I have an old Billion 7800N that I am trying to re-purpose as a Wireless AP (preferable as an extender and not a repeater) for the front of my house. I plan to connect it to my Archer VR1600 via powerline adapter and would be grateful for any help on the required settings for each device.
Please note I have searched the internet and the advice I have seen was to ensure that the IP address for each device did not conflict, they have different SSID's and to turn off DCHP on the Billion which I have done but I am still unable to see the Billion router in my wifi networks on my phone or any other device.
You should see the Billion wifi network regardless of the rest of the setup. Here is an article about setting up the wifi. Looks like it is a single band only. Don't hide the SSID.
If you use the same SSID as on Archer but on a different channel, you can move around the house and the device will lock to the stronger signal without having to reconnect to a different network.
Disable the wifi on the Archer; button on top edge of router.
Do factory reset on Billion, logon to it and make sure wifi is enabled and sending SSID.
Experiment with the Channel ID settings.
If you still can't see it, the wifi may be broken.