[sdiy] Re: cap autopsy

[Dave Krooshof]

Blast, my original reply did not show up here!
OK, quick retype...

Scale problem: I did meant mm, but I'm quite sure about the microfarad.

>>2700
>>10%
>>250-
>>
>>It's grey, some 3x12x8 mm. Letters are black.
Yes mm...
>>Normally you would expect its value to be in picofarads,
>>But I think this is a 2.7 microfarad cap.

>Dave, is there any brand name on the cap, or any logo?
I just noticed I managed to overlook that it says "MMK" on the cap.

>If you relly mean millimeters, it sounds like a
>ceramic, 2700 pico with -250 parts per million temperature drift.
Aha. Ceramic!
pico... hmmmm.... A 3.2 mu worked okish, 2.2 mu did not quite!

>>Does anyone have a clue what this might be?
>>Value here is the secundairy problem. As this oscillator is loved for it's
>>instability (as in not stable) I'm primairily interested in what this
>>cap is phisically/chemically/brandwise

>I am afraid that if the instability is due to the cap,
Not only...
>then the cap is faulty
>(no matter waht kind or value it is) and another cap of the same
>value and type will not produce the effect you seek.
nono! The instability is what I need: It's too stable now,
it doesn't go into oscillation easy enough. I have too little uncontrol now.
The proper cap should make it more instable.
It's a wild thingy with it's own will.
That's why I need a cap made of the same stuff!


Thanks for researching with me guys!

Dave

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Dave Krooshof http://www.xs4all.nl/~krooshof
geluidstechnicus @ http://www.ahk.nl/the/theatertechniek_ov.html
webmaster: http://www.popronde.nl
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