CPF901 router only appears to use one WiFi channel

Installing and Using OpenWrt Network and Wireless Configuration
1

I have a Chinese router marked as CPF901 which uses the QCA9531 WiFi system and reports Model U9531-01 in the system status. The router has two WiFi aerials, one for each channel on the QCA9531, however only one aerial seems to do anything so my question is :-

Does OpenWrt 15.05.1 r20 actually use both channels of the WiFi module as it appears not as I can remove one aerial and the status report gives the same value for WiFi reception, but removing the second aerial loses the signal.

Looking atthe datasheet for the QCA 9531 it is shown as having 2.4 and 5GHz capability whilst the router only seems to have 2.4GHz available.

2

OpenWrt v15 hasn't been maintained for years and is known insecure. It might be that they are using Qualcomm's QSDK, which is loosely based on that ancient release. You'd likely have to contact the device's vendor for more details on their firmware.

QCA9531-based devices supported by OpenWrt generally support both radios.

$ ls -1 target/linux/ath79/dts/qca9531_*.dts
target/linux/ath79/dts/qca9531_comfast_cf-e313ac.dts
target/linux/ath79/dts/qca9531_comfast_cf-e314n-v2.dts
target/linux/ath79/dts/qca9531_comfast_cf-e5.dts
target/linux/ath79/dts/qca9531_engenius_ews511ap.dts
target/linux/ath79/dts/qca9531_glinet_gl-ar300m16.dts
target/linux/ath79/dts/qca9531_glinet_gl-ar300m-lite.dts
target/linux/ath79/dts/qca9531_glinet_gl-ar300m-nand.dts
target/linux/ath79/dts/qca9531_glinet_gl-ar300m-nor.dts
target/linux/ath79/dts/qca9531_glinet_gl-ar750.dts
target/linux/ath79/dts/qca9531_glinet_gl-x750.dts
target/linux/ath79/dts/qca9531_tplink_archer-d50-v1.dts
target/linux/ath79/dts/qca9531_tplink_tl-wr810n-v1.dts
target/linux/ath79/dts/qca9531_yuncore_a770.dts