[sdiy] Hand-matching capacitors for filter stages

[Ian Fritz]

At 02:36 PM 2/9/2010, Andre Majorel wrote:
>On 2010-02-09 11:10 -0800, thx1138 wrote:
>
> > I can tell you that Ceramic and Electrolytic Caps are a real NO
> > due to cap value changing over time and temp.
>
>But *what* ceramic caps ? Z5U or C0G/NP0 ? The latter look pretty
>good and I think someone on the list had success using them in
>place of polystyrene.

Absolutely!  I have tested NP0 quite carefully vs polystyrene in precision 
VCOs and can see no noticable difference.  Specifically, no readjustment of 
tracking or of the HF tracking correction was needed.

I've stayed away from silver mica's because in general they are said to 
have significant soakage effects.

Ian