14 Jun 2010

Twin tee oscillator

A twin-tee audio oscillator is a very useful item to have around the shack. Looking around the net for suitable circuit values yesterday I came across this page by G0XAN http://homepage.ntlworld.com/g0xan/twin-t.htm

I shall be using one this week with my CW keyer to send slow CW (QRSS) on 1.2kHz and 8.97kHz. For very slow CW I'll need a much more stable oscillator probably a crystal and digital divider, although many on the "Dreamers Band" are using a DDS source.
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2 comments:

  1. AnonymousTue Jun 15, 11:38:00 am GMT+1

    Howdy,

    I see the twin-t oscillator information on the G0XAN site is incomplete.

    In the drawing of the twin-t oscillator embedded in your post, the following sets the frequency:

    R1=R2=Rx
    R3=Rx/K
    C2=C3=Cx
    C1=KCx
    F=1/(2*PI*Rx*Cx)
    K>2

    See Here:
    http://en.wikipedia.org/wiki/RC_oscillator

    Here is a better (IMHO) albeit more complex circuit:
    www.discovercircuits.com/Andy/Twin-Toscillator.pdf

    73's David WB4ONA

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  2. crystal oscillatorWed Jul 07, 08:23:00 am GMT+1

    Impressive with thanks!

    ReplyDelete