Well, that should absolutely produce some distortion on your local magnetic field. But I'm not sure the towers are the reason of the calibration problem.
In order to work (for mocap) the sensors just need a constant magnetic field, more or less parallel to the ground. Big fixed magnetic distortions do bend the field, but most of the times it's still usable.
In order for the antennas (or other sources) to interfere with the capture their strength and position should be such as to:
- Create a flow of the magnetic field (almost) perpendicular to the ground.
- Neutralize the natural magnetic field
Another type of nasty disturbance scenario is when the source changes it's strength over time, bending the magnetic field in a mutable manner.
Again, I wouldn't say that the towers are causing the issues, but let's gather some data in order to discard that hypothesis.
Use a compass to get the direction of the magnetic north from your home. Compare it with the real north (using something like a satelital picture). Do they roughly match?
On your phone, download Physics Toolbox Sensor Suite (only for android I think, if you have iOS there's probably an equivalent one)
Within the app you should record some data from the magnetometer. To do so go to
(Hamburger menu) > Magnetometer
You will see a screen like this:
Press the big
(+) button to start the capture for both of the following tests
Leave the phone rest for a minute or so on the flat surface. This will help us discard the unprobable scenario of a fluctuating magnetic field
Put the phone on a flat surface, and make four 90° turns, ending on the same direction you started. Between each turn hold it still for some seconds. This will help us determinate if the field has a significant vertical component, in other words, if it's pointing upwars
Please post the files generated after each test.