Hi Chris,lf,
these capacitors are not bad,they are just not ment for resonant or other
critical aplications,just for coupling and decoupling,
73 gl
Victor
-----Oorspronkelijk bericht-----
Van: [email protected]
[mailto:[email protected]]Namens Chris Trayner
Verzonden: maandag 10 januari 2011 16:35
Aan: [email protected]
Onderwerp: Re: LF: Re: Capacitor warning and First 500kHz Class E
breadboard
Hi Andy,
> I resurrected a 10n one from the waste bin, connected the C meter (10.9nF
at Room Temp) and turned a hair dryer on it. C reduced to 5.4nF as I was
watching, and that was probably only around 50C.
> Blowing on it shifted the value noticeably.
I have a batch of very bad (high temp coef) 22nF I sometimes use for
undergrad teaching. Get the students to build an oscillator with them, watch
the waveform and then grip the cap between thumb and forefinger. You can see
the square wave width change visibly - you don't even need to measure it to
realise it's happening.
73,
Chris G4OKW
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