I am currently looking into building a custom RF transmitter. The commercial ones built for Arduinos usually operate at 5V. I was also looking into some RF remotes, and found that they usually use 12V. I am wondering if this creates a difference in terms of RF output power?

It kind of makes sense for Arduino modules to run on 5V since that is a voltage the Arduino can supply, but would using a 12V circuit improve the output power?

  • \$\begingroup\$ The lower voltage is easily sufficient to reach legal power level limits. What are you actually trying to accomplish here? What frequency, modulation and purpose, and what regulatory allowance are you hoping to operate under? \$\endgroup\$ Dec 30, 2020 at 21:30
  • \$\begingroup\$ Hi Chris. I am dealing with 433 MHz ISM band. Modulation is OOK. I am trying to see how much I can extend the range of the transmitter. \$\endgroup\$ Dec 30, 2020 at 21:34
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    \$\begingroup\$ You an easily hit the legal power limits for 433 with even just 3v3 supply. And if your protocol is OOK, you're not going to go very far. Buying a decent synthesized radio with an SPI interface rather than the usual monstrosities might help a little, but most of the improvement would be on the receiving side and in switching to a better modulation scheme. \$\endgroup\$ Dec 30, 2020 at 21:37
  • \$\begingroup\$ @ChrisStratton, From what you said, working on increasing the gain on the receiver side is more important. For the purposes of this project, I am trying to keep everything as simple as possible and avoiding components that run on interfaces such as I2C or SPI. \$\endgroup\$ Dec 30, 2020 at 21:44
  • \$\begingroup\$ @aeroengineer in doing so you will be limiting yourself to quite "crappy" radios and so frustrating your goal. The SAW-tx / regen-rx sets with a simply modulation in/out are suitable for short range use only, and ironically require more sophistication to the software decoder, since they "invent" signal all by themselves when there is none. \$\endgroup\$ Dec 30, 2020 at 21:45

1 Answer 1


A better receive antenna may help.

You'll find more information at

433 MHz Antenna - Balanced Dipole + Balun?


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