Wavy-Scope | Handheld Signal Finder to Detect the Sun, the Moon and Even Satellites in Space Using Radio Signals | Portable Handheld Radio Telescope
by bhuvanmakes in Workshop > Science
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Wavy-Scope | Handheld Signal Finder to Detect the Sun, the Moon and Even Satellites in Space Using Radio Signals | Portable Handheld Radio Telescope
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Project Objective : Accessible and Fun Radio Astronomy Science
Space is full of mysteries, humans have looked up the night sky for thousands of years dreaming about these mysteries, however we humans of 21st Century look up the night sky very differently from our ancestors, we use modern equipment to understand the vast wonders of Space, this includes Optical Telescopes, Radio Telescopes, Satellites, Gravitational wave detectors, etc.
However, most of these devices are rather sophisticated, expensive and require well calibrated efforts for detection. Even hobbyist equipment such as Optical Telescopes need good mounting systems for reliable observation.
Hence the objective of this project was to design a new form of Space exploration and detection, especially for kids, young adults and everyone else who feels a sense of awe and wonder when they lookup the void of Space !
I am starting WavyScope as an Open Source project with all the 3d model files available for everyone to download, make this project, share your feedback and please add on to the designs for even better versions of the project.
I have designed WavyScope to be portable, sci-fi looking and also super functional. This device is basically a signal strength meter made using off the shelf components and Radio Astronomy principles, capable of detecting radio signals emitted from the Sun, artificial satellites and even signals reflected off the Moon ! This data is displayed on the Signal Finder and can also be measured and study using of the shelf electronics for interesting Amateur Radio Astronomy applications.
Supplies





This project uses the following components.
- A Single Channel LNB
- dB Meter or Signal Strength Finder by SOLID
- 1 meter, RG6 Coaxial Cable
- 4x RG6 Male Connector adapter
- 4x 18650 Li-Ion Cells
- 2x 2 18650 Cells Holder
- 1x 18650 Li-Ion Charger
- 3D printed subcomponents
- A microcontroller ( Optional for data reading, logging and processing )
The LNB and How It Works


Before understanding how the Wavy Scope, let's understand a little about it's components, starting off with the LNB or the Low Noise Block Downconverter.
The LNB ( Low Noise Block Downconverter )
The LNB is used in TV Dish antennas as TV Satellites transmit in the Ku-band with frequencies ranging from 10.7 Ghz to 12.75 Ghz which is typically referred as the microwave region.
The LNB is meant to detect this signal, amplify it, mix it with an internal oscillator and then down convert the signals to a lower frequency band, typically the L-band ( 950 Mhz-2150 Mhz ) This down converted signal is then received by the set-top box. If you want to delve deeper into how an LNB works, I have attached a relevant article here : https://en.wikipedia.org/wiki/Low-noise_block_downconverter.
How is the LNB useful for our requirements ?
Since the LNB is capable of detecting microwaves in the 10-12 Ghz range we can use it for detecting signals from Space ! From the Sun, the Moon, Artificial satellites and essentially everything else that emits signals in the 10-12 Ghz frequency range.
References to Diagrams used :
Figure 1, Working Diagram of a LNB : https://dreamcatcher.tynet.eu/t/lnb-circuit-schematic/6280
Figure 2, Circuit of a LNB : https://www.qsl.net/zs6bte/Ku%20band%20LNA%20optimisation%20to%203cm%20band.html
Objects and Their Frequency Emission Range


Above is a graph of Frequency vs Flux of different stellar objects, if you observe the diagram, the emissions from the Sun, the Moon and multiple stellar objects lie in the detection range of our LNB device.
This makes is feasible to detect these objects using a LNB, however for detecting more fainter sources we need to introduce better reflector sources in order to increase the sensitivity of our detector, hence for this project we will try to focus our detections on the Sun, the Moon and some artificial satellites, but hey ! that does not mean you need to stop with these three, you can try pointing your WavyScope towards any object of your interest to find if the device will start buzzing, remember, Sky is the Limit !
Our Detector : Satellite Finder DB Meter


Now that we know the LNB works and how it is capable of detecting signal emissions from different stellar objects, we next need a device to actually measure these signals, for this purpose we can use standard SDRs or Software Defined Radios as the down converted signal from our LNB will be interfaceable with a standard RTL-SDR dongle using certain pre-filters.
However, the objective of this particular instructable is to design a portable, no-code and easy to make and use signal finder, hence instead of using expensive and scientific equipment we will repurpose a Satellite Finder as our detector.
These Satellite Finders are typically used with LNB's to align the TV Dish Antenna's with TV Satellites staged in geo-stationary orbit, these usually have an analog meter and a buzzer which varies it's intensity based on the detected signal strength.
I have sourced the following Signal Finder ( https://www.solid.sale/db-meters/solid-sf-45-meter ) as it is widely available, however you can source any signal finder of your liking as these are directly compatible with the LNB's, just check of the band for which your signal finder is meant to be used. I have chosen the LNB as well as Signal finder meant for Ku-Band.
Design Sketch

The key idea behind this project was to make a portable or preferably handheld Radio astronomy solution meant to encourage kids and enthusiasts to have fun while doing science.
This idea has been the key principle while designing the WavyScope, hence I have tried to give it a retro sci-fi design vibe while keeping the Co-ax cables visible to make these a part of the entire design, also since Co-ax cables are tricky to wind-up, I have considered to allow their natural curves to be a part of the design.
Powering Up the Device
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Typically LNB's and their Satellite dB meters are meant to be powered by the Set-Top box connected to them, however this makes the WavyScope impractical to carry around and hence forces it to loose it's portability and hand-held formfactor.
Hence I am powering the Satellite meter and the LNB using a >12V battery pack, to be precise, in our case around ~14.8 V. I have attached 4x 18650 Li-Ion cells in series to form this battery pack.
The Satellite Finder and the LNB can be powered by any source between 12V to 18V, however the input voltage determines it's fluctuations over detection intensity, but in our case we do not need to consider those changes.
To power up the Satellite finder, I have stripped off the Coaxial Cable at other end and separated the copper core and the shielding. We will power the Copper core with +14.8V and the Shielding end with -14.8V
Enclosure Design




I have designed the enclosure for WavyScope on Fusion 360, you can use any design software of your liking, Since this design requires some lofting components I find using Fusion 360 the most suitable.
I have designed the WavyScope such that it needs minimal support structures while 3d printing, the design of the WavyScope is however going through refinement and I will keep updating with design and function improvements.
You can find the design files for WavyScope V1. Attached here
3D Printing the WavyScope

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I have 3D printed the design components of WaveScope using FDM printing in PLA filament as it suits our requirements, you can use any printer or slicing software of your choice for this purpose, I have 3d printed the WavyScope on Bambu Lab A1 and the files have been sliced using Bambu Slicer. I have attached my printer profile 3MF File for easy of printing to you guys, you can use it directly if using Bambu Lab slicer.
Downloads
Assembly







(Optional) Analog Read Values From Db Meter
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Further I am working on interfacing data from the Signal finder on to a microcontroller by attaching the signal readings from the Satellite Finder dB meter to the Analog read pins. This results into a much detailed plot of time vs signal intensity usable for more advanced measurements.
Test 1 : Sol (Detected !)



I started with testing the WavyScope to detect the largest source of Radio Waves in the Solar System, the Sun, and the results were really good as were expected. You can find the testing Video here :
Test 2 : the Moon (Detected !)



Since the Moon reflects of light from the Sun it should be easily detectable against the background of night sky.
However, it becomes especially difficult to detect the Moon on a bright morning because the intense strength of Sun's solar radiation overpowers the reflected waves from the Moon, hence I expected that the device wont work at all, however I was pleasantly surprised when I was able to detect a spike in detection around the alt-az coordinates of the Moon. Here is the detection video of radio signals bouncing of the surface of the Moon using WavyScope.
Test 3 : Satellites & More (Faint Detection !)

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The next object of interest was Geostationary Satellites, although the WavyScope was able to discern patches of the night sky, the detection was still a little weak and lacked the expected clarity. However since the detection system is analogue in nature it was pretty easy to tweak the sensitivity of the WavyScope to detect presence of artificial satellites, this seemed the most amusing part of the project as these satellites were detected by the WavyScope even though they were not visible by the naked eye.
As a plus, the WavyScope is not limited to stellar objects, it detects most high frequency emitting objects, including computers, microwaves and maybe while playing with it you might detect something much more interesting !