gkalbfle
Member
I have seen several posts around the net asking about these two units. I have now tried the both, and have the answer for you. The Uniden GPS utilizes the SiRF Star III e/LP chipset, which has a sensitivity of -159 dB. I have been unable to ascertain the chipset utilized in the Garmin 18x, but their published specifications put the sensitivity at -185 dB. The RF power level received by a GPS antenna on the ground will be between -125dB and -150dB, depending on environmental factors. The Uniden unit gives you -9 dB to account for "environmental factors", while the Garmin gives you -35 dB. In operation, the Uniden unit will acquire a signal in my car on the dashboard, but it will constantly drop the signal while driving, even when there are no external obstructions such as buildings or trees. It really wants to be outside on the roof, which I did not try, because that is not what I expect from a quality GPS. The Garmin 18x on the other hand, acquires and maintains a satellite connection while locked away hidden in the center console of my car. It is a beautiful thing after my experience with the Uniden unit. All you need to connect the Garmin 18x to your scanner's serial cable is this RS-232 DB 9 pin male to male null modem adapter. Set the baud rate on your scanner to 4800 and away you go.
Garyk
Garyk
