Dummy Load

Overview

A dummy load is a non-radiating 50 ohm termination that absorbs transmitter power as heat. It lets you test a radio, set up a tuner, adjust a speech processor or check a new amplifier without putting a signal on the air or annoying anyone on the band.

The specification that matters is the combination of power rating and duty cycle. A 100 W load with a modest heatsink can handle a brief tune-up but will overheat under sustained digital-mode transmission, where the carrier is on continuously. For FT8 or RTTY testing, derate the load heavily.

Bands and modes

Band coverage

Modes

Safety note

Using it well

• Use it for every test that does not need to radiate.
• Derate to roughly a third of the rating for continuous-carrier digital modes.
• Check the load is warm, not hot, after a transmission — heat is wasted power.
• Keep a small load in the go-kit for field repairs.