Balanced Input Sensitivity Measurement Using Unbalanced Signal Generators
Abstract
The problem of measuring the sensitivity of balanced input radio receiving systems with an unbalanced (grounded) standard signal generator is considered for the frequency range 1.5-30 megacycles. Particular emphasis is placed on the sensitivity measurement of direction finder systems employing goniometers with center tapped stators grounded through resistors, often difficult to remove. Three different approaches are discussed: (1) the employment of resistive networks for maintaining a balance, (2) the employment of unbalanced to balanced transformers and (3) the removal of the center tap and measurement as an unbalanced system. Results indicate that all three methods can be made to yield results in agreement within the limits of experimental accuracy. Two shielded balanced-to-unbalanced transformers were built with balance ratios of better than 50 db and coefficients of coupling of 0.93 and 0.91 for the low and high frequencies respectively.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 21, 1945
- Accession Number
- AD1193976
Entities
People
- S. F. George
Organizations
- United States Naval Research Laboratory