# Adding additional frequencies (TX/RX)
Official firmware now uses a different method for region locks. Per Aleksandr Kutuzov (skotopes):
```
Mobile app uses Phone/SIM region with fallback to GeoIP.
Desktop uses GeoIP and fallback to System.
```
This data is stored in the `.region_data` (hidden) file within internal storage and is set when connected to Desktop/Mobile per above.
If you're having issues with regional retrictions that do not match your region, you can use the `region_data_null` file here.
Simply download and rename it to `.region_data` then replace the one currently in your internal storage.
NOTE: This _will_ be overwritten each time you sync to the mobile app or qFlipper! **Use strictly for testing/verification purposes.**
## Note: You must be on the latest release!
Some changes I made to the available frequency settings (including unlocking them all). The file is found here:
Officially supported frequencies: 300-348 MHz, 387-464 MHz, and 779-928 MHz (from [CC1101 chip docs](https://www.ti.com/product/CC1101))
Unofficially supported frequencies: 281-361 MHz, 378-481 MHz, and 749-962 MHz (from [YARD Stick One](https://greatscottgadgets.com/yardstickone/) CC1111 docs)
Official & Unleashed currently do not allow anything outside of the officially supported CC1101 specs.
RogueMaster allows unofficially supported frequencies with the `extend_range` file.
**NOTE: Going outside the supported frequencies may DAMAGE YOUR FLIPPER AMP.
Please understand what you're doing if trying to break out of official frequencies.**
You'll need to edit some code and recompile if you want to break outside of the officially supported frequencies. [Proceed with caution.](https://github.com/UberGuidoZ/Flipper/blob/main/Sub-GHz/Restaurant_Pagers/SubGHz_changes.md)
# CAUTION within 402-408 range!
Medical devices can operate here.
## This range is purposefully not included in my file above.
-----
I've had so many asking for me to add this.
 
**BTC**: `3AWgaL3FxquakP15ZVDxr8q8xVTc5Q75dS`
**BCH**: `17nWCvf2YPMZ3F3H1seX8T149Z9E3BMKXk`
**ETH**: `0x0f0003fCB0bD9355Ad7B124c30b9F3D860D5E191`
**LTC**: `M8Ujk52U27bkm1ksiWUyteL8b3rRQVMke2`
So, here it is. All donations of *any* size are humbly appreciated.
 
Donations will be used for hardware (and maybe caffeine) to further testing!
