Comparison of AM and Narrow-Band FM UHF Communication Systems. Appendix D - Laboratory Studies and Investigations
Abstract
By means of an investigation under laboratory conditions, engineering data have been obtained on the respective performance of amplitude-modulated and narrow-band frequency-modulated ultra-high-frequency communication systems, the latter system employing a frequency deviation of 7 kilocycles. Models TDZ transmitters and RDZ receivers were used in this undertaking, and operational conditions were simulated in the laboratory by special circuit arrangements. Greater range of communication is provided by the a-m system; however, at shorter ranges, the f-m system yields the greater receiver output signal-to-noise ratio. During co-channel operation, the performance of the a-m system is preferable. Under conditions ordinarily experienced on Naval craft, the f-m system is the more satisfactory during adjacent-channel operation. Neither system is affected by intense radar noise, at the point of reception. High level spark noise, however, impairs the performance of both systems, the f-m system being the more adversely affected Neither system has an outstanding operational advantage over the other.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 18, 1949
- Accession Number
- AD1207273
Entities
People
- H. R. Johannessen
- W. E. Howe
Organizations
- United States Naval Research Laboratory