#RFAnalyzer

[digilogic-system]

Communication Tester from Digilogic Systems

Digilogic’s Communication Tester is a modular, COTS, multifunction, programmable, benchtop Automated Test Equipment that supports a wide range of real-time RF and microwave stimulus, Test and Measurement applications. The system seamlessly supports applications from 250 kHz to 6 GHz with “in-the-box” upgrades that can extend the measurement up to the 26.5 GHz frequency range.

Digilogic's Communication Tester includes a Two-channel High-Speed Oscilloscope, an RF Vector Signal Generator, an RF Vector Signal Analyzer, an RF Power Meter, a Digital Multi-Meter, a Two-channel Audio Analyzer, an Arbitrary Waveform Generator, a Unit Under Test (UUT) Control App and many more.

Overall, Digilogic’s Communication Tester, a modular ATE, is essential for verifying the functionality, quality, and security of RF devices, ensuring reliable communication in military, tactical, and aerospace applications.

For any queries (or) to request a quote, please contact us. Phone: Hyderabad: (+91) 40 4547 4601 Bengaluru: (+91) 80 4975 6034 Website: https://www.digilogicsystems.com/ Email: info@digilogicsystems.com

Stay connected with us on our social media channels for the latest updates!

LinkedIn: https://www.linkedin.com/company/digilogicsystems/ Facebook: https://www.facebook.com/digilogicsystems Instagram: https://www.instagram.com/digilogic_systems/ Twitter: https://x.com/DigilogicSystem Youtube: https://www.youtube.com/@digilogicsystems

"Experience the Future of Communication Testing – Invest in Digilogic’s Communication Tester Today!"

[virusfriendly]

SDR Research

Tools

GQRX - Spectrum Analyzer

RFanalyzer - Spectrum Analyzer for Android

Universal Radio Hacker - Investigate Wireless Protocols like a boss

ooktools - On-off keying is used extensively in IoT projects

fldigi - I'm not a big fan of fldigi, but its there for when you need to demodulate a common signal

Tools for more specialty purposes

Salamandra is a tool to find spy microphones

rpitx is a RF transmitter for Raspberry PI

Tactics

You don't need to learn DSP, or get your Ham license to explore radio signals. I didn't. You could even explore interesting signals such as vehicle key fobs without learning either, but learning these things will increase your understanding of signals and aid in your ability to go beyond the limitations of your tools.

Digital Signal Processing

The Scientist and Engineer's Guide to DSP was my introduction to DSP and I highly recommend it. Its free online and can be purchased in physical form.

Think DSP in Python is on my todo list. Also free online can can be purchased in physical form.

HAM Radio

Though I haven't taken the test yet. Covid was a major interruption in my plans, and I also plan to pass all 3 tests in one day. Using my personal test taking process, I would first start by reading No-Nonsense Study Guides.

Then take a pretest. Its important that you read all of the material before you take a pre-test as the goal is to retain knowledge, not just memorize a test. Most of the study should be reading/practicing the material, with few pre-tests as self assessments.

There are plenty of apps on Android (and I imagine IOS) that you can use. You need to get 74% to pass the exam, but I always shoot for 90%. If you get 90% on the pre-test, then move on to taking the actual exam.

If you didn't get 90% on the pre-test. The pre-test should be able to break down your score across various sections. Note the sections you're weakest in. From here, I would recommend switching over to the ARRL study guide as they are more detailed and only study the sections you're weakest end. When you complete all those sections, then take another pre-test and repeat until you're ready to take the exam.

Techniques

Accuracy

Radio is a science, but the tools that we can afford as hobbyists are not accurate. The three issues I face is drift, noise, and clock.

Drift occurs typically from your SDR getting hot and is a problem that grows across the session. To counter drift, you'll need to recalibrate your SDR to a Nation Weather Radio station. Find the frequency used in your area and tune to that frequency. You'll notice that you're probably a little off, this is the fault of your SDR not the National Weather Radio station. Set the offset of your SDR until your frequency of the station matches the one advertised. You'll then want to bookmark this frequency and check back to it every hour to insure that your SDR hasn't drifted.

Noise can interfere with interpreting weak signals (either distant, low powered, or both). To reduce noise and improve your signal collection, I'd suggest these guides for reducing on-site noise sources and external noise sources.

Signal Identification

Most signals are standardized or frequently used that dont require extensive analysis, but just identification.

The Signal Identification Wiki is a great place to start, and if that doesn't work, check out the sub-reddit r/signalidentification

This is an archived site that has a collection of digital signals that you could test your demodulation tools with.

Signal Analysis

Signal analysis is for those proprietary signals. As always, remember your ABC's.

Radio signals are fleeting. If you don't capture them, they may not repeat themselves. Don't worry about demodulating them at first. Capture the signals, and you can demodulate them at any time later.

Even if you're not able to record IQ data, for example you're listening to someone else's remote radio (there are a lot around the world on the internet), recording the audio which can be analyzed by tools such as fldigi.

I should add a lot more stuff here in the future.

The Signal Identification Wiki is a great place to start, and if that doesn't work, check out the sub-reddit r/signalidentification

This is an archived site that has a collection of digital signals that you could test your demodulation tools with.

Other Techniques

Using ooktools

NCC's RF testing Methodology

Wireless DoorBell Ringer and another Doorbell hack

Learn Morse Code

Project Ideas

Passive Radar with SDR

TDOA Transmitter Localization with RTL-SDRs

Other Links

No SDR, no problem! Use other people's radios with GlobalTuners.