Hi. I have a Linksys WRT3200ACM with OpenWrt 19.07.4 and a very short 5ghz WiFi range.
This is /etc/config/wireless (5Ghz side)
config wifi-device 'radio0'
option type 'mac80211'
option hwmode '11a'
option path 'soc/soc:pcie/pci0000:00/0000:00:01.0/0000:01:00.0'
option htmode 'VHT80'
option channel '120'
config wifi-iface 'default_radio0'
option device 'radio0'
option network 'lan'
option mode 'ap'
option key 'mykey'
option ssid 'MIWIFI5'
option encryption 'psk2+ccmp'
I know that the router uses Marvell WiFi, so I'm using AES encryption cipher and default country code, but signal range is very poor.