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Question about transister signal and biasing voltages

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obrien135

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I purchased the attached circuit as a kit and assembled it. The signal on the output buffer stage doen't quite seem right. The base about at the right dc level (around i/2 the supply voltage) but it is distorted. The top is clipped off. I don't have a way of capturing the waveforms but I'll try to draw them. THe signal on the base is smaller and at a dc of about 1.5 to 2 volts lower. The collector has a signal about equal to the emmitor but riding on the supply. Does this mean the transister is bad? The signal going into the buffer looks distorted but I'm not sure if the distortion comes from the oscillator or the buffer.





It is being supplied by an LM317 circuit but the load current is much less than 1.5A. I don't know why the supply is affected that way. Maybe I chose the wrong value resisters. I used the formula on the data sheet, but maybe I didn't get it right. I should be going up to the place where the circuit is kept later on today, so I'll look into that. The voltage suppying the LM317 input is a 13.8VDC battery eliminator that can handle up to 3A. The load is a toroidal transformer with about 10 turns on the primary and about the same on the secondary, which is terminated with 75 ohms. The AL facter is about 3000mH per 1000 turns. So the load current should be fairly low at 3MHz.


See attached file for voltages and signals:


View attachment 3 MHz oscillator.bmp
 
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