Bill,
We use several of this type of antenna...
http://www.trimble.com/timing/bullet-gps-antenna.aspx
It is designed to screw onto a pipe and the interior of the mount has a TNC connector for coax. The antenna is an up looking device with preamp inside. All of the equipment we use these with provide the power for the preamp, either 3.3 or 5 volts. Other than the squirrels chewing through the coax, we have not had any problems in years of service. We use the GPS primarily for the timing reference it provides. That is a steady signal at 10.0000 MHz and time code locked to the Naval Observatory.