User's Manual

with co-channel users. Pacific Crest recommends using the low RF power setting for
construction site and other line-of-site surveys with baselines less than two miles (depending on
terrain).
Warning: If you are in conflict with a co-channel user, select another frequency to
avoid formal FCC actions. In most cases you are required to vacate a frequency
upon complaint by a shared channel voice user.
Most survey operations are itinerant in that the system is moved on a frequent basis. For fixed
system installations, you should not use frequencies set aside for itinerant operations, but
should coordinate a frequency based on the fixed area operation.
Regulations differ from country to country, so please be aware of the local regulations prior to
using radio equipment.
Automatic Station Identification
For operation in the United States, the FCC requires that radio transmitters used for GPS RTK
applications periodically broadcast a station identifier. The station identifier is the call sign
assigned to you on the station license.
The ADL Vantage supports the broadcast of station identification in a manner that meets the
requirements of the FCC. Upon receipt of equipment, program your FCC call sign into the
configuration of your ADL Vantage using ADLCONF software. This is only required for
transmitters.
Warning: Failure to transmit your station identification is in violation of FCC
regulations. Use ADLCONF software to enter your FCC call sign.
Carrier Sense Multiple Access (CSMA)
CSMA is a technology implemented in ADL Vantage base radios to meet the United States
Federal Communication Commission (FCC) transmitter requirements. It is illegal to transmit on
any UHF radio within the United States without CSMA enabled. CSMA holds off the radio
transmission if the frequency is currently being used by a co-channel user. On occasion, you
may note that the radio broadcasts stop for short periods of time. Most often, this is a case of
co-channel interference and the ADL Vantage base radio is holding off broadcasts due to the
FCC mandated CSMA.
GPS RTK equipment is designed to function with intermittent gaps in the data. Heavy co-
channel use may limit the ability of the ADL Vantage base radio to transmit the required
information. In areas of heavy co-channel usage, try changing channels to a less used
frequency.