I've asked my question before, and I am writing this new question with some edits based on my previous problem.  I am building a small FM Modulator ( Transmitting ) simulation on (Multisim). I've used a circuit that I had from Google, and welling to use it for my simulation. Note that this simulation is only for (Educational and Learning Purposes), Therefore, I've replaced the mic and the antenna with some signal generator and oscilloscope or signal analyzer.  The circuit that I used for my transmitter as follows:    When I built that circuit on Multisim, I've made many variable capacitors to notice any changes on the result and how the signal would be effected when the simulation is running.  I've placed function generator with ( Sinusoidal Function ) with ( 1 KHz ) Frequency on the input. On the other hand, The output has both of an oscilloscope and a Signal Analyzer.  the output was weird on oscilloscope. But signal analyzer has almost a Sin function signal same as output. So the system has worked as Integrator, Not a modulator.  Example of the built circuit including the input and output stuff:    After having many changes on the circuit and too many tries, I've tried to add a capacitor attached to resistor in series with a signal generator to check if it removes the DC or ripples. and tried to connect the grounding to the circuit directly.. I had some other weird results as Follows:    Also, I've used another circuit (just a test), Used a function generator on the input, and added a carrier function generator on the emitter of the transistor, and put some oscilloscope to analyze the output as follows:     The output was also weird. Therefore, I guess the problem is how I am using the circuit and how I apply the input and output devices.  As for my information, when I am applying a (Sin) function signal to the input. the modulated output should be as follows:    Any suggestions whats wrong in my circuit and what changes do I have to make to have the expected results?
I am new to the telecom simulations system specially multisim, which I am having a project that I want to simulate.  My project in (Analog Communications) is consisting to have FM Transmitter (Modulator) that accepts a generated signal (Sin, Cos) and get me the modulated output as a Graph.  I've found this FM transmitter circuit (3 km range):   ![two muppets][1]  and I am building that circuit on Multisim, and I failed. Because I faced many problems, first of, the variable capacitor symbol is weird here in the multisim, and the regular capacitor doesn't have variable options. Secondly, when I Use signal generator as (Sin, Cos), the output gets weird after 5 second of the simulation.  I want to show the input signal (before modulation) and the output signal (transmitted or modulated).  I guess my output result where not the as expected, as the signal (Sin with phase 90&deg;) is giving weird result of few seconds of simulating.  Below are screenshots of the simulation results within time.          Any ideas how to edit or fix the above circuit to have this output is similar to what it should be?
What is a concise function that formats a (String) decimal into a currency format in Apex? goal: write the most concise function that formats a (String) decimal into a currency format in Apex. Feel free to trainwreck the code for points, I've kept mine exploded for readability purposes. If $a,b$ are positive integers such that $\gcd(a,b)=1$, then show that $\gcd(a+b, a-b)=1$ or $2$. and $\gcd(a^2+b^2, a^2-b^2)=1$ or $2 $ $\nabla U=0 \implies U=\mathrm{constant}$ only if $U$ is defined on a connected set? This came up in  , but I can't see good documentation or examples that explain how the feature works. When quoting a quotation, how do you handle the double quotes? Assume there is original source text:     This restaurant is amazing with "delicious lasagna" and great service.   Make sure you go 6-7pm for the quietest times.   I want to quote "delicious lasagna" but not sure how to handle the outer double quotes.  If I was quoting more than just that quotation (e.g. is amazing with "delicious lasagna" and great service) I'd just do:     "...is amazing with 'delicious lasagna' and great service."   However, when quoting just that quotation, it looks like:     "'delicious lasagna'"   Is this the correct way or is there something better? Print composer problems Qgis 2.8 Wien with Google Satellite I am having serious problems in exporting a map (Google satellite map) linked to QGIS.   Using the print editor I clearly see the part of the map I want to print and also in the right scale, but when I save it as jpeg, the result is: the correct map in a circle in the middle of the page, and all around it seems that Qgis is zooming at different scale on another part of the map [see attached file].  Any suggestion about it ? I don't want to save it as simple screenshot  because I need an HD file.   ] Undo git pull, how to bring repos to old state How to get client date and time in ASP.NET? Switching back to last *used* tab on Chrome Read-only file system Why is human vision restricted to 400-700 nm? Across the electromagnetic spectrum, 400-700 nm is a narrow spectrum of frequencies and focused in the region of short wavelengths. For example, radio waves cover a large range of frequencies unexploited by the visual system. So what biological reason is there that evolved us to use such a small frequency bandwidth for vision? My question is about one particular usage of static keyword. It is possible to use static keyword to cover a code block within a class which does not belong to any function. For example following code compiles:  public class Test {     private static final int a;         static {         a = 5;         doSomething(a);     }     private static int doSomething(int x) {         return (x+5);     } }   If you remove the static keyword it complains because the variable a is final. However it is possible to remove both final and static keywords and make it compile.   It is confusing for me in both ways. How am I supposed to have a code section that does not belong to any method? How is it possible to invoke it? In general, what is the purpose of this usage? Or better, where can I find documentation about this? Does anybody know how to add the shapefile name to a field in the file's attribute table?  I've found a description:     'You have to use inline variable in CalculateField like %Name% in   expresssion so that whatever the name of the file is, the string will   be inserted based on Name of the dbase file !'   I've tried to CalculateField tool with %Name%, but I got message:  Executing: CalculateField "2011-11-6 15_41_point" DBFName %Name% PYTHON # Start Time: Thu Dec 08 23:34:23 2011 WARNING 000405: No records within table Succeeded at Thu Dec 08 23:34:24 2011 (Elapsed Time: 1.00 seconds)   Where is my mistake? Group of order $8p$ is solvable, for any prime $p$ Consider the following question:     Show that a group $G$ of order $8p$ is solvable, for any prime $p$.   I am kind of stuck, but here are my first attempts:  I chose the series of subroups $G&gt;H_8&gt;H_4&gt;H_2&gt;H_1=\{e\}$ where $H_k$ has order $k$. All of these subgroups exist due to Sylow's Theorems. We have the quotients $H_8/H_4\cong H_4/H_2 \cong H_2/H_1 \cong \mathbb Z/2\mathbb Z$, so $G&gt;H_8\rhd H_4\rhd H_2\rhd H_1=\{e\}$. Only the factor $G/H_8 \cong \mathbb Z/p\mathbb Z$ is causing me a headache, because although its of prime order (and hence abelian) I don't know whether $H_8$ is normal in $G$ (unless $p=2$).  If $p\ne 2$, then the number $k$ of Sylow $2$-subgroups is $1$ mod $2$. Since $k$ divides $|G|$ we might have $k=1$ or $k=p$. If we had $k=1$ then $H_8$ would be the only Sylow $2$-subgroup (and hence normal in $G$). But how could we show this?  Or is there even an easier way to approach this problem?  $\ $  edit: I am going to try a different approach: The case $p=2$ is clear. When $p=3$ or $p=7$ the group has order 24 or 56 and since the smallest simple non-abelian group has order 60, the group must also be solvable in these exceptional cases (as Mariano pointed out).  In any other case we get a Sylow $p$-subgroup $H_p$ of order $p$, which is is normal in $G$. The quotient $G/H_p$ has order $8=2^3$; and prime power order implies solvable. So $G/H_p$ is solvable and $H_p$ is also solvable. And since the composition factors of $G$ are those of $H_p$ together with those of $G/H_p$, we conclude that $G$ is solvable iff $H_p$ and $G/H_p$ are solvable, which is the case. Hence $G$ is solvable if $|G|=8p$. This is a follow-up to this question:   Hans Bethe wrote a paper in 1944, "Theory of Diffraction by Small Holes," Phys. Rev. 66, 163. I don't have access to the paper, but from descriptions online it sounds like he proved the following. Suppose a plane wave impinges on an absorbing sheet, and there is a hole in the sheet of diameter $d$, with $d&lt;\lambda$. Let $P_0$ be the power incident on the hole, and $P$ the power diffracted through the hole. Then the transmission is $T=P/P_0=(d/\lambda)^4$.  As a practical application, I think this explains why microwaves don't leak strongly through the metal grille in the front of a microwave oven.  Questions:   Does the thickness of the sheet matter? From references online, it sounds like the hole is treated as a waveguide...? This seems to relate to cutoff frequencies of waveguides, etc.? It seems to me that Huygens' principle would give $T=1$ for $d\ll\lambda$, since in this limit the wavelets are in phase. Why is Huygens' principle invalid here? Is this related to question #1? Is there a simple argument for the proportionality to $(d/\lambda)^4$? Or if not, how does one prove this using the gory details of Bessel functions, etc.? I need a compact representation of an array of booleans, does Python have a builtin bitfield type or will I need to find an alternate solution? I'm using NetBeans, trying to change the familiar Java coffee cup icon to a png file that I have saved in a resources directory in the jar file.  I've found many different web pages that claim they have a solution, but so far none of them work.  Here's what I have at the moment (leaving out the try-catch block):  URL url = new URL("com/xyz/resources/camera.png"); Toolkit kit = Toolkit.getDefaultToolkit(); Image img = kit.createImage(url); getFrame().setIconImage(img);   The class that contains this code is in the com.xyz package, if that makes any difference.  That class also extends JFrame.  This code is throwing a MalformedUrlException on the first line.  Anyone have a solution that works? How to avoid noisy renders in Cycles? 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Supposedly, using "progressively refine" in the rendering tab should make it refine itself indefinitely, however Cycles only counts to 10 refines and then stops, creating a render which is a pixel-perfect match of the ordinary rendering method when it's completed.  I understand that there are tricks that can be used to reduce noise, but at the cost of extra processing time and usually small quality conflicts, like blurring.  My question essentially boils down to is this Cycles' current limit? Turn off display in Windows on command I was able to post in chat with less than 20 rep by joining 20 sites I joined 20 other sites (out of the many) and even with 1 rep was able to post in any of the chatrooms. For example: In ELL, I have just 1 rep and have posted messages in its chat.  ell.stackexchange.com/users/18923/lamart This seems like a bug because I should have needed 20 rep to post. . EDIT: From , I got the idea to make this edit. To reproduce this bug/error:  Create a new SE account. Use it to make an account here. You will get 1 default rep. Choose a random SE site and use this account to get 1 rep on that random site. Repeat the above step 20 times. Now you have 1 rep on 20 network sites but the net SE rep is 20. Go to the ELL chat and ping me. (important step)  From my comment: I have now got 40 rep since people voted this question up. Initially I had net 20 rep gained by creating 20 accounts on 20 different SE sites. Those default 1rep added up to get me to 20rep and I was able to chat. The link says one needs 20 rep in any of the SE site to chat in &quot;all the other&quot; category chatrooms..... but I did not have 20 rep on ELL at that moment.