My personal recommendations, thanks. Authored by Ian C. Check out the Amazon Electronic Component Packs page. A RF Spectrum Analyzer is a very special kind of superhetrodyne receiver which receives a chosen range of signals and displays the relative signal strength on a logarithmic display, usually a cathode ray oscilloscope - CRO.
The first thing I sincerely recommend you do is buy this excellent reference book through my amazon affliate program. Paperback and published by ARRL - delivery 3 to 5 weeks.
Why do I personally highly recommend this book? Wes Hayward is the sharpest designer I know and is highly respected as the "guru" and I don't make strong recommendations lightly.
At the low price it is literally among the cheapest investments you will ever make in your electronics education - believe me, even if you are not especially interested in radio frequency design you will learn a lot of basic principles which are universal in electronics.
And you will write and thank me for doing us both a favour. This Spectrum Analyzer project is available as a relatively inexpensive kit and is highly recommended as probably the best piece of test equipment you will ever own. Professional Spectrum Analyzers usually cost tens of thousand of dollars and for good reason. Thanks to the skills of Wes Hayward and Terry White, this Spectrum Analyzer project costs a mere fraction of those prices and sacrifices very little in performance.
As I said earlier a Spectrum Analyzer is simply a specialised superhetrodyne receiver which usually employs a multiple mixing scheme to achieve reception of the higher frequency signals.
This Spectrum Analyzer project has an upper frequency limit of 70 Mhz although this can be extended by usng converters. It is a double conversion scheme. The general idea is to slowly sweep through a range of desired signals, all the while converting them to a much lower frequency where they are individually within practical limits converted to a DC level representing a logarithmic or decibel level for display on the cathode ray oscilloscope - CRO.
Here meaningful comparisons and information about the signals can be discerned. Indeed a Spectrum Analyzer is a very poweful piece of test equipment. The first IF is set at Mhz, the swept first oscillator, - Mhz, utilises a commercial voltage controlled oscillator. The second IF is fixed at 10 Mhz. Quoting in part from Wes Hayward's and Terry White's article:. The display shows the strength of all signals within a user-defined frequency span.
Each signal is represented by a line or blip that rises out of a background noise, much like the action of an S meter. Commercial analyzers are calibrated for signal power, with all signals referred to a reference level at the top of the screen. Our analyzer is designed for a basic reference level of —30 dBm, a common value in commercial analyzers.Remember the Girl Tech IM-me? It was a hot-pink clearance rack toy that suddenly became one of the hottest commodities in the hacking world when it was discovered they could be used for all sorts of radio frequency shenanigans.
Now they go for triple digits on eBay, if you can even find one. Thanks to the work of a hacker named [ea]this cheap educational gadget is finally starting to live up to the potential we saw in it back when a teardown revealed it was powered by an Arduino-compatible ATmegaRF chip.
But the prices went through the roof when we first posted about itso get them cheap while you still can. Even using one up to show the real-time status of your build or system resource utilization would be pushing it at this point. To get our attention, your traffic light is going to need to have a unique hook. So how did [Ronald Diaz] manage to get his project to stand out from the rest?
Working from a video of the traffic light on YouTube, [Ronald] was able to extract and isolate the tones he was after. Performing spectral analysis on the audio sample, he was able to figure out the frequency and durations of the eleven individual tones which make up the complete pattern. The Arduino Pro Mini used to control the traffic light is not only responsible for playing the tones through a piezo speaker, but as you might expect, for firing off the relays which ultimately control the red and green lamps.
With everything carefully orchestrated, [Ronald] can now get that authentic Australian side-of-the-road experience without having to leave the comfort of his own home. This traffic light that tells you how the value of Bitcoin is trending is a great example. Or maybe this one that can tell you if the Internet is down. Do you have an EMC probe in your toolkit?
Usually such probes are used in anechoic chambers and connected to sophisticated gear like spectrum analyzers — expensive stuff. But there are ways to probe the electromagnetic mysteries of your projects on the cheap, as this DIY EMC testing setup proves.
It used to be a spectrum analyzer was an exotic piece of gear. However, these days it is pretty common for a scope to have some ability to do the job — that is, plot amplitude versus frequency. However, a dedicated commercial product will usually have a lot more bandwidth and other features. It needed power, but it was also missing the internal flash card that the device uses to boot.
However, many tiny screws later, you can finally see the actual electronics. And it looks like it could be incredibly handy. Normally, non-contact tachometers are optically coupled, using photoreceptors to measure light flashing off of a shaft or a tool. But that requires a clear view of the machine, often putting hands far too close to the danger zone.Welcome, Guest. Please login or register. Did you miss your activation email? This topic This board Entire forum Google Bing.
Print Search. Is this the right ingredients for making Spectrum Analyzer? One jar of sweat and tear's Anything i miss? Anybody have try this before, suggestion, and critique is appreciated and because it's EEVblog Receipe for disaster. NZ Siglent Distributor. The simplist approach would be a sdr stick. Quote from: tautech on April 18,pm. Quote from: dannyf on April 18,pm. I am about to build one, I'm going to use a double mixer approach, mine is only a low frequency one though, I will use a vco with a Mhz range then down convert it with a mixer with a fixed oscillator of Mhz to give me a Mhz output that I will mix with the Rf, then I will pass the If through an If filter, envelope detector then log amp, but I may do the log amp in software if its possible.
Software defined radio. The cheap ones go for like ten usd. Quote from: electronics man on April 18,pm. The software is a bit fiddly, but once everything is installed, it works great.
Of course, your results depend on how good your antenna is. Fraser Super Contributor Posts: Country:. The first true spectrum analyser that I built was a kit from Electronics Australia in I still have it and it still work well.
This was tuned across an area of the band using a ramp signal on the VCO input pin. The output from the tuner was around 47MHz.
The swept VCO ramp voltage and detector output was fed to an osciloscope X and Y inputs after appropriate processing. The unit was great fun to build and worked very well indeed. It contains a discrete component RF front end, in the form of the tuner, and this could be changed to other tuner types with different capabilities.This section will list several projects which will allow you to build your own RF design test equipment.
Microwave construction techniques and basic electronic skills will be required on some projects, but the tools you can make will equal what the so-called "professionals" use.
We modified the iwconfig command included with Jean Tourrilhes' Wireless Tools for Linux slightly to help with the wireless link setup and alignment. Here is what the original output of the command iwconfig eth1 would look like:. Here is a screen shot of the modified version. It displays the same information, just with some lame ANSI colors and a bar graph for signal strength. I'm not sure if it's entirely accurate, so use at your own risk.
You can pick this version up here. It also includes the perl script pinger. It's just a wrapper around the ping command to display the millisecond output with an ANSI bar graph. It also has an option for using the 'say' command from the rsynth package to speak the ping millisecond value to you. That's useful for when you're hanging from a tower trying to align antennas.
Another method of testing the received signal strength on a Symphony based wireless network is with a homebrew signal meter. RSSI stands for relative signal strength indicator and supplies a voltage output that is an indication of the received signal strength.
On a weakly received signal the voltage output of the RSSI is small and on a strong signal it's large. Unfortunately, this output is only on during the receive portion and off during transmit. This makes the RSSI output look like a series of spikes.
To average out these spikes you can use a very common piece of test equipment on any good technician's bench: a modulation meter. You say? Modulation meters convert received audio signals into a DC voltage indication of modulation, if you input the RSSI spikes into the meter and readjust its ballistics you will get a poor man's signal meter.
The meter I use is based on the Mark Weiss modulation meter. This is a simple field strength meter that can be used to verify that you antenna is in fact radiating energy. You can also make some attenuator pads to help simulate real life signal loss when testing your wireless network links. You may also combine attenuator pads to increase the overall attenuation. It's also possible to use a long length of high-loss cable, such as RG, as an attenuator.
Higher wattage resistors will handle higher RF power, though the frequency response will suffer due to parasitic reactances. Lower wattage resistors will handle higher power if applied in small durations millisecondslike which is commonly found in most wireless network applications.
Here is a schematic for a homebrew cable reflection tester from the December issue of Electronics Now. It's very useful for checking coax cable runs for shorts or even impedance mismatches.
It works by sending a pulse down the cable, then checking the return signal on an oscilloscope. Be sure to divide your time by 2, and take in account your cable's velocity factor.
Here is a device called a 2. One of the coolest things to do is 2. They transmit about 1 mW on the frequencies of 2.
They can even be modified for an external antenna output jack, just like the Symphony, and can also have their output RF power increased to around 60 mW. Refer to this site for a how-to and schematic for that modification. It's not an entirelly accurate analysis do to the narrow bandwidth of audio, but should still be useful.
It is capable of detecting signals as low as dBm. When combined with 2.April 18, by rlaude. Below shows the still not enclosed receiver below:. These will be used near the VFO and the 2nd IF coils, but not so close as to pull the frequency too much. The initial tests picking up the VFO oscillations showed a rather limited effect as witnessed by the frequency counter readings. The DIY probes are shown below.
Pretty simple builds using bits and pieces from the bins:. SW 2nd Mixer coil low end SW 2nd Mixer coil high end The results indicate descent correlation between methods used for the experiments attempted. April 14, by rlaude. But my attention wondered a bit when I ran across a post concerning a Python-based spectrum analyzer PyDSA which uses a Rigol DSO as a digitizing front end which feeds a data acquisition software based system.
The program code was originally written for use with a Rigol DS model but revisited in order to accommodate a DSZ scopes programming requirements. My familiarity with Python was pretty much zero and still is when I began to setup the python environment on my Win7 x64 machine.
Fortunately the process was straight forward enough to get things going after a little on-line reading. But, there was definitely some glitches along the way. PyVisa 1. I was ready to give up on this till I made a slight change in the programs. Evident is the FM radio band MHz at center of plot:. Next is a scan of the 1MHz output from my square wave generator out to 50MHz:.
Just run PyDSA exe from within the directory structure provided:. So your mileage may vary. It does however work well in single scan mode. If you have any questions leave a comment. Happy to help. March 28, by rlaude. Getting things hooked up again it would seem all is well but needs a calibration re-visit. Looking at the VCO ramp linearity the breakpoint adjustment was a bit off. Below, once the ramp breakpoint is optimised and the sweep cal pot tweeked, we find a spectral range quite near a maximum of 80MHz…not bad:.
The linearity is not quite where it needs be on above plots but I think could be coerced a bit closer with a few more iterations of pot adjustments as they tend to interact with each other.
Possibly it could use a few more breakpoint additions to the circuit to compensate for the inherent nonlinearities of varactor tuning…not really an issue. It is after all, a simple spectrum Analyzer. I re-visited that circuit a few days ago and came up with a better, working solution. This is illustrated below Rev C :.
Find a larger version of the schematic above HERE …. Along with this change I would recommend using a multi-turn pot for the center frequency adjustment R If not you might want to add back in the fine frequency control which I had previously removed.
April 29, by rlaude. Well this time I managed a self inflicted circuit error. Works a lot better now.Aaronia spectrum analyzers stand for high quality, innovative design, intuitive software and high cost-efficiency.
The portable spectrum analyzers of the SPECTRAN series stand out through their compact size, attractive prices, wide frequency ranges and the free, included analysis software. His weight of only g makes him perfect for any measurements on the go. The high-quality aluminium case allows for passive, fanless cooling of the system.
They are available in eight different versions, covering frequency ranges from 9kHz to 20GHz. The series allows for the unlimited, remote measuring and recording of RF signals up to 20GHz. Eliminate the trips to difficult to reach locations and get full access to all your measurements remotely. Available as a sweep or real-time analyzer in a total of 11 different versions, all with passive cooling.
Possible areas of application are military operations, counter surveillance, aerospace, mining operations, construction sites, research and development. The devices can withstand anything from pouring rain, extreme temperatures to extremely dusty or dirty environments.
You can overcome any challenge with these spectrum analyzers.
They offer powerful, rugged hardware. The laptops have an extremely bright Full-HD Touchscreen and an internal, high-end spectrum analyzer with a frequency range of up to 20GHz. The Command Center is the most powerful and quick spectrum analyzer ever built by Aaronia and offers up to MHz real-time bandwidth, combined with a lot of hard drive space and the ability to record any measurement-data without any limits.
A special, modified version of our software combined with the two bright Full-HD screens enable you to keep everything displayed and to notice even the shortest signals. Due to the low weight and the optional, integrated battery, the OEM version is easy to use on planes or drones.The Original MSA, mated with a laptop computer.
Not pretty, but works quite well. Updated Aug.
Build a 1000 MHz RF spectrum analyzer (inexpensively)
That half is the computer you are using to read this. The processors and displays are very expensive portions of modern spectrum analyzers, and those functions can be replaced by your home computer.
The computer's monitor is the Spectrum Analyzer's display. The other half is the MSA hardware, to be constructed as seen in the photos. The MSA Software is free to download. Previous visitors to this Site will notice significant changes. The previous designs and web pages are retained in the MSA Archivesfor those who need the references.
The Original MSA will continue to be supported in the software. The title of this page and the opening paragraph seem to indicate that the Function of the MSA is a Spectrum Analyzer with operation limited to MHz.
This was my original concept and design goal. However, software and hardware additions have allowed the MSA to provide many more Functions than just that of a Spectrum Analyzer.555 Super-Regenerative IF Spectrum Analyser
The Functions depend upon the level of construction. Average dB. Selectable in steps. Monitor can be any size, but MSA software uses by pixel resolution. Windows 98 or later. The Liberty Basic is free, but it will nag you to buy it. Go visit their web site at www. Construction Hints. Hints on constructing the SLIMs.
It may save you a lot of potential grief. A description of screens, controls, and operation. Technical Analysis of the MSA. In-depth circuit analysis. Very handy for troubleshooting the MSA. Temperature Testing of the MSA. Use it, but many links don't work. I will repair them as time permits.