As you know, SDR radio basically consists of two components, the radio hardware and the software used to process the signal. As SDR radio hobbyists we typically spend a lot of time looking into the specs of the hardware, but we don’t but as much consideration into the software side of things. The software can be just as important as the hardware we choose to get good performance from a SDR radio system. We often turn to some of the free software offerings to get started in SDR hobby. While there is absolutely nothing wrong with that and we greatly appreciate the work these authors has put into their efforts. However, you have to keep in mind that some of these programs use DSP (Digital Signal Processing) engines developed for SDR use that have been handed down for many years and have only been improved slightly over their original incarnations. With that in mind, the developers at SDR Applications set out to create a new high performance DSP engine for better SDR performance from your SDR hardware. That product is now called Studio1 and is distributed by Woodbox Radio. Studio1 is not a free application. However, this is a good thing because unlike the free offerings, this means that for this to be a viable product the developer will have to be committed to it’s continual improvement and provide support for its customers. In a nutshell Studio1 has gotten a good start on meeting those goals. The Studio1 software is impressive with its advanced DSP engine and gorgeous user interface. You also get free email support directly from the developer as well as free upgrades up to the next major release. To help protect your investment, Studio1 uses a security dongle to help insure that you won’t find unauthorized copies of Studio1 floating around the internet. The security dongle also allows you to install the Studio1 software on multiple machines if you need to. Simply install Studio1 on the additional machine and plug the dongle into the machine you wish to use. This is much better than having to license the software for multiple machines as you sometimes find with other paid software applications. Ham Radio Science has had the pleasure of using the software for a few weeks and here are our first impressions.
Supported Radio Hardware
First of all, Studio1 supports a fairly wide range of SDR radio hardware. Here is a brief list of SDR hardware supported directly by Studio1:
Microtelecom Perseus – Elad FDM – S1
RFSpace SDR-IQ and SDR-14
FunCube Dongle and almost all the soundcard based receivers (Softrocks etc.)
Support for the following receivers is planned (for the near future): Winradio Excalibur – RFSpace NetSDR – RFSpace SDR-IP
However Studio1 will typically support any receiver where there is an ExtIO.dll file available for the receiver. This done by simply dropping the ExtIO.dll file and any associated files with it into the Studio1 directory. If there is only one ExtIO file available in the Studio1 directory, Studio1 will automatically select it on start up. If you have more than one ExtIO.dll file in the Studio1 directory, Studio1 will allow you to chose the ExtIO.dll that you wish to use. Since Studio1 supports the ExtIO.dll standard we were able to use Studio1 with such receivers as the RTL2832U dongle and the Alinco DJX11 with their 3rd party ExtIO.dll files along with the radios appropriate USB drivers. Even though Studio1 design goals were to squeeze every ounce of performance out of high performance SDR hardware, we found that Studio1 significantly enhanced the performance of less expensive SDR radio hardware as well. This can be primarily attributed to the Studio1 enhanced DSP engine.
The DSP Engine
At the heart of Studio1 is a new advanced DSP engine. Here are some of the features of the DSP engine:
- Very efficient DSP decoding engine that allows the use of older CPUs such as Pentium 4 machines.
- Studio 1 the spurious/alias free dynamic range is greater than 130 dB compared to around 70 dB that is provided by some of the free offerings. (the spurious free dynamic range influences the capability of the receiver to resolve small signals in presence of in-band
- A selectivity filter with an ultimate rejection greater than 140 dB.
- A unique distortion-free double stage AGC with fully adjustable parameters.
- Multiple notch filters with BW adjustable down to 1 Hz, Notch Lock feature.
- A unique synchronous AM mode with selectable/adjustable sidebands, dedicated PLL input filter, and selectable PLL time constants.
- FM implementation available with Band Width from 0 to 192 KHz and 4 sub-modes: NFM (narrow FM), MFM (medium FM), WFM (wide FM), SWFM (stereo wide FM); 50, 75, 520 us de-emphasis, post demodulation adjustable pass-band filter, monitoring grade stereo demodulator and sensitive RDS demodulation-decoding.
- SNR (stereo noise reduction), featuring a proprietary noise reduction algorithm for stereo broadcast which.
- FM AFC / AFT.
- Unique AM “soft-filter” with old-style IF response emulation (tube like).
- Accurate spectra with 8 selectable FFT windows: Hann, Blackman, Hamming, Sin^3, Sin^5, Nuttall, Flat Top P401, Rectangular (the Flat Top P401 allows precise amplitude measurements), selectable overlap, adjustable speed and averaging.
- Noise Reduction, Wide Noise Blanker, Narrow Noise Blanker.
- Digital and analog style S-meter with calibration; peak and RMS indication, peak hold.
- FM tuning meter.
- dBm readout.
- Distortion free output limiter in all modes excluded SWFM.
- Arbitrary input sample rate up to 4 MS and above.