# RF Receiver for 433mhz and 315mhz?

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


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.

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.

• 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. – user101882 Feb 28 '16 at 22:21
• You can sniff 315 and 433 both with the 433Utils RFSniffer – kspearrin Feb 28 '16 at 22:56

The receiver you have can only receive 433 mhz signals. See the white dot to the left of "433MHZ"? That indicates that it is already tuned to 433. You'll need to buy an additional 315 mhz receiver if you want to receive those signals.

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.

• Can you provide a resource that shows me how to do that? – kspearrin May 20 '15 at 3:15
• @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. – Andy aka May 20 '15 at 7:34