The following charts compare various type of coaxial cable used in VHF and UHF data radio systems.  All coax cable has a certain amount of signal loss.  When an antenna is connected to a radio modem using any type of coax cable, the transmit signal is attenuated as it passes through the cable, so the [...]

Obtaining an FCC license to use a narrow-band radio channel is not difficult at all.  In fact, the FCC has listed over 300 ,000 license holders in the Land Mobile Radio service alone. Raveon’s M7 radio modem operate on radio frequencies that are regulated by the Federal Communications Commission (FCC).  In order to transmit on [...]

TDMA, or Time-Division-Multiple-Access is a very effective way of allowing a lot of radios to share one radio channel.  Used extensively in GSM cellular and APCO public-safety systems, TDMA excels at allowing quick and reliable access to radio channels.  Raveon’s M7 series of GPS tracking radios use TDMA to send GPS position information, status, and [...]

Raveon Technologies data radio modems can have either wide band IF filters, which are used on 25kHz or 30kHz spaced channels, or narrow-band IF filters, which are used on 12.5kHz spaced channels.  As the picture above illustrates, it is possible to have twice the number of radio channels, when everyone uses 12.5kHz narrow band radios.  [...]

Wireless SCADA In a traditional wired SCADA system, a device is monitored by some type of computer or other human-to-machine interface.  The user may have something as simple as an LED indicator, or as complex as a computer server for the operator.  The human interface communicates to another electronic device that is remotely located at [...]