General

The measuring system must provide a means for applying bias to the transistor under test. The bias system must be such as not to influence the accuracy of the measurements, The signal applied by the measuring system to the transistor must be sufficiently small to satisfy the "small-signal conditions" defined in 1.2. In addition, any spurious signals which might appear at the transistor terminals, and in particular, the local oscillator feedthrough when a superheterodyne receiver is used, must be kept at least 20 dB* below the specified small-signal conditions.

Ideally, the measurement of the short-circuit forward current transfer ratio would require a perfect short circuit at the output and the capability of sensing both input and output currents simultaneously. As an alternative, an ideal current source of known magnitude and phase can replace the sensing of the input current.

*All asterisks in this document refer to the following footnote:

The numerical values quoted have been agreed upon by the JS-9 JEDEC committee as those representing a practical compromise between the usual requirements of circuit design applications of current gain parameters and tbc measurement technology at the time of writing this document.