amateurs that also supports GPS and live tracking. There are 3 different versions of MacGPS available. Be sure you get the correct one for your use: 1: MacGPS45 by John Waers. Source code and application available free at ftp://ftp.csn.net/Unimac/ [old Mac version] ftp://sundae.triumf.ca/pub/peter/index.html [Mac prog, PC format] This source code is useful to understand the GRMN/GRMN protocol, but this should NOT be used for an actual application or as unquestioned source code for porting to another platform as it has many incorrect- calculation bugs. It was an unfinished work-in-process which John donated to the public domain when he moved on to other things. It doesn't crash, it appears to work, but it gives close but wrong answers in many cases. [Don't use this. Use the later programs.] 2: MacGPS by James Associates. Application available free from ftp://mirror.aol.com/pub/info-mac/sci/ latest file starts with "larrys-mac-gps-"... or any other info-mac mirror site, use the one nearest you. This used John's code as a starting point (with his blessing), but the bugs are fixed, the code is faster, the data transferred is correct, new features have been added, and it works on everything from a Mac Plus to the latest PowerPC (native code). If you want a free program to actually use with your GPS 38/40/45/75/90, this is the one to get. If you are using an earlier version, be sure to upgrade to this latest version. 3: MacGPS Pro by James Associates. Commercial application. This has the complete MacGPS functionality, plus graphical plotting of Waypoints, Routes and Tracks, Waypoint File generation from background maps, and many other features. [It is very inexpensive] If you like MacGPS, you will love MacGPS Pro. It has all of the features of MacGPS, plus many more that our users have been asking for, including: * The current GPS data can be spoken by the Macintosh voice synthesizer for safe use while driving, or for use by the blind. * A zooming, scrolling moving-map type of display showing waypoints and routes, plus tracks, current position, and current velocity vector (speed and direction). Here are the options available on the map menu: Zoom In Zoom Out Fit In Window Keep Current Position Visible Keep Current Position Centered Invert Show Velocity Vector Show Route Distances Wide Track Lines Show Track Speeds Show Track Time Stamps Show Waypoint Names Show Waypoint Comments Show Lat-Lon Grid Lines * A scanned or vector map can be calibrated and used as a background. * Waypoints, Routes, and Track-Log maps for the GPS receiver screen may be generated by simply clicking the mouse on the background map. * Averaging of Real-Time output to obtain more accurate readings. * Almanac Files showing actual GPS satellite orbital parameters. * Set your Macintosh clock from the accurate GPS time. * Display or Upload Real-time (NMEA) files as Track-Log files. * Choosing a National Grid position format chooses the appropriate datum. * Can show Maidenhead grid square location (used by Ham Radio operators). * Works in the background as well as in the foreground. MacGPS Pro sells for [about $30]. People can order it the same way they order GPS hardware from us (email, phone, fax, snail mail, etc.). They normally deliver it by email within 2 hours after they get an order, but they can supply it on disk if someone prefers. It is not shareware, but a regular commercial product. Larry James James Associates lwjames@csn.net -What MS-DOS/Win software is available specifically for Garmin GPS units? There are 2 general ways that software can communicate with the Garmin GPS units: 1) Use Garmin proprietary format that allows you to upload and download waypoints, track info, and routes. 2) Use one of the NMEA 183 software protocols that handles communication between most NMEA 183 instruments such as autopilots, lorans, compasses, etc. Garmin also has some additional unique NMEA 183 style commands which are useful. Here is a list of mostly Garmin specific programs: Garmin's official software kit: Garmin PCX5 software includes cable with DE-9 connector* (price lowered to $99 from $150. Who says Garmin doesn't listen!) MS-DOS based. Reports are that a Windows based version is coming out soon. | Reports are that it is a pretty good program. * I am not sure of the exact wiring of their cable. Are any of the handshake lines connected? Is this the same cable they sell as an option? Here is some more info from a contributor: The Garmin PC Software Kit (PCX5) comes with a dedicated GPS - RS232 connector cable, 1 diskette and a 30 page manual. The PCX5 software can be used to: * download route waypoint, proximity waypoint, almanac and track data * convert route, waypoint and track files to DXF format (CAD) * display digital map in real time * graphically plot data files on screen (with zoom, panning, distance calculation) * print plot files to printer * edit and upload routes, waypoints, proximity waypoints and track data back to GPS * upload almanac data * create satellite visibility charts (for route planning) Garmin recommended system to use the PCX5 software on: * 386 or better * 2MB RAM * EMS (to store plot files) * HD * VGA * math coprocessor * Microsoft compatible mouse I decided to buy the original Garmin software, since I was unaware of other products at that time. But I don't regret my decision, the PCX5 software is easy to install and works smooth. haehlen@ibm.net (Andi Haehlen) ---------------------------------------------------------------------- Fortunately some people have generously written other programs for our benefit: GARDOWN6 and GARDOWN7 by M.J. Montgomery (freeware): Simple but effective MS-DOS programs that download and upload Waypoints, Track data, and Route data. Because of their simplicity, they are easier to troubleshoot any serial/cable interface problems. These programs generally work great with the following caveats: There is an error in the documentation for the syntax of uploading a file in GARDOWN7. There should NOT be a space between the "u" and the filename. The download garmin time "c" option locks up my computers in MS-DOS and causes a General Protection Fault from Windows for both GARDOWN6 and GARDOWN7. I received a response from the author indicating that he does plan to release a new version of the software in a few months but has just been busy with other work. G7TO2x.ZIP (Ron Henderson crh@cv.hp.com) converts GarDown7 download files to Street Atlas 3 format, or vice versa, and converts either format to formats compatible with PROJ.EXE, NAD2NAD.EXE, or UTMS.EXE. This program can also communicate directly with a Garmin receiver using the Garmin protocol, and has been tested on a HP200LX. This is a newer DOS only program that seems to also have all the functionality of GARDOWN. The exact name changes with the version. | EASYNAV COMMUNICATIONS (formerly GARMIN) by Peter Aigner (shareware, $40): | A Windows program written in Visual BASIC to upload and download waypoints, track info, and routes. Since Version A.01.06 it has a several month trial period. You may need to send mail to the author of the program to get a pass code to enable it for the free trial period until you support it. It also downloads some interesting info such as such as the current satellite locations. GARMAP.ZIP provides an interface between Mapinfo Desktop Mapping Software and a Garmin GPS receiver, using the proprietary Garmin/Garmin protocol. Do not forget you have to set your GPS 45/40/38 "I/O SETUP" to "GRMN/GRMN HOST" or the above programs will not work in Garmin mode. GMN_DXF1.ZIP converts the data downloaded by GARDOWN into a .dxf file for import into AutoCad or other drawing programs that read this format. WINGPS by Jos Verbeek (freeware): A Windows program written in Visual BASIC that talks NMEA 0183 but also has some Garmin options. It uses the Garmin data files generated by the utility GARMIN by Peter Aigner. -What MS-DOS/Win software is available that communicates using NMEA 183 format? JNAV82.ZIP by Joel C. Koch (shareware $50): A MS-DOS program that displays and logs NMEA 0183 data. GPSNMEA by Dr.W.Pieper (Public Domain): A MS-DOS program that displays and logs NMEA 0183 data. APRS - Amateur Packet Reporting System (shareware $25+): There is also a DOS version and a Windows version as well as a Macintosh version (MacAPRS). This is mapping software written by Radio Amateurs that also supports GPS and live tracking. You could use almost any terminal program and just log the MMEA 183 data of course. Kermit, Procomm and the MS-Windows Terminal are a few of the most common terminal emulator programs for PC's. GARMIN65.NMEA Prepared by Peter Bennett (bennett@triumf.ca) An annotated listing of NMEA 183 sentences (including Garmin unique sentences) sent by a Garmin GPS 65. The GPS 45/40/38's implementation of NMEA 183 is very similar. Manning Navcomp offers RASTRAC, a WINDOWS/NT/'95/ system that supports popular GPS hardware and moving maps starting at $195. The ADV and MX version supports PCMCIA cards, multimedia advisories and GIF/JPEG/etc. A free version of the software is available for download at http://www.navcomp.com/navcomp/. dnichjr@airmail.net (del nichols) -Other MS-DOS software? Here is a bunch of info about software from one particular company. I have never seen any of their products but I have heard some positive reports and their prices are generally very low. FOR GARMIN MODE ONLY (GPSXFER): GPSXFER is utility which can Download Track logs, Download Waypoints, Upload Waypoints and Combine Files for assembly of map or WayPoint logging. GPSXFER communicates via the serial port to the GPS in use at 9600 bps. The protocol used supports only Garmin GPS's with the following model numbers, GPS-40, GPS-50, GPS-45, GPS-65, GPS-75, GPS-85, GPS-90, GPS-95. GPSXFER allows the GPS to do all the work in the field by collecting track logs and Waypoints, then once back to a computer those records can be retrieved from the GPS by using GPSXFER. The file format that GPSXFER creates can be used with "GPM-PRO" (also available from Cole Enterprises) mapping software to view trips and create maps. GPSXFER runs from DOS. This allows all laptop and Palmtop computers to run it. It supports both Color and Black and White Monitors. The only requirements are DOS 5.0 or later, and 400K of available RAM. This program works great on the HP 200 Palmtop. Price for GPSXFER is $30.00 U.S. GSPDASH and GPSXFER bought together are $50.00. NMEA MODE: The following is a list of S/W products which might be useful for the Garmin GPS's. All of these products work with the NMEA string coming out of the GPS, so this is ideal for the GPS engines. GPSDASH is designed to receive data transmitted by a GPS over a serial port and use it to derive, Speed, Max Speed (Bar graph and numeric), Altitude, Max Altitude,Trip and Total Distance, Latitude and Longitude, Heading (Compass dial and numeric), Number of Satellites used and D.O.P. (Dilution of Precision). Other information displayed in GPSDASH but not derived from the GPS is, Elapsed Time, Current Time, Remaining memory, Log file name , size and divider rate. Distances will be retained from exit of program to re-entry of program so that long time logging can be maintained. GPS's used should transmit NEMA 0183 ver 2.0, although earlier versions can be used but will not contain all of the data. Data rates handled are 4800bps and 9600bps. This program can be run stand alone or as an auxiliary screen from "GPM-PRO" mapping software also available from Cole Enterprises. GPSDASH will automatically initialize the GARMIN GPS-10/20/25/30/31/35/36 series of receivers. GPSDASH runs from DOS. This allows all laptop and Palmtop computers to run it. It supports both Color and Black and White Monitors. The only requirements are DOS 5.0 or later, and 400K of available RAM. This program works great on the HP 200 Palmtop. Price for GPSDASH is $30.00 U.S. GPM-PRO is designed to receive data transmitted by a GPS receiver over a serial port and use it to create real time maps or read in files to view from past trips. The views can be scaled to any size such that overlays can be made for placement on any map. Waypoint entry is extensive which allows the user to create custom overlays for use with the real time mapping or post viewing. During real time mapping other statistics transmitted by the GPS are displayed such as , Speed, Max Speed, Altitude, Max Altitude,Trip and Total Distance, Latitude and Longitude, Heading, Number of Satellites used and D.O.P. (Dilution of Precision). It is a very useful GIS tool. Custom data dictionaries are easily constructed by the user allowing almost unlimited hot key selections. GPS's used should transmit NEMA 0183 ver 2.0, although earlier versions can be used but will not contain all of the data. Data rates handled are 4800bps and 9600bps. GPM-PRO will export two file formats: DXF and TXT (which is +/-Lat,+/-Lon six decimal deg) recognized by Select Street Atlas by ProCD. Conversions to State Plane Coordinates and UTM and on into DXF are available. GPM-PRO is a very advanced and capable tool, with far to many features to list here. For more information call and get the details. GPM-PRO and GPM-SAT will automatically initialize the Garmin GPS-10/20/25/30/31/35/36 series of receivers. GPM-PRO runs from DOS. This allows all laptop and Palmtop computers to run it. It supports both Color and Black and White Monitors. The only requirements are DOS 5.0 or later, and 400K of available RAM. This program works great on the HP 200 Palmtop. GPM-PRO software package includes companion utility programs to manage and convert the data files collected by GPM-PRO. GET-WPTS: Is designed to extract WPT/feature attributes from the *.GPS data files generated by GPM-PRO. These WPT/Feature Attributes can be put into a comma delimited file for analysis or manipulation by a spreadsheet type program or into Location (*.GPM) or Route/Boundary (*.RTE) files used in GPM-PRO as route, boundary, or location information. GET-WPTS will also produce a 7 decimal degree (GEO), State Plane Coordinate (SPC), or Universal Transverse Mercator (UTM) type file and convert each these files to *.DXF format for easy importing to many of the CADD programs available. SORTGPM: Is a designed to to build custom Location (*.GPM) and Route/Boundary (*.RTE) files utilizing existing *.GPM data files or Location and Route data extracted from logging sessions. GPM-PRO is provided with Location files for cities, airports of over 4,000 ft, and FAA VORs (Navigational Sites) in the USA. Price for GPM-PRO and Utilities is $250.00 U.S. GPSDASH and GPSXFER can be purchased for $10.00 each if bought at the same time as GPM-PRO. A complete GPS Tracker kit is available, including a GPS, Palmtop PC, and necessary interfacing cables etc. Call for details and quotes on the Tracker kit and for Custom software/hardware requirements. GPM-SAT is a satellite viewing program that will operate stand alone or in conjunction with GPM-PRO. It shows a sky view of satellites available and over a period of time, history tracks will develop showing the satellite movement. Signal-Noise bars are shown for the individual satellites. When used in conjunction with GPM-PRO, will continue the track log being recorded. Visa/Mastercard Accepted. Or send Check to: Cole Enterprises 614 Cedar Hill RD NE Albuquerque NM 87122-1814 Internet 102115.3550@compuserve.com Sales (505) 856-7402 (505) 856-7446 FAX [Software Quantity Discounts are available for 2 or more copies.] GPM-PRO package includes GPM-SAT $250.00 GPM basic pkg includes GPM-SAT 70.00 GPM-SAT alone single copy 30.00 GPM-SAT if bought with either GPSDASH or GPSXFER 10.00 GPSDASH 30.00 GPSXFER 30.00 GPSDASH and GPSXFER together 50.00 GPSDASH if purchased with GPM basic or GPM-PRO 10.00 GPSXFER if purchased with GPM basic or GPM-PRO 10.00 All orders are plus shipping. -GPS ftp/www sites? Caution, these links are constantly changing! Garmin's software is available though their dealers. Peter Bennett has an excellent ftp site and WWW page which have most of the freeware/shareware programs above as well as info on NMEA 183 and an excellent general GPS FAQ: ftp://sundae.triumf.ca/pub/peter/index.html http:://vancouver-webpages.com/peter/index.html ftp://ftp-i2.informatik.rwth-aachen.de/pub/arnd/GPS/peter/index.html | Good general GPS info: http://www.utexas.edu/depts/grg/gcraft/notes/gps/gps.html Intro to GPS Applications - Archive: http://www.he.net/~jbeadles/gps/index.htm Introduction to GPS Applications Web Page: http://galaxy.einet.net/editors/john-beadles/introgps.htm You can find some basic GPS information links here: http://www.inmet.com/~pwt Tim Hogard has Garmin electrical hardware and Garmin's proprietary protocol information on his Web site: http://www.abnormal.com Larry James has inherited the MacGPS_45 software: http://www.csn.net/~lwjames | Here is a mirror site for MacGPS_45: ftp://ftp.hawaii.edu/mirrors/info-mac/sci/larrys-mac-gps.hqx Comparison chart of most GPS handhelds and their features: http://www.eskimo.com/~archer/gps.html | Larry Berg of Purple Computing trades for his homebrew Garmin connectors: http://home.cdsnet.net/~purple/projects/g45contr/g45_idx.htm | US Coast Guard: http://www.navcen.uscg.mil/ US Geodetic Survey: http://www.usgs.gov/ DeLorme Mapping's home page: http://www.delorme.com/ Precision Mapping home page: http:\\www.justsoftworks.com | Eagle home page: http://www.uni.net/eagle/ | Lowrance home page: http://www.lowrance.com | Trimble home page: http://www.trimble.com | APRS (Automatic Packet Reporting System) has a MS-DOS version and a Windows version as well as a Macintosh version (MacAPRS) that support GPS and mapping. The shareware is available from: ftp to "ftp.tapr.org" cd to "/tapr/SIG/aprssig/files/" | or web address: ftp://ftp.tapr.org/tapr/SIG/aprssig/files/ | US Lat/Lon database by city: http://tiger2.census.gov/places.html GPS World magazine (the printed trade publication for professional GPS users): http://www.gpsworld.com | http://www.advanstar.com/GEO/GPS/ MIT's scatter plots for GPS w/ SA & GLONASS (Russia's version w/o SA): http://satnav.atc.ll.mit.edu West Marine http://www.gsn.com/westmarine | The very latest version of this FAQ is available on my www and ftp sites (however I usually send it to Peter Bennett's site very quickly): http://www.eskimo.com/~klah/index.html (preferred) or ftp://ftp.eskimo.com/u/k/klah/index.html or ftp to "ftp.eskimo.com", cd to "/u/k/klah" -Digital maps with lat/lon? This section is very preliminary and so far only has US maps! DeLorme's Map Expert V2.0 (Windows). Excellent program, but expensive. Lat/Lon at cursor. Selectable Lat/Lon grid overlay. $300 discounted DeLorme's "GPS Link" for Map Expert above Offers real time track data by reading NMEA 183 output. $200 discounted (The previous 2 programs are available in the "GPS MapKit" for about $500) Map'N'Go by DeLorme mapping ($40) A Windows street level mapping program that can talk to GPS's using both NMEA and Garmin's protocol. | DeLorme's Street Atlas USA V3.0 (Windows). DeLorme's Street Atlas USA V3.0 (Macintosh). V3.0 added Lat/Lon support, unlike V2.0. However, the lat/lon at the cursor is not always displayed under all conditions. Not nearly as powerful as DeLorme's Map Expert but has the most important stuff. Generally considered pretty good for the price. It uses the WGS-84 datum. 800-452-5931 $80 list price, sometimes heavily discounted. Precision Mapping V2.0 discounted to about $40. Just Softworks Inc. (708) 257-7616 A little clunky but has many features. Somebody claimed that there is a "lite" version that does NOT support Lat/Lon. The Precision Mapping GPS Edition was just released in July 1996. There is also a Complete GPS Kit for $339. http:\\www.justsoftworks.com Microsoft Automap Streets V4.00 MS-Windows based. Turn on lat/lon by selecting Tools,Track. Lat/Lon is displayed for mouse cursor only. There is an additional software supplement on Microsoft's BBS but it does NOT speak normal NMEA or Garmin protocol and is useless on Garmin units! There is support for some Rockwell, Sony, and Marconi GPS units only! Someone else is working on some interface software. So far it is not good choice for live GPS'ing. | List price recently dropped to $55 7.00 ANTENNAS: --------- -What is the GPS 40/38 internal antenna? It is a "patch" antenna design. The same antenna is also used on the optional remote antennas GA 27 (GPS 40) and GA 26 (GPS 45) except that the remote antennas are amplified. -How is the GPS 45/90/89 antenna internally constructed? Thanks to a friend whose GPS 45 antenna case split open, we were able to examine the antenna construction. It is a quad-helix circular polarized antenna. It basically looks like a double sided flexible circuit board rolled into about a 1/2 inch diameter cylinder. It has 4 spiral elements that look like the stripes on a candy cane. It is definitely a a passive (non-amplified) antenna. However, it does work very well. Several people have reported that when the plastic protective antenna case is removed, it doesn't work as well due to detuning the antenna. Someone has X-rayed their GPS 45 antenna and scanned the image. Look at the files grm45ant.gif and grm45ant.inf on Peter Bennett's ftp/www site as listed elsewhere in the FAQ. -How well does the internal antenna work inside a car? You can use a GPS unit on the dash of your car with the normal antenna but the roof of the cars shields about 1/3 of the satellites. I typically get 4-6 satellites (adequate) on the open road and less when between buildings or trees. Of course it depends on the slope of your windshield and where you place your GPS unit. There are some window tintings (which could also be used in a sunroof) and some electric window defoggers that use a conductive coating between the layers of glass that block the satellite signals. These are unusual but they will shield the signals from the antenna. Of course you can get much better reception with an external antenna on the roof. -What are the remote antenna options? GPS 45/40: There are several basic approaches to external antennas: 1) Obtain an external antenna. If the coax is going to be longer than several meters, then the antenna should be amplified to overcome the signal losses in the coax. The GPS 45 and 40 supply 5 V to the coax connector. 2) Use the existing non-amplified antenna and insert a short piece of coaxial cable between the connectors. With this approach, you only have to pay for a coaxial cable extension and perhaps a gender changer and/or 90 degree elbow. The satellite signals are severely attenuated by coaxial cable at the civilian GPS frequency of about 1.5 GHz. If the original (non-amplified) antenna is used, the cable length should usually be kept less than about 3 meters. Garmin sells a couple of external antennas that work very well. There is a wide range of mounting options including suction cups, magnetic, flange, and trunk lid mounts. See the accessories section of the FAQ for details. Many people have reported that the external antennas work better than the built in antennas when they are walking through trees. This could be because your body is not shielding the signal and most external antennas are amplified. If you are walking, you could mount the external antenna to your hat or to a pipe coming out of a backpack. Garmin sells a non-amplified remote antenna for the GPS 45 for about $40. I have not heard any reports about it yet. It sounds like a good low cost solution for use with your car or when walking as used above. -GPS 45 antenna extension cables? You can buy a SHORT coax extension and mount the antenna on the inside of your windshield or sunroof. Radio Shack sells 6 foot coax RG-58/U extensions with suction cup mounts (RS 20-022) or a window edge mount (RS 20-023) for about $15. You will need a 90 degree elbow (RS 278-116a) for the window edge mount and it can be useful for the suction cup mount too. However there is a risk of antenna theft or possibly the antenna flopping down or falling off. Also, the coax can get pinched in the window or alternatively there will be a noisy air leak. You can also just buy a piece of coax but you will also need a BNC gender changer and a way to mount it. The 6 ft of RG-58/U (a very lossy coax at these frequencies) drops the signal strength a little on the display. Garmin offers a 6 ft antenna extension for the GPS 45 (Garmin 5519). It has a screw/suction cup mount. It costs about $40. -Can I make my own external antenna? Yes. There have been several postings that reference the articles below. A GPS antenna is difficult to design for many reasons: The signal is very weak. The frequency is quite high (1.5 GHz). Antenna tuning is very difficult because of the expensive equipment required. A hemispherical radiation pattern is desired. Right hand circular polarization is desired. In the ham radio magazine "QST" (October 1995) there is a good article on how to simply construct a "patch" style GPS antenna using easy to obtain materials. The file "gpspatch.zip" on Peter's ftp site also has lots of information. It is relatively easy to construct and the materials are inexpensive! You may want to use an easier to solder material than aluminum if you don't have copper foil tape or appropriate solder and a large iron. Some people have found the signals to be weaker but they all have worked. Several people reported that it doesn't work as well for satellites near the horizon. However, it is still the best antenna design I have seen so far for home construction. The "Satellite Experimenter's Handbook" (by Martin R. Davidoff, published by the American Radio Relay League) has a quadrifilar helix antenna. It could be tough for many people to get the very small coaxial hardline that is needed. The dimensions are very also critical. This particular antenna apparently presents a dead short to the +5V supply on the GPS unit's external coax connection if connected normally. Therefore, the antenna likely needs to have a small decoupling capacitor in series with the center wire of the coax to prevent blowing the internal fuse ($150 service charge!). When my antenna is complete I'll post more. If the coax is longer than several meters, you will likely need an amplifier to overcome losses in the feedline. Several people have suggested the Mini Circuits MAR-6 amplifier which looks like an excellent choice because of its low voltage, low current, good gain at 1.5 GHz, and its ease in impedance matching. It also only costs about $2 in quantities. Apparently, Ma/Com also makes a GPS preamplifier IC ($8) which is designed for this application (but much harder to obtain). -What is the loss for different coaxial cables? Based upon information in the spec sheets for coaxial cable, I think RG-6/U (75 ohm) coax is the most attractive from a standpoint of loss at 1.5 GHz and flexibility but it is not 50 ohms. Another poster independently came to the same conclusion. The loss would not be much of an issue if the run was less than several meters. The losses due to a impedance mismatch would likely be less significant than the attenuation of the cable (at least for longer runs). Even Garmin uses RG-59/U coax (75 ohm) on one of their external antennas. loss per 100 feet RG-__/U Z OD(in.) dB (@1GHz) SORTED BY IMPEDANCE & LOSS: 218 50 .880 4.5 219 50 .880 4.5 217 50 .555 6 8 52 .415 8.8 212 50 .336 8.8 213 50 .412 8.8 215 50 .412 8.8 214 50 .432 9 223 50 .216 17 55 53 .206 17 58 50 .200 20 (solid center?) 58A 50 .200 23 (stranded center?) 58C 50 .200 23 174 50 .105 >>20 6A 75 .274 11.2 *best tradeoff between size, loss, & impedance? 59 75 .250 14 62 93 .250 9 71 93 .250 9 63 125 .415 6.5 Here is another chart from another source showing the maximum cable lengths. Note that the cable loss specs are different probably because there are minor variations in the coax type. Max cable length for a non-amplified antenna is about 8-9 feet using RG59 and 6 feet using RG58. Other cable types will differ. Here's a cable loss chart for a Garmin amplified antenna: CABLE TYPE MAXIMUM LENGTH RATING AT 1GHz RG211A/228A 217 ft 4.5 db/100' RG217/224/293/14 126 3.8 RG8/215/216 87 9 RG6/142 71 11 RG59 64 11.5 RG58 40 20 RG88 26 30 -What is the GPS 40 antenna connector? The Garmin GPS 40's antenna connector is called an MCX connector. One primary manufacturer of these connectors is: Huber & Suhner Inc. One Allen Martin Drive P.O. Box 400 Essex, VT 05451 One of the representatives (who sent me their 1" catalog of RF connectors) is: C.W. Swift & Associates, Inc. 15216 Burbank Blvd, Suite 300 Van Nuys, CA 91411 (818) 989-1133 (818) 989-4784 (Fax) (800) "MICROWAVE" -> 642-7692 Keith Huie I talked to C.W. Swift & Associates today and the Garmin GPS 40 antenna connector (MCX) has the part number 16MCX-50-2-5C/133 (this is the right-angle version [for RG-316 cable]). It costs $5.01 qty. 1 and they have a minimum order of $50. They will take orders less than $50 but will charge $5 for handling. Tim Tsai They also have cable assemblies with an MCX on one end and either F, BNC, or TNC on the other. Cable can be either RG-179 (75 ohm) or RG-316 (50 ohm). These cables are small diameter and not real low loss. I would suggest getting a 1 ft cable assy and then adding on a length of a much lower loss cable such as Times Microwave LM-240 or even LM-400 to go the rest of the distance. Jerry Lucha 8.00 MISCELLANEOUS: -------------- -GPS mounting options? Garmin sells a very nice swivel clamp bracket for $45 (list). It used to be included w/ the GPS unit but they lowered the price and removed it and a cable. There are other companies that make GPS mounts, ham radio mounts, and cellular phone mounts for less money but they are not as nice as Garmin's. Velcro (tm) adhesive strips (the generic name is "hook and loop" fasteners) work out well for use in many locations and are very inexpensive and are available at Radio Shack and some sewing supply stores. -Waterproofness: The GPS 45/40 is called "waterproof". It sounds like most units are, but many are not. More than a few people have reported leaks resulting in fogging in which the unit was submerged. This was often due to use in a kayak. | I got the same story from Garmin Technical Support as several other people. "We guarantee it to be waterproof [for one year] but don't recommend submerging it." | I would NOT submerge the units although they should be able to take splashed water. It was recently suggested to me by a dealer that when the units are held horizontal and splashed water collects on the face, it can result in leaks around the keypad. He suggests mounting the unit at an angle to shed water instead of mounting it horizontally. Garmin has been pretty good about supporting their one year warranty. After that, you are on your own! It is filled with nitrogen to prevent the screen from fogging due to condensation. The battery compartment is not waterproof (to allow venting for the batteries) and it would seem to be a good idea to dry out the compartment and batteries after exposure to water. If you don't want to take any chances and expect to submerge it, I would buy a marine radio waterproof plastic bag at well stocked marine supply stores. They usually have a huge Zip-Lock (tm) type seal which keeps the water out pretty well. You could also use an inexpensive "ziploc freezer bag" from your local grocery store. They are not as thick as the $20 bags but thicker than the sandwich bags. If you want to feel better taking your GPS near water, several companies make waterproof bags. One of the better ones is manufactured by Aquaman, aptly called the Aqua Pac. Call AccessorEase at 800-413-9009, they go for about $20. They make two sizes. One fits the GPS 95 and the Lowrance AccuNav and other big GPS receivers, they stock it as the BD43. For the smaller ones like the 45 etc., the BD 45 works like a champ. I don't know about everyone else, but I think it's pretty cheap insurance. tomzman@aol.com (TomZMan) If you were to open the case, you would break the ultrasonically welded seal and it would leak water. It is NOT resealable. It has been suggested that you should grease the GPS 45 antenna connector before exposing it to salt water to help prevent corrosion. I have heard reports of significant corrosion after the BNC connector was splashed with salt water. The GPS 45 antenna case seal between the two halves can break. | Some people have suggested that that the GPS 40 is a little more waterproof and corrosion proof because it doesn't have a BNC connector. This would be especially true for the GPS 38 since it does not have any external antenna connector. The Magellan DLX-5 and DLX-10 are very waterproof but are very large. Unfortunately their software is not nearly as nice as Garmin's. | -Cases? The case that now comes with the unit is strictly a carrying case and the unit is not operable with it because it does not have a clear window. West Marine has a blue (formerly yellow) neoprene rubber "floating" padded carrying case with a somewhat clear plastic window (for use of the buttons and display) and its name printed on it for $12. The West Marine part# is 253791. It does not keep water away from the GPS unit. It looks like it was designed for the GPS 40. The GPS 45 is a little tight around the antenna connector where the antenna hangs off so you have to careful how you swing the antenna. It is a good investment in my opinion. However, the display is not as easy to read through the flexible plastic window. -Garmin 45/40/38 wish list? Here is a list of suggestions for Garmin that people have suggested and which I think would have broad appeal in my order of priority: Remove the 90 knot speed limit. Add distance traveled function (not straight line distance between 2 points). Perhaps select end points by waypoints or on track log. This data is already in the track log. [this was included in the new GPS 38 and GPS 45XL] Save altitude to waypoints and track log. | Add a display mode in which the velocity and heading in degrees are in HUGE numbers for easier viewing from a distance. Add selectable stationary position averaging feature for more accuracy (such as offered by Trimble's "Acu-Lock"). | Add selectable longer averaging time for velocity. Currently it seems about 5 seconds? Velocity is currently of little value for sailboats due to SA. Allow editing for renaming of existing waypoints and creation of new waypoints. Usually the new name is similar to an existing name and it is frustrating to have to start from scratch instead of starting with the existing names. Use flash ROM so the unit's software could be easily upgraded through the serial port. Unfortunately it would be more expensive. Add "over and up" feature to automatically handle map interpolation (such as offered by Trimble). Adjustable proximity alarms would be handy. Remove the limitation of only showing the 9 closest waypoints on the track log map. This is very annoying and seems totally unnecessary! It would also be nice to have more than one page of "closest waypoints". Remove the limitation of only showing waypoints within a certain distance of the current location on the track log map. -Can I use my GPS unit in a plane? You must first have the pilot's permission. It is possible that the GPS unit could interfere with the navigation/communication systems. This does not usually happen, but it could. This is true for many electronics, especially if they involve a radio receiver (which is part of a GPS unit). It is against most airline policies to allow the use of most personal electronic devices during takeoff and landing (and some extend beyond that). I have not seen the specific FAA rules so am not sure if they have additional limitations. Of course, the GPS 45/40/38 will not work above 90 knots anyway so it would only be useful on slow planes or gliders. -Performance in trees? GPS reception is always difficult in thick trees for all GPS receivers. The attenuation depends on the density of the canopy, and how much moisture is in and on the leaves. If the canopy is too dense, you may have to find a clearing to get a fix. I have observed that the Garmin sequencing receivers perform well among trees that grow in very dry climates but perform poorly among trees that grow in wet climates. Several people have reported that the external antennas work better than the built in antennas when they are walking through trees. This probably is because your body is not shielding the signal and most external antennas are amplified. If you are walking, you could mount the external antenna to your hat or to a pipe coming out of a backpack. The GPS 45/40/38 do not perform quite as well as a few other units when surrounded by trees. This is because the GPS 45/40/38 is a single channel sequencing receiver that sequences between 8 satellites instead of having more continuous channels like some other units. Continuous receivers are able to track more marginal signals at once. However, they cost more, are larger, and do not have the battery life of a sequencing receiver such as the GPS 45/40/38. Garmin is about to start shipping the GPSMAP 175 which is a new 12 channel handheld instrument that should be excellent for use under heavy tree cover. It will be similar to the GPS 195 aviation unit which is internally somewhat similar to the GPS 130. | The portable Trimble products (3 parallel channels) and the Eagle Accunav Sport (5 parallel channels) are the most often mentioned examples of portable GPS units with parallel receivers. Trimble products are considered to be of very high quality but are more expensive than the Garmin 45/40/38 and not as feature rich (ie. no graphics). | The Eagle Accunav Sport is considered by many in the newsgroup the other good buy in inexpensive GPS units. It is available for as low as $350 discounted. It uses Rockwell's newer Micro Tracker/LP GPS engine. There is a review of the Eagle Accunav Sport on Peter Bennett's ftp/www site listed elsewhere in the FAQ. The Lowrance Global Nav Sport is very similar but somewhat more expensive. | The Eagle Accunav Sport and Lowrance Global Nav Sport have some advantages over the Garmin 45/40/38: It has a parallel receiver. It does not have the 90 knot speed limit of the Garmin marine units. It has a larger graphical display. It is not expensive for a parallel receiver at about $350 US discounted. However, there are some disadvantages to the Eagle/Lowrance "Nav Sport" The $350 - $400 "Nav" only has the datum WGS84. * | The $350 - $400 "Nav" does not have UTM coordinates. * | It is somewhat larger than the GPS 45/40/38. It has a very short battery life using its internal batteries (but would work fine with an external battery pack). You can NOT download the track log. | * These serious deficiencies are addressed in the Eagle AccuMAP Sport and the Lowrance Global MAP Sport (which cost over $600!). | -Internal electrical hardware? Tom Miller and Tim Hogard bravely took apart their GPS 45/40 units and they described the circuit board. Check out Tim Hogard's home page as listed in the ftp/www sites section elsewhere in the FAQ for more information. Here are some of the most interesting identified parts: Manuf. Part No # pins Function INTEL TS80L188EB13 80 CMOS 80188EB cpu ATMEL AT27LV020 32 3.3V 256k x 8 (2Mbit) EPROM DALLAS DS1202 8 serial time IC & small NVRAM MITS M5M5256CVP 28 32K x 8 SRAM PHILIPS SA626DK 20 FM IF amp,det,limtr,mixer,osc GARMIN ? custom IC #1 GARMIN ? custom IC #2? The Intel 80L188EB microcontroller is a derivative of the Intel 8088 microprocessor used in the original IBM-PC. Contrary to some initial reports, the firmware is not in flash memory. (Flash memory would be of interest because flash is re-programmable without removing the part from the board). The EPROM (which contains the firmware) is a "One Time Programmable" (really an EPROM without a window) surface mount unsocketed part. It must be removed for a firmware upgrade. The fact that the firmware is in EPROM, explains why it costs so much for a firmware upgrade (not that an upgrade is necessary). It would require breaking open the case, desoldering the surface mount EPROM, resoldering the new one, testing the unit, replacing the case, ultrasonically welding the case, filling the case with nitrogen and resealing it. -Why is the firmware not in a socket? There are several reasons why manufacturers generally are reluctant to use sockets: 1) Reliability. There is a much less reliable connection with sockets. 2) Cost. Sockets (other than for DIP IC's) are usually expensive. 3) Clearance. Sockets require more space above the circuit board. The advantages are that sockets make firmware upgrades and troubleshooting easier. -Can I receive GPS signals through my house? Sometimes you can receive a signal indoors. A metal roof, metal siding, or metal foil vapor barrier would block most of the signal. Of course, even if there isn't any metal blocking your signal, other construction materials such as wood or roofing materials will attenuate the signal to a lesser degree and entirely block it if there is enough between your antenna and the satellites. -For how long will a particular track interval interval collect data? I just got my new Garmin 45 last Friday and played with it over the weekend at my deer lease. I kept wondering where I should set the logging to so I put together the following table. It may help others. Garmin 40/45/38 Capabilities based on 768 Points Sample Rate Sec Min Hr Day 1 per sec 768 12.8 1 per 5 sec 3840 64 1.1 1 per 10 sec 7680 128 2.1 1 per 15 sec 11520 192 3.2 1 per 20 sec 15360 256 4.3 1 per 30 sec 23040 384 6.4 1 per 45 sec 34560 576 9.6 1 per min 46080 768 12.8 1 per 1.5 mn 69120 1152 19.2 1 per 2 min 92160 1536 25.6 1.1 1 per 2.5 min 115200 1920 32.0 1.3 1 per 3 min 138240 2304 38.4 1.6 1 per 5 min 230400 3840 64.0 2.7 1 per 10 min 460800 7680 128.0 5.3 1 per 15 min 691200 11520 192.0 8.0 1 per 20 min 921600 15360 256.0 10.7 1 per 30 min 1382400 23040 384.0 16.0 1 per hour 2764800 46080 768.0 32.0 MacBob1240@aol.com (Robert C. White) 9.00 GARMIN PRODUCTS: ---------------- -Garmin GPS models? WARNING: There could be some mistakes! List prices change often. Discounted prices can be variable and they only apply to some dealers in the US. OUTDOOR/MARINE PRODUCTS INTRO $US $US MODEL USE YEAR SPEED LIMIT DISC LIST ----- --- ---- ----------- ----- ----- GPS 38 marine, hiking handheld 1996 90 knots $195 $300 GPS 40 marine, hiking handheld 1994 90 knots $270 $425 GPS 45 marine, hiking handheld 1994 90 knots $280? $495 GPS 45XL (available late July 1996) 1996 90 knots $300 $495 GPS 50 marine, old, replaced by GPS 75 <1992 90 knots? NA NA GPS 65 marine mount, works like GPS 75 1992 90 knots $400 $665 GPS 75 marine, hiking handheld 1992? 90 knots $380 $825 GPS 80 military GPS 40 w/ 5-40V input 1995 ? $900 GPS 120 marine mount 45 w/ big display 1995 90 knots $380 $750? GPSMAP 130 marine mount 12 ch w/ map 1996 90 knots $700 $1090 GPSMAP 135 12 ch w/ sonar and map 1996 90? GPSMAP 175 marine/hiking 12 ch handheld 1996 90 knots $650 $1082 GPS100MRN handheld/portable 90 $1850 GBR21 DGPS beacon receiver n/a $500 $799 MAP 205 chartplotter, no GPS n/a $770 $1249 GPSMAP 210 chartplotter, B&W 90 $1000 $1655 GPSMAP 220 chartplotter, color 90 $1650 $2730 Notice that all of Garmin's marine units have an artificially low speed limit. This speed limit did not start with the Garmin 45 as some have suggested. AVIATION PRODUCTS $US MODEL USE SPEED LIMIT LIST GPS 55 aviation (discontinued?) 1992 695?knots? GPS 89 aviation, cheaper GPS 90 1996 999 knots $450 $599? | GPS 90 aviation, similar to GPS 45 1995 999 knots $650 $799? GPS 95 aviation (discontinued?) ? ~999 knots? | GPS 95XL aviation (aero ver of GPS 75) ? ~999 knots? $1495 GPS 100 STD handheld/portable 999 $1795 GPS 100 PRT handheld/portable w/ dbase 999 $2095 GPS 100 AVD handheld/portable w/ mnt rack 999 $2495 GPS 150 panel mount, VFR 999 $2995 GPS 155 panel mount, IFR, n-p approach 999 $4995 GPS 165 DZUS rail mount version of GPS 155 999 $6495 GPS 190 GPS w/ VHF transceiver 1996 ? ? GPS 195 aviation version of GPS 130 1996 ? ? GNC 250 panel mount GPS/COMM 999 $3250 OEM/BOARDS/SENSORS [These units do not have displays. They are for remote use only.] $US MODEL USE SPEED LIMIT LIST GPS 20 MultiTrac8 sensor board (eval kit), 999 kts $499 $150 in quantity w/o antenna, $240 in quantity w/antenna GPS 25 PhaseTrac12 (eval kit), 12 channel sensor board (eval kit), 999 kts $599 $225 in quantity w/o antenna, $315 in quantity w/antenna [this has a parallel receiver] GPS 30 Integrated antenna/sensor board 999 $340 $499 (eval kit), $240 in quantity GPS 31 Marine mount version of GPS 30 999 $355 GPS 35 12 channel version of GPS 30 999 $599 (eval kit), $315 in quantity GIS/SURVEY PRODUCTS $US MODEL USE SPEED LIMIT LIST GPS SRVY II portable w/ datalogging capabl. 999 $2995 -Garmin accessories? Here is a list of most Garmin accessories: List prices as of Feb 1995: [THESE PRICES ARE OLD AND SOME OPTIONS HAVE BEEN DISCONTINUED] GPS40 part number Item description list price GA27 Low Profile remote ant w/8ft [RG-174] $ 160.00 cable MCX connector & magnetic&suction mount 010-10061-00 Trunk lip mount GA 26/27 18.95 010-10062-00 Flange mount GA 26/27 18.95 011-00152-00 Suction cup mount GA 26/27 18.95 011-00153-00 Magnetic antenna mount GA 26/27 25.00 320-00048-00 8 ft extension cable GA 27 40.00 4015 GPS 40 carry case 35.00 4040 GPS 40/45 Cross load cable(unit to unit) 50.00 4041 GPS 40/45 PC Interface cable 30.00 4042 GPS40 data cable 25.00 4050 GPS 40 cigarette lighter adapter 50.00 4514 GPS 40/45 PC Software and cable kit 150.00 4518 GPS 40/45 mounting bracket 45.00 GPS 45 GA 26 low profile remote ant w/magnetic&suction cup with 8 ft cable BNC connector 160.00 320-0049-00 8 ft extension cable for GA 26 40.00 GA 28 low profile remote marine ant w/30 ft cable and BNC connector 160.00 010-10067-00 GA 28 flange mount kit 22.00 1011 Marine/RV remote ant w/30 ft cable BNC 160.00 1013 30 ft low-loss ant ext cable w/connectors 115.00 1028 Magnetic mount ant with 10 ft cable 160.00 4522 GPS 45 handheld/portable ant 100.00 GPS 45-000 GPS 45 w/ Portable antenna 495.00 | 5519 Remote antenna mount: suction cup/screw mount w/ 6ft cable BNC 40.00 4040 GPS 40/45 Crossload cable (unit to unit) 50.00 4041 GPS 40/45 PC interface cable 30.00 4514 GPS 40/45 PCX5 Software and cable kit 150.00 4515 GPS 45 carrying case 35.00 4518 GPS 45 mounting bracket 45.00 4520 GPS 45 power/data cable 30.00 4550 GPS 45 cigarette lighter adapter 25.00 Disclaimer: These prices may not be current list check around and see if deals exist Sid wa2fxb@ix.netcom.com ( a buyer not a dealer, stockholder and have no vested interest in Garmin) -Where can I purchase a unit? Garmin should be able to locate a local dealer. New address and phone numbers: Garmin International 1200 East 151 St. Olathe, Kansas 66062 Toll free: (800) 800-1020 Non Toll free: (913) 397-8200 Existing Fax: (913) 599-2103 New Fax: (913) 397-8282 Many marine supply stores carry the GPS 45, 40, and 38. Here are some most often mentioned sources for Garmin products: Bass Pro Shops 800-227-7776 or 417-863-2499 Boater's World 800-826-2628 or 206-575-1920? Cabellas 800-237-4444 or 308-234-5555 or 308-235-5555? | E&B Marine 800-533-5007 or 908-819-7400 West Marine 800-538-0775 or 408-728-2700 Larry James of James Associates 303-530-9014 new E-mail address: lwjames@csn.net [As well as being a Garmin dealer, Larry is very knowledgeable about Garmin units and often provides information to the GPS newsgroup.] ---------------------------------------------------------------------- Repeating: I am not affiliated with Garmin or any of their retailers. This document is not in any way endorsed by Garmin International. I am only a satisfied customer. Lane A. Holdcroft klah@eskimo.com KE7UT [end of part 3 of 3] ------------------------------------