Keep in mind, installing the beta firmware will leave your router open to vulnerabilities, that have only been fixed in a later firmware.

@tnabeel The MR600 has two female SMA connectors.

@Overdale It should work, but make sure that it is a stabilized 12.0V supply and doesn't directly apply 13.8V from the battery.

Yes, the software support is dissapointing. Firmware bugs that I've reported in January hadn't been fixed in the June firmware update either.

Situation here is B20 is strong but slow (-80 dBm, 5 Mbit/s), B3 weak but fast (-101 dBm, 75 Mbit/s). But with a single antenna it doesn't make use of band 3 at all and always choses B20.

At least for transmitting it is only using one antenna in my case, even if both are attached (confirmed with spectrum analyzer and h-field probe). When both antennas are connected, the MR600 shows...