Initiation: Machine-controlled Radio Scope

Hawai'i! Go over earlier anything else my website to find other unagitated overgorge: https://xval.me

Late I have had many free hours to dedicate to projects and there was one that I really wanted to make: an transmitting aerial to discover the vast Universe. But not a traditional one, that DIY residential district uses. I wanted something different, that could be more hum... "professional". Basically, an automatic radio antenna, that I rump control using a computer, to automatize the data gathering. Now, I conscionable have to rest mellow, spell this kinetic antenna on my roof is assembling everything for me, always. Fantastic!

Step 1: Primary Objective lens

I build it with one objective in judgment, just I besides ill-used it to other things. The originative purport was to build a saddle horn that could receive signals from the H Line from our wandflower, to calculate its speed, just it buns also be used to receive signals from geostationary satellites that transmit in well-know frequencies, with a non-encrypted signal.

Footmark 2: Just about Warnings Before Moving On

First things first. Side is not my mother tongue so some mistakes here and thither may come about. It is as wel a flake hard to find the English name of many tools, so correct ME if I am wrong. Thanks!

On this instructable I am not going to describe everything, piece aside piece. I am going to talk about the main things, what I consume done, but I volition also consider that the reader has an reason on what I´m talking about. Like, for example, the arduino codes are so trivial and loose to do that I will non place them here. However, I am active to line, of course, they working principle. I want this instructable like "Look what I´ve done", openhanded to the proofreader knowledge if one wants to physical body something like this and non a unmitigated step by step guide, screening every last the details. This is like a dispute to everyone who is reading.

Step 3: What I Gestate From the Reader

You don´t need any noesis to read my project on the William Claude Dukenfield I am going to talk, merely if you want to progress something similar this, you really deman standard understanding on these topics. At the end of the day, to build this externalize, I had to use up many skills. I am talking about:

-Programing experience in Arduino (Well, everyone potty program it. After all, is very simple)

-Software package Formed Radio or SDR (Basically, there are dongles that allow us to follow vast areas of the electromagnetic spectrum on our computer, and they are cheap! For instance, the RTL-SDR V3 dongle, let us to watch from a few KiloHertz to around 1,8Ghz. They are receivers that we can tun the frequency we want via software. I assume the lector knows the basic of this)

-Wildebeest Wireless knowledge (For those who don´t know, GNU Radio is an gaping-source computer program that works with "blocks" and from each one blocks has a function. This is extremely expedient to automate data gather and to calibrate the instruments. If you require something simple, like "OMG! I could see the Hydrogen air!" you can purpose simple software like Airspy. But if you want something deeper you mustiness use GNU Radio. Like every open source program the best reward is your biggest foe. You moldiness know what you are doing. There many docs on the web explaining about it, but do not have a bun in the oven to have everything waiting just for you. You will have to do a LOT of research. However, I will place the image of the diagram I made here on the instructable to work as a citation to you.)

-Programming experience on Linux (This is mainly for Wildebeest Radio, since you have to write cipher connecting GNU Radio and Arduino control of motors)

-Feel for working with Aluminum cross. I am talking about bending, cutting and that kindhearted of stuff

-Electronics in general to wor problems with the motors

-Basic astronomy understanding for positioning and coordinates

-Physics in overall, if you are sledding to observe the Hydrogen Line

Step 4: Safety First

Don´t be a fool and hurt your self. I used as the construction material in this project aluminum foil and IT can really hurt you if you Don River´t use it cautiously. Before nerve-wracking something like this, take a leak true you can handle it and be disposed. I Don River´t commend anyone to start using aluminium foil like in a project like this. Wear´t dress that. Power train yourself first and so apply it. I father´t even have to talk well-nig wearing gloves, etc etc. Again, I assume the reader has some liberty with those things I mentioned in front.

Step 5: Lets Start

So...Time to head start explaining how it works. To do that we deliver to understand what are the different parts of this project. I will talk by and large about Atomic number 1 Line since I am more focused thereon take off. The atom of H randomly radiates at the frequency of or so 1420,4 Mhz. This is due to a tailspin flip on the Hydrogen atom (At that place are tons of utile selective information nearly this along the internet, so I will only get across the basics).The radiation sickness comes from the hydrogen's transition between two levels in its ground State, specifically named the 'spin-flip transition'. The hydrogen's proton and electron each let their ain spin, and they toilet either spin twin operating room antiparallel to each other. The put forward with line of latitude spins is slimly higher in energy, indeed when the spins flip, it releases energy as radiation that we lav detect. Merely this is rare. the chance of this to happen is real small. However, along stars, there are scores of hydrogen atoms (Hydrogen is the most superabundant element on the intact World). Because of this, for us, we will ever see a ear on this frequency when observing with SDR, since there wish be always at least one atom flipping and emitting frequency. Sometimes this is known as 21 cm band since in the vacuum the wavelength of this frequency is of almost 1420,4 Mhz. Since the Milk Right smart is made of tons of stars, and, for us, they are relative collectively, the signal is stronger. You can too period the horn to the sun merely it won´t influence, since the Sunlight is hot and the frequency will be different. Since the Milk Way is light years far from US, we can still receive the cold bespeak since it traveled all around the space. This signalize is actually pretty shoddy, and we need an aerial.

Footstep 6: Transmitting aerial

Soh, the first part of the project was making an transmitting aerial to ameliorate the signal. I could have used a representative satellite ravisher, and information technology would probably work, but I used the intention from DSPIRA (Google information technology if you want the sizes and how to do it etc) that was successful just for this case. I ready-made a VERY sagittate image in paint to evince you its work. I changed a few things (just the size) and the result was a very interesting horn successful of aluminum foil (I used the token heaviness I had at home then the weight is fine simply information technology does not really matter). Just we are not done yet. This trump will catch all the frequencies on the spectrum, but we only want some. For that, we bear to add at the back of the French horn an wave guide that will allow United States to catch our desired signal and block the frequencies we don´t wish. Usually, enthusiasts use F style picture cans, that have a size of around 1 gallon. They are ready-made of aluminum (that is what we want) and the the right way dimensions to block most undesired frequencies and pass what we want. These numbers game are from my steer, so before credulous me, research a bit, but most cans will pass, without lowering the mogul of the desired signal, the frequencies from 1,1Ghz to around 1,9Ghz if I am correct. This is extremely important because will block the frequencies of some 100Mhz, the most victimized ones, that could have a nonindulgent touch on our signal. So, if you are on a budget, you commode use an old painting can, cut it on the front, and tie in it to the horn. I ended building my ain waveguide in aluminum foil since information technology was easier to connect to the horn and to be perfect, since I did nto have to hack the front part- I just did not make IT. From the left English to the right one, that connects with the wave guide (the side without a "wall") I measured it and the outcome had 17,2 cm. To reckon the cut-off absolute frequency (the frequency where the signal will be drastically reduced) you can employ the formula, that is pretty simple, or use an online calculator. Just google for Waveguide edit off frequency calculator. The cut forth frequency in my case is around 871Mhz and the wave guide testament alow to expire, almost without fading the frequencies from 1Ghz to 1,65Ghz. Faultless.

Step 7: Copper!

Now that we have our wave guide we have to rate a small piece of cooper into information technology. To manage that I made a hole on the top of the inning of information technology properly in the midst. The distance from the back break u of the wave guide and the cooper should be 6,5 cm and, since we want just to collect the frequencies of around 1,42Ghz, the Peter Cooper distance inside should be of 5.25 (one and only quarter of the desired wavelength). Make sure the cooper suffice non touch the tin foil, since it works and ground and you won´t get any data. To do that just use some magnetic tape.

Dance step 8: Amplifying Our Signal

Swell, I used around software now in this part to calculate how much is the gain of our trumpet. Accordant to my computer information technology is about 14-17dB, a respect that seems pretty good for a home-cured aerial. But this is not enough. We need to a greater extent gain to increase the power of bespeak. Course, we are going also use increase the noise that exists, because nothing is down, just the signal/noise ratio will be bigger when amplifying the signal. It would make up interesting to introduce here the conception of resound figure of speech and noise temperature. The noise figure is the difference in dB 'tween the noise production of the real receiver to the resound output of an "perfect" recipient. So, basically, the difference 'tween our noise ground, or the reference, and the indicate we desire. Since the 1420,4Mhz frequency was emitted far far aside, the signal will be weak and the interference figure besides volition be frail. So, we need to find the point altogether that noise. And here is where noise temperature comes in, that is basically the cookie-cutter thing, merely we also use the temperature. You tin can use this estimator present to calculate it. I will not beryllium going into details since everything is freely available in the internet. Astronomers mostly use these units, so get accustomed it. The reference temperature we use when doing the maths is nothing more that the temperature of the system that is going to collect the signal, in this display case the temperature of the environment, in Kelvin. I consider it 300K, that is a pretty reasonable number. So, according to galore early people World Health Organization too received this impressive, we are expecting the posture of the signal to be of approximately 100K to 150K. Information technology is a pretty humbled number, so we need to be careful when amplifying information technology to non increase excessively untold the another noise we don´t want. To do that, I fashioned a racing circuit and ready-made a PCB.

Step 9: Circuit

To gain the gain of our organization we wont what is called LNA or Unrefined noise amplifiers. These amplifiers have a scummy noise factor, and so they introduce virtually no stochasticity in the system, and increase the in demand signal. When exploratory for an LNA, you essential represent careful with this, since you wear´t want a noise factor that is as well big, since it will add noise to the scheme. An "okay" LNA has a noise factor of roughly 1dB and the best ones have around 0,6 or even 0,56. You can think that they are really expensive and if you are going to corrupt the best ones online, yes, they are. The general ones give around 1,3dB (this is the grievous bodily harm noise factor I would choose if I were truly on a budget) and are really cheap. You hindquarters buy them on amazon for some 15$. The best ones can go up until around 50 our 60$. BUT, here is where things set about to be exciting. You hindquarters build your possess LNA. If you take over experience with PCB excogitation, it is not that hard. I talk from experience since I built my personal board. The chips you need are easily on hand, are chip and...have a resound factor in of 0,56dB! Impressive. But, before going into dept on what chips to choose, there is something important here to talk nearly. We have got the horn, that gives USA approximately 14-17dB of gain, we have the LNA, that provides almost 35dB but there are parts missing. Later on accelerando the signal, we need to use a filter to only allow the frequencies we want to pass. We already filtered more or less frequencies, just we should filter them once again, right away in a smaller range. To do that I used a pass band filter chip, that I am going away to describe together with the LNA. The last stage of our circuit is basically another LNA, the Saami fashion mode, to increase flat more the signal. After this, we connect our circuit to the SDR dongle, in my case the SDR-RTL V3, to observe the impressive that, now, stern be watched.

Step 10: Chips and PCB

So, the signalize has to follow this path:

Cosmos>>Horn>>Wave Guide>>First LNA>>BandPass Filtrate>>Second LNA>>RTL-SDR

The LNAs I used and the bandpass filter are from Miniskirt-Circuits. They accept a program named EzSamples and, if you are doing a research project or want to test something, but don´t privation to pay huge prices from resellers, you posterior go at once to their website and ask from samples. The components that are marked with the Ez logo you can request, and they are free. Every 30 years, you can ask a max of 5 varied components, and they testament send to your home (usually takes 2 weeks) 4 samples of for each one factor. On the image is the packet I standard from Mini-Circuits with whol those delightful chips. So, for the LNA that would cost around 50-60$, I ended paying only the PCB, since the chips were on the loose. The part number of the LNA is the PMA2-43LN+. Its a SMD chip, with almost 35dB of gain and a first-rate low noise figure (0,56), openhanded a noise temperature of about 41K. Since the impressive has a strength of about 100-150K, this number is perfect for our of necessity. On my 4 level PCB (you Essential employ a 4 layer PCB to reduce the signal losses and interference) this was the first thing I added. You can´t only expend the chip, since IT needs many auxiliary components (some inductors, capacitors and resistances). But preceptor´t worry. Mini-circuits made the work for you and you have along the main varlet of the component all the values and schematics you testament need. You don´t have to be a electric engineer to make indefinite of those. After this LNA, I added the band take place filter, a BFCN-1445+, also from Mini-Circuits and I successful all the design again for the second LNA. I should add that the noise factor of the second LNA does not really matter. You toilet use one with a Large noise factor and the difference would be like minimal. Like, for instance, the noise factor of the RTL-SDR uncomparable is around 6dB (according to the specs is less, but I ne'er trust what they say), merely, since it is the 4th amplifier (the amplifiers are the horn, 1st and 2nd LNA and the dongle itself) no problem at all. The boilersuit noise factor can be calculated victimisation Friis rul for noise, proving what I just have said. At the last of the day, I payed 45$ for the PCBs what I can say I am very slaked. Since they were 5, I saved here tons of money. If I had bought everything, I would have payed around (50*2 for the LNAs and around 40 for the filter) roughly 150$. With all my work, I made 5 PCBs, that Charles Frederick Worth, if bough, 700$. I think it was a good investment of metre and money. If you want to brawl a project like this one and want the PCB layout, sorry well-nig that, but I testament not place them here. I had to work hard many hours just in research, and other TON of hours to build schematics, and PCB, and soldering everything. If you are really interested, send Maine a message and discourse your goals. If I catch it worth it, I will give the layouts to you.

To get in touch the output of the amplified signal to the RTL-SDR I used sweet-talk cable that is used in superiority boats, with a big good tone, to avoid losings. At the end of the day, the board amplifies the signal by 70dB, accordant to the manufacturer of the LNA´s chips. The signal was actually amplified by 60dB, which seems pretty good.

The tot gain before the SDR dongle is astir 75dB. An impressive number!

Step 11: GNU Radio receiver

Since I wanted to receive the hydrogen line, I used GNU Radio to automate all the mathematics and stuff for ME. In the image I have the diagram I used. Fundamentally, the betoken enters, IT is calculated the Fourier Transubstantiate, calculating the add up of energy I received in all oftenness. To make out that, I divided the waveband into small "bins", where is calculated the amount of energy received in a particular proposition time. I won´t equal in inside information, since this is complicated stuff, but, if you understand GNU-Radio, you can understand what I am doing with much details. With the "bins", I can then calculate the speed of the galaxy, e.g., using the red shift.This is named power spectral concentration, which is the power per unit frequency, given atomic number 3 a function of the frequency. My goal on GNU Radio was to make a spectrometer that could act this in frequencies of about 1420Mhz. The deep part of the receiver is calibration and adjunct systems, to support the core of the liquidator. If you are having problems with GNU Radio, comment, indeed we can wholly larn together while solving problems. Sorry about he image, but I could not get any better one, when trying to print my sort.

Step out 12: Supporting the Horn

Since I decided to use tin foil Eastern Samoa the building material for this project, I made completely the supports and bases made of aluminum as well. As you can see, I build 2 supports, one in one side of the cornet. I later built 2 dwarfish pieces on the top side of the horn soh I could pass a cable trough them to keep going it. To do that I found the center of mass of the motor horn, to make sure the system is balanced when not existence used.

Step 13: Supporting the Automobile horn

The 2 supports one the side are set on a base that is made of aluminum foil. At the beginning I though the thickness of the base would cost adequate for all the weight down but I realized that I requisite IT to be even stronger. To make it better, I added a large aluminium foil, with a larger thickness, on the bottom, to support it. I can´t empathise why, but Instructables website always commute the rotation of the last photo. I could not put it right. Sad-

Footmark 14: Rotation Arrangement

Now, lets utter active how is the organization going to rotate. We need an xy axis rotation system, and a z axis rotation system. This last one takes care of the angle of the notice and the other of the counselling that the horn if facing. The xy was mounted on a Grant Wood weapons platform, from an mature set back, to indorse, and a motor makes information technology spin, spinning the platform that have the supports of the French horn. On the top of the bottom of the support for the horn there is another motor that controls the lean.They both are controlled away an arduino and motor shields to control them.

Step 15: XY Axis

Since the automobile horn + the supports to the horn + the base of the supports have a lifesize weigh, a normal DC motorial would non take care of the job to circumvolve this. To solve this problem, I dismounted an nonagenarian hand boring machine, that uses a 12V bombardment. And another problem appeared. I was planning of exploitation a L298N motor device driver to control the efferent from the arduino, but I ended blowing up the 2 I had at home because of the current. The scoop current they can handle is 2 Amp and a oil production machine can eat up to 5 Amp. I had forgot about this completely and it took me hours to interpret the trouble. When I figured out, I had lost 2 drivers. To solve this problem I made an H-Bridge with 2 relays, that let me to change the polarity of the current and then to change the spinning direction of the motor. There is an pictur explaining how it works. Since 12V would spin the motor besides fast, I decided to expend a 9V power source that could handle 5 Amp, so...forget almost the typical chargers you take in at home. The motor is and so socially connected to "that red matter". Don´t ask Maine its name because I don´t know. If anyone could give me the distinguish of "that thing" I would really appreciate. Information technology basically changes the direction that the causative is spinning too, in that case, 90 degrees. Words are adamantine to explain it, with the image you will contract it easily. I had to fix it to the put of and so unite it to the motor.

Ill-use 16: Fixing the Motor

Since a lot of tensity is on the motor, I had to desex it to the table.I also had to change the came of the efferent, to connect it to the "red thing".

Step 17: Any Testing along the Motive

Stride 18: Wheels

Since "that red thing" is very small, all the weigh from the top is beingness "canalized" to IT, forcing symmetric more the motorial. To spread the weigh I added 4 teeny wheels along the corners of the meanspirited, that have a inferior leaning, so they can rotate in a circle. Now, the system is much stable and, alternatively of only one support, I have now 5.

Footprint 19: How It Looks Like

Step 20: Z Axis

Now the Z axis, OR the inclination. To spread ou the horn added a stepper drive that pushes a sportfishing logical argument that is connected to the horn, changing its angle. You can see that in my awing Piece of Art paint image. The put together in the prototype is the normal cardinal, with the center of mass aligned. If I want to increase the weight, I turn on the motorial, that starts spinning, pushing the sportfishing line, represented by blue colorize. It starts becoming shorter, creating tensity and then rotation the horn. The maximum angle I privy get over is around 80 degrees, which is pretty good to analyze a crowing part of the Cosmos.

Stair 21: See to it

As I mentioned before, I am not going to write here the arduino code but I will explicate to you how the system works. Basically, I created a procedure with 2 variables that I input: the direction angle and the rotation slant. The first one is the tip that I want to spin in the xy axis and the other one is the right ascending tip over. The xy axis is the just about tricksy because we assume´t have an exact way to point to unrivaled direction. I could have used a compass chip, but it would give me worry just to configure information technology to, since the north celestial pole is non the magnetic northernmost pole, and I would be a mess. I ended up using a gyroscope module that came with an acceleration measure. With that, I can measure the acceleration and, with the meter that it is rotating with that speedup, I can calculate the angle that information technology rotated, until reaching the desired Angle. There are many tutorials happening the net about that. Of course, thither is an erroneous belief margin, caused by randomness. Even when the system is stopped, the quickening meter leave say that there is acceleration. Just, since IT only moves small distances, there is nobelium problem with the noise created, because every time it needs to rotate, its made a reset. The Z axis is simplest united. Since I have the gyro integrated on the same plug-in with the acceleration meter, its 2 in 1. The gyroscope essentially tells me the lean against it is in the 3 dimensions. In this showcase I solely penury 1, the Z axis. When I ask my telescope to change its angle, it starts the stepper efferent, ambitious the fishing line. The angle will slowly start increasing and, when it reaches the desired angle, information technology stops spinning. IT is earthshaking to mention that the motor is stepper, so, when I wrick it off, it won´t rotate backwards because of the weight of the horn. It moldiness exist in tension and being a stepper it can maintain it.

Step 22: Tasty Dreams Are Made of This

Well, now the system of rules, in terms of hardware, is primed. Now, I can act up what I want with information technology. The main goal was to gather information to be unnatural after during the night, in an automated means. But on that point is something wanting here. The connexion between the arduino and the GNU Radio. To do that, I created a bare Python file that controls some things. It launches the arduino code with the angles, that are given by information technology, and then launches the GNU Wireles, gathering the data and storing it on a pamphlet with entirely the information for a given tip over. I wrote it to to being spinning during the night for totally the angles possible, giving a allowance of 5 degrees. Like, at the XY bloc it spins 5 degrees each time, in a total of 72 times. The Z axis is the same, from 0 to 80 degrees, witch gives 20 times. for each time on the XY axis it repeats 20 Z axis vertebra angles, writing a ton of information. At the cease of the Day, it takes close to hours to compile the information from all the practicable angles. I am currently functioning on this information, trying to analyze it, and then I am non going to talking about that part on this instructable. This is only about gathering data.

Maltreat 23: Finishing

So...this is what it looks! A M A Z I N G

If you are reading this part I know that you enjoyed this report roughly my project. Comment something! See you adjacent time!

Atomic number 4 the First to Portion

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