First of all, hello to all ! I just registered on this forum after lurking for a while. I've been interested in electronics for quite awhile but only got to really study it in detail after I joined my local Ham Radio club. I'm currently using the 2014 ARRL Handbook to teach myself radio technique, and I'm loving it! But there a few things I just can't wrap my head around :/
One of these things is oscillators. The 2 circuits in the attachment are taken directly from the handbook.
I don't totally understand how A) works. The way I see it, some noise will make its way into the LC tank circuit. The LC circuit will filter it, and at the beginning I will have a very small amplitude sine wave of frequency 1/(2∏*√LC)) at the entrance of my amplifier. The amplifier which has unity gain will produce the same signal and inject it into the LC circuit. So now Vtank = V1. If I understand correctly, I'm constantly adding more energy into the LC circuit, thus raising the amplitude of my sine wave. At one point though won't the amplitude become so great that the amplifier saturates and I'd end up with a square-like signal at V1? And wouldn't injecting V1 anywhere in the tank circuit work aswell?
B) is also a mystery to me. Part of the reason is because I don't really "get" A) But also, I understand we have an RF choke to prevent the AC signal to go to ground instead of our output, but why do we have an RF bypass at the Drain?
Thanks in advance for taking the time to help !
One of these things is oscillators. The 2 circuits in the attachment are taken directly from the handbook.
I don't totally understand how A) works. The way I see it, some noise will make its way into the LC tank circuit. The LC circuit will filter it, and at the beginning I will have a very small amplitude sine wave of frequency 1/(2∏*√LC)) at the entrance of my amplifier. The amplifier which has unity gain will produce the same signal and inject it into the LC circuit. So now Vtank = V1. If I understand correctly, I'm constantly adding more energy into the LC circuit, thus raising the amplitude of my sine wave. At one point though won't the amplitude become so great that the amplifier saturates and I'd end up with a square-like signal at V1? And wouldn't injecting V1 anywhere in the tank circuit work aswell?
B) is also a mystery to me. Part of the reason is because I don't really "get" A) But also, I understand we have an RF choke to prevent the AC signal to go to ground instead of our output, but why do we have an RF bypass at the Drain?
Thanks in advance for taking the time to help !
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