Precise Frequency Calibration Using Television Video Carriers
Abstract
The availability of inexpensive and quick precise frequency calibration methods is limited. VLF and GPS do offer precise calibration. However, antenna placement, cost of equipment, and calibration time place many restrictions on the user. The USNO maintained line-10 television Time of Coincidence (TOC) of station WTTG, channel 5, Washington, DC requires a frequency stable video carrier: This video carrier, 77.24 MHz, is controlled by the same cesium beam standard controlling the TOC of line-10. Excellent frequency comparisons against this video carrier have been accomplished at 95 miles (153 km). With stable propagation and a three foot wire antenna, a part in 10(9) can be determined in a few minutes. Inexpensive field equipment with a synthesized 1 kHz offset from the video carrier offers parts in 10(11) calibrations in a few minutes using an oscilloscope as a phase comparator.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1990
- Accession Number
- ADA520869
Entities
People
- Edward E. Burkhardt