Portable operation from a tripod lent itself to a design that had controls on all sides if that made operation easier. This breadboard style is typified by the equipment built by the late G2DSP, one of the early pioneers of microwave operation. It is a wide-band FM system with both voice and tone modulation.
This plan view of the tranceiver shows how the design is built around a directional coupler. The Gunn oscillator feeds the signal straight along waveguide to the horn antenna. In the mid section of the waveguide is the directional coupler. The left arm is terminated with a dummy load. The right arm passes to the wavemeter and then to the detector diode.
The prime mover is a Plessey GDHM32 24 GHz Gunn Oscillator.
In the middle left of the picture is the pre-amplifier coupled to the detector diode by BNC connectors and black co-axial cable, and with similar connections the signal passes to the IF. In the middle foreground is the IF amplifier and audio output.
The design has a wavemeter built permanently into circuit. The detector diode is mounted in the waveguide and closely coupled to a NE 5633 pre-amplifier built into a small box made of copper-clad board.
The wavemeter calibration chart is firmly fixed to the base board for ready reference of frequency.
The Gunn power supply and modulator are constructed in a die-cast box that doubles as the mounting plate for the main waveguide components.
The tripod fixing spanner is held in place with a spring clip. The antenna horn is detachable so that a small dish can be substituted.
This exhibit was last updated on August 19, 2014.