Abstract:
A 25 cm. signal generator is described together with equipment and methods for its calibration.
The signal generator consists of a GL446 lighthouse triode oscillator in a folded coaxial line circuit, thermistor bridge power level monitor, and a cutoff waveguide piston attenuator. Provision has been made for cw. or pulse operation.
The attenuator was calibrated by a method due to Gainsborough and its attenuation constant found to be near the calculated value. The output impedance of the attenuator was found to be reactive and further work is necessary to obtain a resistive output impedance. Preliminary work to determine the available power output by an indirect method developed by Moxon has been undertaken. Some of the necessary equipment has been built and is described along with an outline of the intended method.
