This is a extended post to our popular identify RF remote control article, this post will mainly focus on how to find your RF remote control’s carrier frequency in easiest way possible, there are several ways possible, we will start from the easiest.
Search for official manuals
This one is the easiest approach, because many suppliers will have their product page online, they will have manuals or at least a table showing which frequency they use for the remote model, for example, a quick Google search for Linear Multi-Code 308911 shows the remote is using 300MHz frequency, and you will get other specs as well.
From labels on remote, no tools required
For most remotes legally sold in USA, there will be FCC ID printed on remote’s back, and you can find the FCC ID number easily, if you don’t know how to find FCC ID, please refer to post here.
And after you found FCC ID, you can search for it online, at FCC website here https://www.fcc.gov/general/fcc-id-search-page
If everything is correct, you can then be directed to a page like following, where the in last two columns of table, you can find the remote’s lower frequency and upper frequency. and you can have more details by click the view form button.
Take LINEAR MULTI-CODE remote for example, the FCC ID is EF4(grantee code) XMULTI-CODE(product code), so we got the lower freq. is 300MHz while upper frequency is 310MHz.
The so much difference between two frequencies usually means the remote have different models with different frequencies, so special attention must be paid to.
Some smaller margin maybe because the remote is using old technology, which uses LC oscilloator instead of modern SAW resonator circuit, this one is easy for DIY to make, because the frequency is very easy to tune to.
If using newer SAW resonator technology, the upper and lower frequency should be somewhere near or less than 150kHz (0.15MHz)
Determine by onboard component
If you have no luck finding correct frequency by the above two methods, then maybe you will need to read our article on how to identify RF remote control by onboard crystal components.
Use a tool like frequency counter
The ultimate solution is to use frequency counter to measure transmitter’s frequency, usually you will need to keep transmitter pressed for some period, close to frequency counter, to read the correct frequency, but you will need to buy a frequency counter, in case you need info on how to use a frequency counter, please refer to this article.
If you’re still not sure about the frequency, we can provide free service for customers who will need to develop those remotes, our inhouse spectrum analyzer together with experienced engineers will give you the most accurate information possible regarding the frequency.