Trimble promotes the use of 900 MHz radios in machine control applications. There are several reasons for this that include; 900 MHz radios do not require FCC licensing, 900 MHz are believed to experience less radio interference, two way communication is allowed with 900 MHz radios meaning that a road DTM could be uploaded to the machine control box by transmitting it from the office.

The negative side of 900 MHz radios is range. They are only capable of transmitting corrections approximately 1 mile. If longer distances are required the user must either move the base radio closer to the equipment or set up repeater stations.

In major metropolitan areas where VRS (virtual reference stations) are utilized there will be a transition to utilizing cell phones to receive corrections. This will allow two way communications and eliminate the range issues.

Martin Instrument is not a Trimble Machine Control distributor however we do work with many Heavy Highway contractors for their GPS rover and robotic requirements. We would be happy to discuss your survey requirements.