[sdiy] capacitor question.

[Eric Brombaugh]

Ian Fritz wrote:
> At 04:01 PM 6/13/2006, Harry Bissell Jr wrote:
>> Hiya Ian (et al)
>>
>> Of course that is good advice... in the small
>> pF values its almost certain you will get COG
>> / NPO dielectric.  You'll have to work to get other
>> dielectrics.
>
> Mmmm ... XR7 and Z5U seem at least as common.  One needs to check 
> carefully before ordering.

And for those (like me) wondering what the difference between these are:

http://www.rfcafe.com/references/electrical/capacitor_dielectrics.htm

which seems to indicate that if you want tight tolerance and good Q in 
the signal path then NPO/COG is what you need. XR7 and Z5U are basically 
good for cheap/small bypass caps only.

I remember learning this stuff long ago, but then years of ASIC design 
numbed my brain...

Eric

BTW - I notice that Ian's address changed from earthlink to comcast. Did 
you get a fatter pipe?