[hpsdr] crystal Oscillators

[Chuck Hutton]

While that's true for some odd cuts of crystals, the popular AT cut (when
outside its flat area) increases in frequency with increases in temp and
decreases in frequency with decreases in temp. 

Take a look at the bottom chart on this page:
http://www.citizen.co.jp/english/crystal/aspect/index.html


Chuck

Date: Thu, 14 Jun 2007 17:26:24 -0700 (PDT)
From: FRANCIS CARCIA <carcia at sbcglobal.net>
Subject: [hpsdr] crystal Oscillators
To: hpsdr at hpsdr.org
Message-ID: <685290.32796.qm at web82312.mail.mud.yahoo.com>
Content-Type: text/plain; charset="iso-8859-1"

Most crystals flip over at about 30 degrees C meaning above and below that
temperature the frequency will go down. Heating or cooling has the same
effect on either side of the slope. 
  I prefer the option to use my own VCXO having a few. This would allow the
user to upgrade if desired. 
  My USB2 card is in the mail and breadboard almost built so hope to power
up some time next week and join in the fun. I'm mounting a couple linear
power supplies and Atlas on a plate until I decide how I want the final
package. Frank WA1GFZ


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