Kyle
Hey
Im not too hot on the techie side of this, but basicslly tv/radio interference is caused by the sparking of the brushes against the commutator. The supressor is basically a smoothing capacitor to counteract this.
All UK Hoovers from the late 50s onwards were fitted with suppression, and there were kits fitted by Hoover service stations to older machines(these were fitted by the switch in the handle normally- the supressors were mini versions!). Strictly speaking it was illegal to cause interference but I doubt this was often if ever enforced.
I dont know if any US machines have anything similar? I know the 1010 and 707 Convertibles I have dont appear to.
Hope this helps!
Seamus
