What antenna for spitz

Hi all, just interested to know what kind of external antenna you are all using? And what kind of increase you see from the standard antennas?

I’m have a blue spot 4g5g but it only has 2 antenna, by mixing and matching I could double my upload speed to about 70mbps but download actually dropped a touch. I expect that’s because it’s not the right antenna for this device.

What do you use?

We have some recommendations GL-X3000 / Spitz AX - GL.iNet

Those antennas are not cheap though.