SDR Television v1.0.6
Simon Brown • February 13, 2026
SDR Television v1.0.6
February 13th, 2026: A new kit, lots of receive improvements since the last official kit. As with any software project, there's always room for improvements and new features, but for now here's a stable solution which works well with the QO-100 satellite.
Downloads are at the bottom of this page.
Release Notes
v1.0.6
Transmit
A FIR filter at the end of the IQ generation processing was too narrow and too sharp, must have been degrading reception of signals created with previous kits. This filter is now wider and uses fewer taps.
Pluto Support
(This is part of SDR Console.) The FIR filter support for the Pluto has been corrected:
- Images reduced if not completely removed.
- Transmit now works reliably when the Pluto bandwidth is greater than 2 MHz.
- The digital filter uses a FIR design from Analog Devices, taken from the file ad9361_baseband_auto_rate.c in the libad9361-iio library.
- The analog filter is unchanged. It will appear wider than expected to allow for roll-off.
With QO-100 and other DVB-S2 operation there really is little if any need for any filtering.
v1.0.5
Receive
- Added optional inversion of the incoming signal inversion (swap I and Q).
Transmit
- Now setting the Quantization Parameter (QP) to the default value of 26. I had come across this before but never really understood what it does. I was just querying the value, not trying to set it.
https://www.oupree.com/knowledge/Whats-Quantization-Parameter-QP-in-Video-Encoder.html
v1.0.4
Receive
- Improved initial frequency detection when searching for a signal.
- Optional advanced signal detection options.
- Found and fixed a bug causing a lockup when a 188 byte packet checksum failed.
v1.0.3
Testing
- Added optional Gaussian noise when in loopback mode, this is for development use only.
User Interface
- Added display of elapsed time to the Receive Audio window. Gaps in reception of up to 10 seconds are allowed. Later use of AI may support a 'speech quality' metric, determined from quality and technical content.
- Added tuning bars in the spectrum, these show the frequency and symbol rate for the current mouse position.
- Added extra categories in the Log window, now Main, Radio, Transmit, Debug.
- Audio and video windows optionally hide controls when the cursor leaves the corresponding window.
Receiver
- Added initial Gardner timing error detection (TED).
- Changed AGC algorithm, target output now ~0.7 using 32-bit IEEE floats.
- Redesign #1 of the IQ to Transport Stream (TS) processing, still plenty of refactoring to do.
- Changed default LDPC algorithm.
- Fixed BCH implementation which was not correcting any bits, also not detecting errors.
- Changed default matched filter (RRC) defaults.
- Added Quadrature Imbalance correction.
- Interpolation filter roll-off dynamically updated with the value in the base-band header byte MATYPE-1. This value is also shown in the Decoding overlay and Decode Status window.
- Refined the list of receive filter bandwidths.
AGC
- Added selectable reference level.
- Added alternative algorithm, Feed forward (the default algorithm is Feedback). Feed forward is experimental.
- Searching for a signal in the noise uses considerable CPU, especially at higher symbol rates. The spectrum data is now used to detect the possible presence of a signal, thus saving CPU while a signal is not present. When a signal is believed to be present:
- The arrows at the top, bottom of the bandwidth display are filled in,
- The receiver is enabled.
Transmit
- The transmitted BB Header roll-off value in byte MATYPE-1 now matches the roll-off value used in the filter, rather than preset to 0.35.
- Removed 12-bit camera formats, problem discovered using a new DELL laptop.
- Added optional transmit signal inversion (swap I and Q).
Pluto
- Pluto RX FIR Filter gain set to 6, example: "RX 3 GAIN 6 DEC 1 TX 3 GAIN 0 INT 1 ..."
- Removed Pluto/Libre bandwidths below 1.5 MHz.
- Changed filter taps for bandwidths above 2MHz, was 64 now 128. Signal is now cleaner, ~40dBm SNR.
From the AD9363 product sheet: "The AD9363 transmitters use a direct conversion architecture that achieves high modulation accuracy with ultralow noise. This transmitter design produces a best-in-class Tx EVM of −34 dB, allowing significant system margin for the external power amplifier (PA) selection."
v1.0.2
- Improved receiver sensitivity, still not as good as it can be.
v1.0.1
- Fixed fatal bug in receive audio AGC when the output device sample rate was 192kHz.
Download
This minimum version of SDR Radio is shown below. Only download if SDR Television displays an error message when starting.
SDR Television
Download v1.0.6 from either:
- OneDrive: SDR Television V1.0.6, 64-bit, 2026-02-13_0531.exe
- Dropbox: SDR Television V1.0.6, 64-bit, 2026-02-13_0531.exe
SDR Radio
V1.0.6 requires a SDR Radio 64-bit kit build 3972 February 10th, 2026 or any newer kit.
- OneDrive: SDR-Radio V3.4, 64-bit, 2026-02-11_1214.exe
- Dropbox: SDR-Radio V3.4, 64-bit, 2026-02-11_1214.exe
History
SDR Television v1.1.6 September 14th, 2026. To avoid confusion with the test versions of 1.1.5, this kit is now 1.1.6. Receiver Improved Gardner timing recovery. Improved Sum-product decoding. Redesigned soft decoder. Redesigned RRC matched filter. Note: this kit should be able to gain a dB or so sensitivity when detecting the frame header. v1.1.6 will have even better frame detection, hence better weak signal decoding. LDPS Settings, important! Open this page, select Defaults . There is no need to adjust the Sum-product optons, these options are only for development and may be hidden in future kits. Transmit Provider changed from SDR Television to SDR TV, some receivers only display a maximum of 18 characters in the provider field. Downloads are at the bottom of this page.
Improving DVB-S2 PLHEADER Detection at Low SNR Reliable detection of the DVB-S2 Physical Layer Header (PLHEADER) is one of the first challenges faced by a DVB-S2 receiver. Before the receiver can decode the payload, it must determine where a physical-layer frame begins, establish carrier phase and frequency sufficiently accurately, and decode the signalling contained in the PLS code. This becomes particularly interesting at very low SNR. I have been comparing two approaches: A traditional differential SOF/PLS detector. A new coherent, maximum-likelihood-oriented PLHEADER detector designed to exploit substantially more of the information contained in the DVB-S2 header. Both methods are trying to answer essentially the same question: At what symbol does the DVB-S2 PLHEADER begin, and what carrier frequency and phase best explain the received 90-symbol header? The difference is how much of the available information they use to answer that question. The full PDF is here .
Project for 2027? Love it or hate it, FT-8 is here to stay. I use WSJT-X to monitor 2m and sometimes 70cms. As a software developer, it's always rewarding to use one's own software. So I just asked ChatGPT whether it (he, she, they) even knew about FT-8. The response was amazing. So, this could be the start of a project which is also used for EME and meteor scatter modes. Read on dear reader, read on.
August 27th, 2026 Default Audio Device When changing the default audio device selection in Windows, SDR Console was following the change but not reapplying the latest volume change. Example: I start playback, adjust the volume, then after a while enable my Bluetooth speaker an go outside. When the speaker is enabled SDR Console switches but didn't apply the change in volume. RDS processing AGC replaced with normalisation, Hilbert filter redesigned. Shouldn't make much difference. MIDI Startup I believe I have found the cause of the slow start of SDR Console. As part of the SDR Console startup I always call midiInGetNumDevs() to get the number of attached MIDI devices, even if the user hasn't enabled MIDI. At some stage in 2026 Microsoft introduced a bug where the first call to midiInGetNumDevs() after starting the computer results in blocking all asynchronous activity if there are no MIDI devices connected. If there are MIDI devices connected then it returns after ~100ms. I now only call midiInGetNumDevs() on startup if there are user definitions. Some programs are experiencing even worse behaviour. There should be a Windows update soon with a fix, but for now the kit below should resolve this problem in 99% of cases. Downloads Download beta kits here .
QO-100 Footprints
SDR Television v1.1.4 User Interface Rearranged ribbon bar, added Forward Error Correction (FEC) to the Home panel. Receiver Currently trying to improve LDPC decoding for low SNR. Part of this work involves reducing CPU load in the LDPC decoder. Planning to add advanced decoding in v1.1.5. Changed the list of FEC / LDPC algorithms, removing min-sum and min-sum correction. Optimised offset min-sum algorithm to reduce CPU load. Optimised Bose-Chaudhuri-Hocquenghem (BCH) processing. Added sum-product. Corrected LLR soft scaling for QPSK. Changed default RRC filter length to 12 symbols, previous value of 30 was too long. Updated Feed-Forward AGC with a design from CoPilot. Optimised Gardner TED RRC filter length, now 25 taps. Increased the receive RRC filter rolloff factor by 25% to capture more energy with weak signals. Reset LDPC after 1 second of inactivity. FEC - LDPC There are now two LDPC algorithms, Offset min-sum, and Sum-product. Sum-product is more sensitive than offset min-sum but currently doesn't work at all for FEC rates lower than 1/2 (1/4, 1/3 and 2/5). When sum-product is selected and the rate is lower than 1/2 then offset min-sum is used. The default damping settings for sum-product are shown below. The aim is to work on sum-product with the help of ChatGPT in 2027 to get the maximum possible sensitivity. Downloads are at the bottom of this page.
July 26th, 2026 Reuter RSR200B Added initial support. Fobos Finalised support for Fobos SDR, only the Agile firmware is supported. Some early Fobos SDR units had HF2 and HF1 swapped on the case printing. FFT When using NVIDIA CUDA for the FFT the returned buffers now use memory from the heap rather than pinned memory (*). Reduced the CPU load in the FFT Helper DLL. The data from the FFT (CUDA, IPP, OpenCL) is processed to match the display DIPs. When running Broadcast-FM with x4 resolution there were 550 FFT bins per display pixel (DIP). These 550 bins were averaged which takes quite some processing, especially when running a matrix display with many receivers enabled. I now down-sample the bins to a maximum of (about) 32 which doesn't affect the display or any DSP but does reduce the CPU. Frequency Database Loading of the frequency database into memory-mapped backing now much faster. Pluto TX Doppler support for Pluto / LibreSDR. Have tested this by adding debug info, seems OK 🙂 . RDS Added variable font size in the RDS editor window. Forced uppercase of PS text in the RDS Editor removed. Change to RDS Logfile updates while the editor is open & visible. Updates are now allowed, previously not so. Recordings Fixed font size error in the playback, navigation window (was incorrect logic). When starting the video recorder a sanity check makes sure the selected folder exists and is accessible. Satellite Satellite definition file format has changed, no need to update your settings but support for the new OMM (.xml) format is included. I'm hosting satellite data on my (new) Akamai server, these is currently a cache of the Celestrak data. I'll add a web page soon which explains what's been happening. Transmit Audio mute is now a per-profile setting. Other Fixed an error opening the matrix display while the SDR was already started. Crash when selecting "Configure" from the Select Radio window fixed. Does not create an error when the graphics driver restarts.
SDR Television v1.1.3 User Interface Fixed erroneous cursor flicker in Settings help text and Receive, Transmit panes. Fixed error in the spectrum squelch logic. Minor fix/improvement in QPSK LUT lookup for low values. Receiver Use highest possible quality decimation for symbol rates of 333ksps and lower. Added optional Doppler correction for LEO/MEO satellites such as MARMOTsat (July 2026). This will most probably be tweaked when the DVB-S2 transmissions started. Downloads are at the bottom of this page.
