The Ashtech Precision External Antenna Cable from Spectra is a 5 feet long cable that connects the receiver to the external antenna. The small end of the cable with a right-angle plug connects to the receiver while the other larger end screws onto the external antenna. This cable is compatible with a series of GPS device such as the ProMark3, ProMark 100/120 and ProMark 200/220, and can fit into all external antenna from Spectra.
Using an external antenna on data collectors has many advantages. To utilize those advantages, you will need one of these cables.