Nor is there any cable bloating "goiter" for RFI suppression. Notably absent, is any RFI suppression in the form of ferrite beads on the wires exiting the unit. There is also a small 8 pin SO packaged ATMEL serial EEPROM or Flashrom. The "front" side of the board has the digital ASIC and DSP portion of the Zodiac chipset along with 2 ram chips. This diode is there to prevent any damage to the unit from inductive spikes caused by turning the ignition switch off inĪutomotive use, as Rand Mcnally does have a cigarette lighter power adapter cable available as an accessory. The cathode end of the diode is attached to a significant heat sinking copper area on the pc board. A big fat 3 Amp diode sits, reverse biased across the supply input. This is aīit sophisticated for such a low budget receiver. Centrally placed is a 6 terminal ferrite transformer along with a nicely sized schottky diode and a smattering of SOT23 sized transistors, for generating +3.3 Volts and + and - 6 Volts (for the RS232). The switching power supply is an all discrete, no IC, design. Some sort of waveguide witchcraft thingamajig. From an end view, it resembles the back end view of a Looking from directly above it's just a rectangle about. There is an interesting looking device near the RF front end. The back side of the board is where the RF section is and the switching power supply. (Click on the picture to view the original size /resolution) The 3 chip Zodiac chipset is easily seen, with paper stickers identifying ZOD1 Ver: 1.83. This is not something to be expected at this pricepoint. The pc board has components mounted on both sidesĪnd surprisingly, all traces on the board are gold plated. The innards consist of a single pc board and a small "patch" antenna mounted to the underside of the cover. That and the lack of magnetic base leads one to believe that it's not intended for outdoor (out of car) use. Revealed that the unit is not even slightly weather resistant. Judicious application of a drill bit circumvented the rivets. After removing the "decoy" screw, I then discovered that the case was plastic riveted together beneath the 4 rubber feet. Īt the $60 price point, I couldn't resist disassembling the GPS receiver, just to see what was inside. Further investigation reveals that the manufacturer is Talon Technology. The unit is a sticker that says "Made in New Zealand" and FCC and CE logos but no reference numbers needed to track down the original maker. Technically impressive, but of no importance to most users. That is, plus and minus 6 Volts, all from a single +5 Volt supply. One most interesting thing is that it outputs TRUE BIPOLAR RS232 levels. Position pinning defaults to "on" but can be disabled and that state is saved to internal eeprom. It does accept the $PRWIINIT command, which allows initializing the unit with lat/lon and UTC, in order to improve It will not accept RTCM DGPS while in NMEA mode. To all the usual Rockwell proprietary commands, it also responds to $LCGPQ,yyy where yyy is a standard sentence such as GGA, GSV etc, by sending the sentence one time only. It will also accept realtime DGPS corrections via message 1351 while in Rockwell Binary mode. It responds to the Rockwell proprietary $PRWIIPRO command by switching into Rockwell binary mode where raw pseudoranges including carrier phase messages can be enable for logging purposes. $PRWIZCH identifies it as a Rockwell (ehr Connexant) ZodiacĬhipset based GPS receiver. NMEA sentences sent are, $GPGGA, $GPGSA, $GPGSV, $GPRMC and $PRWIZCH. Communication with computer is NMEA 2.0 at 4800 baud via combination power/data cable. On the high side, I went as high as 16 Volts with no problem. I measured the current draw at ~125 ma 5 Volts and varying in inverse proportion to supplied voltage (constant power of ~0.6 watt). It has no batteries of any kind and draws power from a notebook computer via the external "keyboard" port. The GPS receiver is shaped something like a computer mouse, but a little smaller. Notebook computer based moving map combination there is. List price is $99, but they offered a 20% discount for filling out a survey and the unit came with a $20 mail-in rebate. ![]() It was purchased from the Rand Mcnally travel store. I have acquired a Rand Mcnally GPS receiver along with the StreetFinder Deluxe 2000 map program, all for the princely sum of $60. Rand McNally GPS receiver with the StreetFinder Deluxe 2000 - Review by John Galvin.
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