# Measurements

### Dummy loads

A dummy load consists of a non-inductive resistor having a dissipation equal to the expected output power. Such a dummy load would have a resistance of about 50 or 70 and may consist of a parallel or series/parallel connection of carbon resistors; for example, ten 5W 680 resistors may be connected in parallel to provide a 50W 68 load which would be satisfactory for a 75W input transmitter. The dissipation of the load may be increased by immersing it in oil. A dummy load should be screened.

On the left, a home made dummy load (screening cover removed). The load consists of 20 x 1k 3W resistors in parallel. The LED near the input connector lights in the presence of over 0.5W of RF. The load is useable up to about 500MHz. To the right is a commercial unit.

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