This tripod mounted 10 GHz wide-band tranceiver uses the waveguide 16 as the main fixing support and the antenna is an 18 inch diameter aluminium dish fitted with a 'penny feed'. These dishes were made available by Practical Wireless for the 1981 PW EXE project and this rig was built in 1984 by G3LYP.
The IF is at 100 MHz and utilises a FM broadcast transistor radio. Additional to the broadcast receiver the RX uses a 40673 dual-gate MOSFET preamplifier.
The Gunn tuning is achieved with a threaded PTFE rod that passes into the oscillator cavity. Initially designs used micrometer heads to adjust the penetration of a rod into the oscillator cavity but once it was found that PTFE rod machined to a 4 BA thread offered a simple and effective tuning arrangement this method was adopted for many tranceivers.
The RF section consists of a Gunn oscillator and in line mixer to a G3RPE design. The Gunn is modulated by a 7805 regulator with the AF applied to the common terminal of this three legged regulator. The audio available is either speech or single tone.
This exhibit was last updated on August 19, 2014.