I agree, that is why I did not suggest cable but rather rods for biasing the load. And the load should be biased rather than equally distributed or harmonics can be expected. A natural bias occurs when two rods are used as I described. The steel pipe should not need a third opposing tie down but if it does it should be a foot or two below the southern two to help dampen any ringing and resist harmonics.

Knew a guy that used piano wire for a secondary support. Made slightly smaller diffraction spikes but when a neigbor turned on his radio, Saturn kept time to the beat.

Cheers,
-Rick