Dummy loads are used within amateur radio to dissipate the power from a transmitter without radiating it. When testing the transmitter, setting it up or whatever, a dummy load will be particularly useful.
When selecting an dummy load to buy there are several points that may be of interest:
- Frequency range: Dummy loads have a limited frequency band over which they can operate. Typically they will be able to operate down to DC, but the top limit is often limited by the inductance of the resistor. This will be indicated as the SWR that they exhibit at a certain frequency. Check the dummy load being bought can operate up to the frequencies being envisaged.
- Power capability: It almost goes without saying that the power handling capability of the dummy load should be checked before buying. Check also whether the handling capability is continuous or for a short period only. Match its power handling capability to your requirements.
- Size: Dummy loads that can handle higher power levels and those which can handle the power continuously will naturally be larger. They will also need air flow to enable them to cool. Before buying the dummy load, check the size is compatible with your requirements.
There are many different dummy loads that are available to buy for amateur radio and other applications. There is a good selection so it will be possible to choose one that fits the requirements well.