I have a XD-RF-5V receiver wired to my Raspberry Pi listening with RFSniffer (433Utils). I also have a XD-FST 433.92mhz transmitter wired to my Raspberry Pi running codesend (433Utils).

I can successfully transmit and receive between these two devices.

$ sudo ./codesend 500000
sending code[500000]

$ sudo ./RFSniffer
Received 500000
Received 500000
Received 500000

I also have a 12v 4 channel relay that has a built in RF receiver and came with a remote transmitter. The paper than came with this relay kit says it is operating at 315mhz.

I want to sniff the codes from the remote for this relay kit. Whenever I try to run RFSniffer (433Utils) with the remote, it doesn't pick up anything.

On the back of the XD-RF-5V receiver it says 433mhz, 330mhz, and 315mhz so I would assume it can receive 315mhz signals.

XD-RF-5v Printed Signals

Am I doing something wrong or making incorrect assumptions? Is there something I need to do differently to receive the 315mhz signal? Can this receiver even receive both 433mhz and 315mhz signals (like it says on the back)? I am a bit new to RF (and electrical hardware in general) so I am not really sure how these different frequency devices play together.

  • \$\begingroup\$ my question though is, if you get the 315mhz receiver, would 433Utils RFSniffer read "those* codes? Or do you need a tool that is specific to that (315mhz) frequency as well. \$\endgroup\$
    – user101882
    Commented Feb 28, 2016 at 22:21
  • \$\begingroup\$ You can sniff 315 and 433 both with the 433Utils RFSniffer \$\endgroup\$
    – kspearrin
    Commented Feb 28, 2016 at 22:56
  • \$\begingroup\$ Tip: 'MHz' and 'mHz' are different and 'mhz' doesn't mean anything. Capitals matter! (And 'V' for volt.) \$\endgroup\$
    – Transistor
    Commented Jan 10, 2022 at 17:30

2 Answers 2


The receiver you have can only receive 433 mhz signals. See the white dot to the right of "433MHZ"? That indicates that it is already tuned to 433MHz.

The manufacturer uses the same PCB for each version then indicates which frequency it is tuned to.

You need a receiver for each frequency you wish to receive.


The receiver will only be able to receive one of those frequencies at a time. You will need to tune it to the appropriate frequency using the adjustable core on the inductor.

  • \$\begingroup\$ Can you provide a resource that shows me how to do that? \$\endgroup\$
    – kspearrin
    Commented May 20, 2015 at 3:15
  • \$\begingroup\$ @kspearrin you should locate the data sheet that tells you how to do this. If you can't find the data sheet then my advice is always buy components that have data sheets. This may sound harsh to a beginner but it's a golden rule in electronic component/module selection. \$\endgroup\$
    – Andy aka
    Commented May 20, 2015 at 7:34

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