Why Is My 4x4 MIMO Slower After Moving It Outdoors?

July 29, 2025 1 answer
Asked by CuriousCat123
I recently set up a 4x4 MIMO antenna from Waveform, aiming to connect to a cell tower that's about 14 miles away. Initially, I had the antenna installed in my attic and saw varying download speeds between 5-12 mb/s, occasionally hitting 20 mb/s, with uploads usually below 0.5 mb/s. But after I bought a ~4 ft J-mount and moved the antenna to my roof, I've noticed my upload speeds improved to around 3 mb/s, but my download speeds plummetedโ€”often below 1 mb/s and rarely exceeding 5 mb/s. I'm puzzled about why elevating the antenna, which reduces obstacles in the line of sight, would lead to worse performance. I even considered erecting a 30 ft ham radio tower to mount the MIMO at a higher point, but the folks at Waveform warned me that being higher might actually cause more interference. Could someone explain why this might be happening?

Answers

TechieTom94
It sounds like the antennas on cell towers are usually pointed downwards, so your setup might be missing their signal even more now than before. Since youโ€™re 14 miles away, thereโ€™s a chance that the tower's signals were better directed towards your attic rather than your roof. The higher your MIMO is, the more you might lose that direct connection with the tower if the angles arenโ€™t right.

SkyWatcher77: Exactly! And donโ€™t forget about the horizon curvature. If the towerโ€™s antenna is at around 100 ft, it might only barely be visible from your location, as it's on the edge of the line of sight.

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