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    Radio Circuit Analysis

    How would I go about analyzing a circuit such as the one below? I have a few questions to start with: 1) Do you consider the antenna an AC voltage source? 2) What is the purpose of C2? I'm assuming it's to reduce noise, but how exactly does it accomplish this? 3) If I wanted to use an NPN...
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    Oscillator output

    Just a quick question or two.... does the sine wave output of a hartley oscillator (or colpitts or another sinusoidal output oscillator) create AC (does the output voltage go negative)? Or is it just DC with voltage moving smoothly up and down? Also, if I were to take a 1MHz signal from a...
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    Help with radio circuits

    Yeah there were a few sites in there that were kinda useful...though nothing that really explained how antennas work going WAY down to the basics. I'm still confused about how an antenna creates a current out of an EM wave hitting it...or does it? See I'm a little boggled about how antennas...
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    Help with radio circuits

    Electronics Resources? We have a section like that? Link me please =) I just found an article section and didn't find much there on radio electronics. :) [EDIT] oh stupid me he was referring to the forums. Hey, good idea ante, thanks. Will definitely check that out.
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    Help with radio circuits

    Despite the fact that I really appreciated the help you offered
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    Help with radio circuits

    Hey again guys, in need of a bit of help again. In my robotics class at school (which basically turned out to be a electronics/ infrastructure physics class) we have a summative project due at the beginning of june, and I've got a great idea for the project (mine is a new security feature for a...
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    Inductance of a coil

    Don't worry about it, I found out. It's about 450 uH Thanks for the help though  ;D
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    Inductance of a coil

    I need to build a coil with these specs: 1 inch length, .5 inch diameter, ferrite core, 30 turns of 22awg wire and 3 layers. Can anyone give me a pretty accurate measure of the inductance of that coil? This is for a capacitor charging circuit, and I've done a few calculations of my own but I...
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    Transformers

    Just a quick question: Lets say I have two transformers, one with a 2:1 voltage ratio and one with a 3:1 voltage ratio. If I were to hook these up so that the voltage gets increased twice, would the output voltage be 6 times as much as the input? Would the current follow the same pattern as...
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    High Voltage Cap charger

    Hahahah its ok Audio, you've helped me enough over time that it compensates for that minor error thanks again ;D Oh yeah just one more thing: The output of the rectifier will still be pulsating rather than constant voltage, will that affect the charging of the capacitor? Is there any way to...
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    High Voltage Cap charger

    So the idea is plausible then =) Great. A small current of 1.8mA doesn't worry me, I have all the time in the world to charge a cap
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    High Voltage Cap charger

    Hey guys, just doing some research into converting voltages, and I was just thinking: Would it be possible to say hook up a 9v battery to a IC555 timer, and connect the output of that timer to the primary winding of a transformer and connect the secondary winding to a high voltage capacitor...
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    Simple transistor question (probably)

    Hey again everyone, just one simple question about transistors: Why do people say something like 'a transistor typically has .6V from its gate to its emitter and .2V from its collector to its emitter'?? Doesn't the voltage get determined by the rest of the circuit? Like for instance, if I put...
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    Op Amps gain

    Ok one last thing: I have a picture of a circuit here, and there is an opamp used, but there is no negative feedback to lower the output voltage Lets say the voltage across the resistor in the phototransistor branch is 1V and the voltage across the phototransistor is 11V when there is no...
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    Op Amps gain

    Thanks for the help audio, but aren't bels arranged in a logarithmic scale? So wouldn't 60dB (6Bel) be a gain of 1 000 000 (10 to the power of 6)? You said that most opamps have a gain of around 100dB, resulting in a voltage gain of 100 000. Does that really mean the output of an opamp with...
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    Op Amps gain

    Ok, if the data sheet for a differential op amp says 100dB, then that means a power gain of 10 000 000 000 right? Holy SMOKES! That can't be right. The way I figure that huge number is 100dB = 10B right? And the way to get the ratio gain from B is to put 10 to the power of the bels, so 10 to the...
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    Inductance

    Got it from this awesome tutorial...But I think I solved my problem while you guys were rambling on about misplaced posts  ::)  hahahahah I misread the symbol H as meaning henries, where it is actually the symbol for magnetic field intensity, just like L is to inductance. Magnetic field...
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    Inductance

    I have a question about inductors. Inductance is the same thing as Field Intensity right? They are both measured in Henries. So then why does one formula for figuring out the field intensity rely on the current put through the coil and one doesn't?? Heres one formula : L = ((Number of Turns)
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    Laser Parking Aid Schematic

    Lately my parents have been having a hard time parking their car in the garage because of visual obstructions. I have a circuit here that will use a 5v power supply (probably plugged into the wall, batteries wouldn't last long enough) --d1 is a laser pointer --r1 dissipates .5V so that d1 runs...
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    Ok, only one more question about transistors, I promise!!

    Ok, now that I've got the hang of what they're for, and things like DC gain and such, how would you design a circuit and figure out the specs for your transistor? For instance take this circuit for example: How would I go about figureing out values for Q1? Would I use Ohm's law, Kirchoffs...
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