A raspi kernel patch to remove wifi restrictions for the ath9k driver, intended for AR9271 WiFi dongles such as TP-LINK TL-WN722N.
Warning: this is illegal if you operate without the proper radio licenses, such as a ham radio license. The patched driver will allow you to apply frequencies and powers that are outside of typical ISM allocations and ham radio allocations in certain countries, so please cross-check with your local regulations.
Based on a similar script inside hatsunearu/EZ-WifiBroadcast, for desktop/mainline kernels. Should apply to 4.4.y and the 4.9.y branch of the kernel on the official raspi Linux repo.
To build for targeting the raspberry pi 1/zero, consider rpi_wifibroadcast_image_builder.