Here’s the problem:
To create a stable, wide diameter support for the record, that doesn’t move. Conventionally platters have either thickness or a sizeable edge.
The trouble is the standard 1200 / 1210 series platters lack both! We are effectively left with a disc, severe ringing is the natural consequence.
(For proof we need only examine the original metal offering: Place a finger through a hole, tap it gently and “feel” the edge. The all too familiar uncontrolled, vibrating “Klong” confirms the problem: The edge is moving.)
One can try changing material: Glass…ceramics…plastics. In all cases, tap the edge and you can still actually feel movement.
…And if you can feel it, the stylus can read it.
It turns out that this is in fact a difficult problem to solve.
A creative solution was needed: