[sdiy] Tempcos of Xicon and LCR polystyrene caps

[Ian Fritz]

At 03:24 PM 6/14/2006, Andre Majorel wrote:

>Mouser has cheap polystyrene caps (Xicon 23P series). The data
>sheet does not give a figure for their tempcos, but looking at the
>graph, the slope is about -250 PPM/°C at 25°C.

That's interesting.  I have a collection of misc PS caps of unknown origin 
that I use.  I have seen VCO cores with drift around -250 ppm/K and never 
understood why it should be quite so large.  This may be the answer.


>The LCR FSCEX polystyrene caps are five times more expensive. That
>may be because they are more precise (1% vs. 5% for the Xicon
>parts) but they also claim -50/+110 PPM/°C.

Do you have a link for LCR?  I can't seem to find them.  Thanks.


>The Panasonic ECHS PPS (*not* PS) caps perform as well as the LCR
>FSCEX (i.e. 0.04 Hz/°C at 440 Hz) for slightly lower price.

Polyphenylene sulfide.  Has anyone tried these in VCO applications?  They 
seem a bit lossier than polystyrene.

   Ian