The external GPS antenna connects directly to the Juno T41 handheld computer via the MCX port.
(Scroll down for full description)
When your Trimble Juno T41 handheld computer is inside your vehicle, it is common for the GPS signal strength to be reduced by the vehicle itself. To counteract this effect, we recommend the external GPS antenna, which connects directly to the Juno T41 handheld computer via the MCX port.
The external GPS antenna should be mounted to the top of the vehicle, where it has an unobstructed view of the sky. A properly installed antenna enables the Juno T41 handheld computer GPS receiver to calculate your location more precisely, because more satellite signals will be received, especially those that are high in sky and otherwise blocked by the vehicle roof.
Once you disconnect the external GPS antenna, the Juno T41 handheld computer will revert to its internal GPS antenna.