Why Use RF Dummy Load on VTX, Radio, and Antenna


On this article, we’re diving into using RF dummy hundreds for VTX (video transmitter), radio transmitters, and Triple Feed Patch antennas. These gadgets are self termination circuit with a 50-ohm impedance and an SMA/RP-SMA connector, that are used for dissipating RF vitality. Generally known as “RF terminations,” they play a vital function in safeguarding your tools.

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RF dummy hundreds could be bought from numerous distributors, together with:

Eradicating antennas out of your FPV drone and radio makes it simpler to pack for travelling. Nevertheless, powering them up with out reattaching the antennas can result in vital issues.

Additional Studying: TX16S Detachable Antenna Mod

When antennas are absent, the ability from the transmitter displays again into its output circuitry, probably inflicting fast warmth build-up and injury, notably to the output transistor. Some radio transmitters could provide inner safety and warnings if an antenna is lacking, however it’s all the time higher to err on the facet of warning.

Picture credit score: SnowLeopardFPV (https://intofpv.com/t-homer-simpson-moment)

RF terminations, or dummy hundreds, are glorious for safeguarding transmitters whenever you select to take away the antenna, whether or not it’s a 5.8GHz VTX or a 2.4GHz/900MHz RC transmitter. These small and cost-effective gadget not solely shield your tools if you happen to neglect to reattach antennas but additionally maintain the SMA connector free from mud and particles.

Curiously, dummy hundreds could be helpful for altering VTX channels within the subject. Since they emit considerably much less sign than a correct antenna, they reduce interference with different pilots.

Dummy hundreds are notably helpful for Triple Feed Patch antennas (product web page: https://s.click on.aliexpress.com/e/_DdxtiWD). These antennas include two outputs, RHCP and LHCP, however usually, just one output is used at a time. It means that you can swap between these polarizations any time you need. Attaching a dummy load to the unused output prevents sign leakage, thereby enhancing the antenna’s efficiency and effectivity.

Triple Feed Patch Antenna with Dummy Load on One Output

Earlier than utilizing a dummy load, it’s advisable to check with a multimeter . Measure the impedance between the center pin and the skin. A correctly functioning dummy load ought to present a studying round 50 ohms. This easy examine ensures your tools capabilities optimally.


Incorporating RF dummy hundreds is helpful for safeguarding VTX, radio transmitters, and optimizing sure kind of antennas, providing a easy but efficient answer to boost your FPV tools’s longevity and effectivity.

Edit Historical past

  • Jun 2021 – Article created
  • Dec 2023 – Up to date


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