4g Zyxel gets better SNR while I touch the back of the case?
So as a child I remember often a fuzzy FM radio station would improve quality if you just held the antenna with your hand. I am setting up a Zyxel M7460-M608 4g router with built in directional antenna. It is specced up to 600mb down and 50mb up and I am getting 2-10mb down and 2mb up so far. What is crazy as I can physically see the cell tower which cannot be more than 300 metres away, direct line of sight.
I can see the SNR varies between 2 and 4dB, except when I am holding the metal back of the casing, then it briefly goes as high as 10dB. I cant try a speed test at the moment while holding the antenna as I have to go up a ladder to hold it and the laptop is indoors.
I have zip tied it to a cast iron drain pipe, with a metal bracket so the casing does touch the drain pipe.
How can I replicate the improved signal response? Is the drain pipe reflecting interference into the antenna? Do I need to mount it away from the drain pipe or insulate it from the drain pipe?