[R-390] killer and mica caps

[Jacques Fortin]

Hi Renee,

I'm sorry but... some have to find a fuse that can blow fast enough to
protect the R-390A mechanical filter(s) input winding, and this is not an
easy task.
It's like trying to protect a transistor with a fuse: usually, the
transistor will blow first to protect the fuse...
I prefer to rely on a very good capacitor there (such as a WIMA MKP10 10nF,
5%, 630V).
And if ever the very worst happen, there is a way to rewound the input coil,
right ?

73,
Jacques, VE2JFE
Montreal

-----Message d'origine-----
De : R-390 [mailto:r-390-bounces at mailman.qth.net] De la part de Renee K6FSB
Envoyé : 10 octobre 2016 22:41
À : Francesco Ledda <frledda at att.net>
Cc : r-390 at mailman.qth.net
Objet : Re: [R-390] killer and mica caps

I am beginning to think that a fuse in series with the cap on the filter
side might be the answer . just a thought .......
Renée, K6FSB

Francesco Ledda wrote:
> Given the small bandwidth of the IF, the frequency/gain variation created
by the cap is negligible.
>
> Frank
> K5URG
>