Polypropylene capacitors can actually self-heal to such an extent that
there's little left of them. The melting point of polypropylene is not very
high and they can end up as just a liitle blob of plastic.
Don't worry though, I still use them suitably rated for the frequency in
use and most of them are 600Vac or more.
73, Hugh, M0DSZ
Receiving the following content -----
Re: LF: TXing WSPR/MF on an indoor loop, part 2
In my experience these polypropylene capacitors when
they fail, they
just lose some capacitance. I think they call it 'self
they imply that when they fail there is no short
I have some really nice silver mica capacitors (ex MW
that would be perfect for this task...
Anyway, I am
slowly gearing up for some VLF action over here. The
other day I did some
tests at 16.72 kHz into an ugly loop (very
roughly 120 metres by 3 metres,
single turn) and I was able to receive
my signals using an unoptimise
ferrite antenna at a bit over 2 km from
the TX. I don't think I am in the
near field at that distance, am I?