Nevada Space Grant
Weight: 115 g, not including cable
Typical current draw: 60 mA @ 5 VDC
This is the GPS we use on our primary and secondary communication payloads. Lots of BalloonSat people use it. Works at both hight altitude and high velocity (during descent). It's fairly lightweight, waterproof and durable.
There are multiple models of the GPS 18
We went for the LVC ($75) model because the bare wire ends
allow you to solder on what you want (i.e. plugs, power adapters). We
power it through the Tinytrak TNC. The weight stated by the
manufacturer is not correct - ours weigh in around 55 grams with short
(4 inch) cable. Compared to the 110 grams for the Garmin 35, the Garmin
18 is the better choice. We also datalog the GPS information using a Sparkfun logomatic.
Has a built in antenna. So you don't need to include a trailing antenna like you do with the GPS 25 models.
Lightweight because it's just the GPS circuit board and an antenna. No LCD or battery.
Takes anywhere from 4.0-5.5 VDC unregulated (TinyTrack can
supply this voltage just fine).
Hard to tell if and when it's working because their is no LCD.