I bought some 433mhz senders and receivers and some 433 mhz antennas. Unfortunately I don't know where to solder the antennas.

Where do I solder the antennas to and do I need special solder wire?

Pictures of the sender module

front, back

Sender front Sender back

Pictures of the receiver module

front, back

Receiver front Receiver back

I tried to solder an antenna onto the sender (into the hole in the bottom left hole in the front picture), this resulted in the signals no longer being sent correctly. I could see that data was sent because the receiver did receive data, but it was not the data i sent with the sender.

  • \$\begingroup\$ The datasheet supplied with the TX and RX should explain. They should also explain why the TX has a missing inductor compared with the one in the listing. If there isn't any such data, learn the rule : no datasheet, no sale. \$\endgroup\$
    – user16324
    Commented Feb 22, 2020 at 14:48
  • \$\begingroup\$ @BrianDrummond looks like the small coil is the antenna, the one missing on the TX module. \$\endgroup\$
    – jaskij
    Commented Feb 22, 2020 at 19:05

1 Answer 1


The problem is not the antenna the problem is that there are some components missing:

According to my knowledge, the transmitter you sent is missing an L2 inductor coil (the brown coil thing) and the receiver is missing a regular inductor. Fixing this is simple:

  1. Take an enameled copper wire and do three turns with it to make some kind of coil then solder it to the two spots on the transmitter (not the one on the bottom left that is for the antenna).

  2. For the receiver just use an 1 uH inductor (the one that kind looks like a resistor) and solder it on the corresponding spot. (use a image as reference)

  3. Make sure that the antenna you attach is a 17.3 cm long solid wire cable (preferably perfectly straight).

enter image description here


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