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Frequency variations in one amplifier stage to other AMPstag - RF Cafe Forums
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| vu2vic |
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Post subject: Frequency variations in one amplifier stage to other AMPstag
Posted: Sun Feb 11, 2007 12:10 pm
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| Lieutenant |
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Joined: Sat Feb 10, 2007 10:08 am
Posts: 1
Location: Banglore |
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I have designed an oscillator using 2n2222A which is generating stable oscillations
at 100MHZ . Then later I designed a amplifer stage for this oscillator by using 2n2222A.
but the output of this amplifer stage I am getting a frequency change of 4 MHZ that
is 96MHZ...I am not able to understand why this is happening and why there is a change
in frequency at the output of the amplifer stage.
To solve this problem I started
looking at different issues like Impedance matching. I designed impedance matching which
improved the output power of the amplifer but the frequency variations are still inchanged.
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| wb9jtk
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Post subject:
Posted: Mon Feb 12, 2007 9:07 pm
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| General |
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Joined: Tue Dec 26, 2006 5:39 pm
Posts: 58
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I assume it is a L-C oscillator, not crystal-controlled.
There are many possible
explanations for this.
Insufficient buffering between the oscillator circuit
and the amplifier circuit.
Feedback from amplifier (need better shielding, power
supply decoupling, etc.)
Power supply regulation (if you have varactors or other
voltage dependant capacitances in our L-C) changes with addition of amplifier
If you post the circuit here on the forum, you will probably get more suggestions.
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Posted 11/12/2012
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