Mission Statement:
"To provide equipment, expertise, support, training, and services to the faculty, students, and staff in their pursuit of education through traditional and alternative methods of delivery."


Butte College Television (BCTV)

GPS Control

Although this picture may not look like much, this rack contains the heart of the system required to keep BCTV on the air. The technology behind transmitter phase/frequency lock is nothing new, and is used all over the country at any number of other ITFS stations. Butte College Television is the only regional station to our knowledge that uses this technology to insure an interference free signal to our viewers.

GPS unitsThe actual GPS receiver mounts in the same rack as our transmitters. The unit is capable of some really interesting things, although we only use it for its rock stable 10 MHz reference frequency output. Besides providing a phase stable reference for our transmitters, it can also tell a person using the front panel display exactly where in the world they are accurate to within 40 feet. It used to be worse than that, but the Department of Defense stopped introducing a continually variable percentage of error within the civilian GPS system back in the mid-90’s. Before then, civilian users could only get accuracies to within a hundred yards or so.

The units shown in this picture are: (from bottom to top)

  • TrueTime XL-AK satellite time and frequency receiver. This is the basis for the system, and provides both time and frequency outputs accurate to X10 (- 12) precision. The front panel LCD readout will display over 30 parameters of its operation, as controlled by the buttons on the right. You may also notice a US Robotics external modem sitting just on top of the unit. The XL-AK is fully remote controlled by telephone.
  • COMWAVE 10 MHz / IF frequency reference shelf, to distribute the phase stable signals to all transmitters. This reference shelf takes both the 10 MHz signal and a locally generated 45.75 MHz I.F. signal and evenly splits it to all the television modulators and RF amplifiers.
  • COMWAVE TVM-102 television modulator for channel A-2 that just happened to be in this picture. The entire room is really crowded, so it is next to impossible to snap pictures from the actual front of the rack!