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From: crisp@uncecs.edu (Russ Crisp)
Newsgroups: sci.electronics
Subject: How to read the value of small ceramic capacitors, and Why use an IF?
Message-ID: <1991Mar11.181039.22769@uncecs.edu>
Date: 11 Mar 91 18:10:39 GMT
Organization: UNC Educational Computing Service
Lines: 19


Hello again fellow networkers.
I have 2 simple questions I hope someone can help me with.
The first, how do you read and understand the values printed on
small valued ceramic disc capacitors?  There seems to be a
pattern on some I've seen.  For instance, 103 means .01uF,
and 104 means .1uF - I think-.  This pattern doesn't seem to 
hold
on  other values.  Anybody got a clue?

Secondly, why is the rf in a radio receiver mixed with a 
local oscillator to provide an IF?  Why not go straight
through with the carrier frequency?  What advantage does
this IF signal provide?

Thanks.  I appreciate all your responses.  
Russ Crisp
Western Carolina University
Cullowhee, NC