NVG510 Wireless won't turn off

I have this NVG510 modem/router. I have gone in and turned off the wireless but it still seems to be transmitting without an SSID. There are only 3 good channels for wireless. I cannot afford a turned off device to transmit and chew up a good channel. Is there a way to really turn off the transmitter? Is there a replacement modem I can buy? I have a VIOP phone which might complicate things.