Loading Capacitors

[w5gw]

Has anyone used 1600V Metalized Polypropylene Film capacitors in place of micas in a switched Pi-Net loading configuration such as a Viking Valiant?

[w4bfs]

you need an rf current rating for a part in that application .... I don't think you will (I could be wrong) and if you go ahead and try it, be prepared for letting out magic smoke

[Pete, WA2CWA]

Typically, plastic (polyester, polypropylene, polystyrene) capacitors use a thin wound plastic sheet as the dielectric.
Plastic capacitors, in general, are used in practically all types of applications including coupling, bypassing, filtering, timing, noise suppression, and power factor correction. They may be used over frequency ranges to 10 megahertz or greater, depending on capacitance value and construction. However, unless those caps are designed for high RF currents, applying RF power to them could send them into orbit.