Microammeter Indication of High-Frequency Bridge Balance

A visual method of obtaining bridge balance by means of a d-c. microammeter in the plate circuit of an electron tube detector associated with one or more stage of amplification, which gives maximum reading for a state of bridge balance, thereby permitting use of a sensitive meter. A large bridge unbalance reduces the deflection to a low value and as the balance is approached the reading increases. This method overcomes the limitations of the aural method and renders a quantitative determination of the degree of unbalance.