View Single Post
  #2   Report Post  
Old June 11th 06, 07:31 PM posted to rec.radio.amateur.homebrew
Dave Platt
 
Posts: n/a
Default schematicxdiode-capacitance

In article ,
mocio_Vileda wrote:
I need a capacitance meter scheme to test just varicap and several diodes
,
has anyone link(s)?


Check out the AADE meter (www.aade.com) - it's the least expensive
decently-accurate meter system I know of. I understand it's a kitted
version of a project described in an electronics or radio magazine a
few years ago (I don't know where the article appeared). A complete
schematic is in the manual, which can be downloaded from AADE's site.
The kit is (in my opinion) extremely well thought out; the meter I
built went together in about an hour, worked first time, and behaves
just as AADE says it should. *Very* nicely done.

The little-or-no-extra-equipment approach would be to wire up your
varicap arrangement in an oscillator circuit, resonating against a
well-known inductance, and measured with a frequency counter or
oscilloscope. Getting good accuracy in the face of all of the unknown
parasitic reactances of such a circuit is going to be a huge headache,
though.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!