The ESR transmitter is modular in design, using 16 small klystrons based on TV transmitter technology. The transmitter has a central operating frequency of 500 MHz. At the time of writing this article, the two dishes cannot be used exactly simultaneously. However it is possible to alternate between the dishes on a timescale of approximately 5 seconds. Two receiver systems are available which (for instance) allow ion line and plasma line data to be recorded simultaneously.