Tagged: drm sdr

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Have your own HAM SWL radio station!

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Gadget of the past? HAM SWL radio station!

In most cases we write posts about unique designs and ides, which are useful for advanced level HAM SWL radios, e.g., this or that posts on software defined radio (SDR) technology. But what about the beginners? Well this post is for them! Ready, steady, HAM SWL Radio!

Some weeks ago I was surfing the internet looking for some new ideas for a special issue of Quadrus SDR. It was easy to find a creative idea for my problem, and to prove to my family that HF broadcasting is alive. We can access high quality radio service there based on new, digital operation mode (i.e., DRM), which has a very useful community for SDR fans. When I started to deal with HAM SWL radio, there were no opportunities such as the internet. It was ooch… 35+ years ago. We – the members of the community – talked to each other only using the radio at the club station or using our self-made radios at home, but it was an amazing experience that I never forget. I had my own HAM radio station at home – built with my own hands from scratch – with CW capability for the 80m ham radio band. Lovely, isn’t it? (and I was 17 years old when I made this…)

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I have two sons. They are not interested in making, but they are professional in using gadgets. Like every teenager nowadays. Maybe my father said the same thing about my HAM radio equipment. Gadget.

Do or do not, there is no try

So, what about beginners? I found a very good post about how to start this kind of a hobby. Hobby? No! This is a way of life. I could not summarize this better then Gregory L. Charvat:

“The only way to get started is to build something. Start small, check out the QRP community, try making a single-conversion receiver, and move up to something with a crystal IF filter. Borrow and scale circuits from books such as these:

Or leverage complete ICs and modules like those from Mini-Circuits.  There is nothing like making that first long distance contact (DX) on radio gear you created from scratch.”

You can read the whole article on Hackaday.

But if you are more of a computer geek, you can switch to software implemented radio and start with less complex and less expensive SDRs or a professional one like Quadrus SDR from our webshop. Even I experienced that old fashioned radio moment Gregory mentioned above, when I first received a DRM station from Mubay, which was a very nice feeling for my radio infected heart. You can see the report on this reception here in the Quadrus SDR blog:
http://spectrafold.com/quadrus/radio-software/sdr-drm-receiver/

Further reading on DRM, the new digital HF broadcast technology:
http://spectrafold.com/quadrus/go/whitepaper-drm-broadcasts/

And don’t forget to share your success stories or questions regarding SDR issues with us on our Facebook pageTwitter page, or G+ community page. Be social; whatever is your preferred platform, we are there !

Bertalan, HA6QU

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Sensitive SDR receiver

Sensitive SDR receiver for sensitive information

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[Sensitive SDR receiver for sensitive information]

Sensitive SDR receiver based on the DRU-244A digitizer SDR hardware platform

The DRU-244A digitizer board was designed and implemented for building radio receivers. It contains a 16 bit resolution low-noise Analog-to-Digital Converter (ADC). It has a low-noise input preamplifier and an input attenuator in front of the ADC. The low-noise preamp provides input sensitivity as low as -111 dBm in SSB reception mode with 2.1 kHz bandwidth and 10 dB SNR. With external preamplifier it could be as low as -122 dB. If you would like to see more detailed test results on SDR receiver sensitivity click here:
http://spectrafold.com/quadrus/digitizer-hardware/sdr-receiver-sensitivity-test

Practical results for receiving weak signals

I’ve already made some practical tests with my very simple inverted-V shaped wire dipole antenna. It was used in the country side, so there was less human made noise than in the crowded city or urban area.

Sensitive SDR receiver as long range DRM SDR

If you are not a professional radio enthusiast with a vast knowledge of exact broadcasting carrier frequencies, one of the easiest ways to find some DRM radio stations is to just look for its unique spectrum in the HF band. The DRM spectrum is a very typical, noise like, wide band signal. This is exactly what I did; I simply connected the antenna to my receiver through a 30 MHz low-pass input pre-selection filter, and started visually looking for DRM radio signals in the spectrum. I was really surprised when one of the first signal received turned out to be be coming from India and the next one was from South Africa. Not bad. The SDR receiver seems to be real sensitive if I am able to decode these signals in the middle of Europe.

drm01 drm02

If you are interested in how the SDR receiver was connected to the Dream DRM decoder software, please read these posts:

http://spectrafold.com/quadrus/radio-software/virtual-audio-connection/

http://spectrafold.com/quadrus/radio-software/sdr-drm-receiver/

Sensitive SDR receiver for secret transmissions

One of my other favorite signals in the HF spectrum is the UVB-76 Buzzer on 4555KHz.

https://en.wikipedia.org/wiki/UVB-76

http://priyom.org/military-stations/russia/the-buzzer.aspx

http://www.wired.co.uk/magazine/archive/2011/11/features/enigma?page=all

As the frequency is well known, I could simply dial it in to the SDR receiver software, and immediately see the transmission on my screen and hear the famous “Buzzer” tone on the speaker with very high Signal-to-Noise Ratio (SNR).

Receiving the UVB-76 Buzzer on 4625KHz with sensitive SDR receiver

There are a lot of mysterious signals in the HF spectrum. The sensitivity of our receiver – especially with an external, low-noise per-amplifier and a good antenna – makes it possible to listen to even the most remote signals.

listener Contact014

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QUADRUS SDR radio receiver development platform

Quadrus SDR Blog

[QUADRUS SDR BLOG]

Latest relevant discussion | QUADRUS SDR blog

You could find some latest relevant discussion in the QUADRUS SDR blog about the technology and its application.

 

QUADRUS SDR | Phase-coherent Multi-channel SDR

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Phase-coherent SDR hardware | Multi-channel SDR receiver | digitizer SDR hardware and receiver SDR software | QUADRUS SDR platform
Phase-coherent SDR hardware | Multi-channel SDR receiver | digitizer SDR hardware and receiver SDR software | QUADRUS SDR platform

QUADRUS SDR | Phase-coherent Multi-channel SDR

The QUADRUS SDR platform is complete ready to use integrated platform for advanced SDR software received implementation. It contains all the elements for a complete SDR receiver functionality. The phase-coherent SDR hardware digitizer with Windows driver and open API. The multi-channel SDR software receiver with advanced signal processing and open programming and remote control interface on TCP/IP. It can be used as a single element or as part of the higher level integrated system. During its entire lifetime already proved capabilities with lot of deployment in mission critical environments. Now it is available for the public use and further integration developments.

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Phase-coherent SDR hardware digitizer

The DRU-244A high speed phase-coherent digitizer SDR hardware multi-channel SDR hardware. With on board input leveling, low noise preamplifier and multi-channel SDR digital down conversion (DDC) capability. The DRU-244A SDR hardware has outstanding dynamic range performance with carefully optimized design for SDR hardware implementation. The high-performance SDR hardware design is the combination of high bandwidth and high dynamic range with excellent sensitivity. QUADRUS SDR hardware enables demanding applications such as RF/IF direct sampling SDR receiver. Excellent spectral purity in combination with gain control. The DRU-244A is ideal for advanced digital radio SDR software receiver implementation. Originally developed for professional signal and communication intelligence and spectrum monitoring and management application by Sagax Communications.

DRU-244A phase-coherent SDR hardware digitizer card
DRU-244A phase-coherent SDR hardware digitizer card

Multi-channel SDR software receiver

The SRM-3000 is a ready to run high performance multi-channel SDR software receiver application for the QUADRUS SDR receiver platform. Particularly suitable for spectrum monitoring and management,  communication and signal intelligence. It allows simultaneous monitoring and recording multi-channel of modern digital narrow or wide band signals. While the streaming of the IF or the demodulated audio signals can be streamed to the TCP/IP interface. The SDR software receiver has its application programming interface (API) for higher level integration. It combines state-of-the-art user interface technologies with the latest features in digital signal processing thus providing advanced SDR software receiver platforms available today. It was developed by Sagax Communications for search and intercept tasks in signal and communication intelligence applications and deployed to the field in several missions.

SRM-3000 multi-channel SDR software receiver application
SRM-3000 multi-channel SDR software receiver application

Read more phase-coherent SDR hardware multi-channel SDR software: QUADRUS SDR BLOG.

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