Posts by SWL - markro92

    @G0MJW: yes, that's exactly what happens.

    @R0AU: If LDPC takes too long, maybe you've chosen the wrong modcode from the list. Also, weak signals mean more CPU load for LDPC decoding.

    Next version won't have the list, because it's coded inside the DVB-S2 frame anyway. I'll also implement multithreading for the LDPC decoder, so it will benefit from multiple CPU cores.

    Looks good, but no carrier lock. Can you increase the Loop gain temporarily?

    If you have lock, try reducing gain and damping sliders again.

    Also try re-checking the enable checkbox. On RTLSDR the Signal needs to be centered very well.

    Yes that's correct :) i thought about including an option in the config file for that, but i didn't want to keep you waiting any longer. definitely next version, which will be very soon, i think next week. I'm working on multithreaded LDPC decoding, because that's the bottleneck right now.

    ALso, i forgot to include the readme.txt, i'll update it and put it into the next update.

    @Tony: you can set the color in the config.ini file.

    ui_iqplot_rgb = 10 70 100

    the 3 numbers are red/green/blue channels ranging from 0 to 255, where 0 is low, and 255 is high intensity.

    For example 255 128 0 would be orange, 0, 0, 64 would be dark blue etc...

    Version 2.0.12



    • Added Support for 8PSK modcodes
    • Added Equalizer (improves SNR by reducing channel impairments)
    • LDPC decoder performance optimizations
    • FFT performance optimizations
    • Saving last settings on a per-device basis (like freq, gain, filter, bw)
    • Showing Ku-Band Lo/Hi frequencies next to IF frequency.
    • Fixed maximum symbolrate being limited to 8000ksym/s even if the config value was set higher
    • Made IQ Plot color changeable via config file
    • Minor UI Changes

    I haven't tested this version with Es'Hail 2, only used commercial satellited for testing.

    Also, there could be problems with saving/loading settings for certain device types. I haven't tested them all.

    There is a new MOD_LOCK checkbox inside the debug section, that's for locking the current modcode. It could help keeping weak signals locked, i left it in this version just in case.

    As always, let me know what you think. If there are major problems, i'll release a fix as soon as possible.

    @VU3BCN: I'm using different signals from many satellites for testing purposes. Normal FTA transponders on TV Satellites are no different from Es'Hail 2 Amateur TV signals, except the larger bandwidth. But there are also SCPC (Single Channel per Carrier) Transponders on commercial satellites that i use for testing. High bandwidth transponders are hard to decode without a hardware solution, due to the lack of computing power. I've optimized my software quite well, however there's still headroom for improvements. I'm using Intel VTune for spotting performance issues, and i write custom assembly code for critical sections, using architecture specific SIMD instruction sets like SSE/AVX.

    My original goal was to develop open source hardware, and implementing the demodulator in a FPGA chip. I'll definitely do that, but right now i'm mainly working on this software due to the positive feedback from the community.

    Hi all!

    Sorry that i didn't write anything in this forum for a while.

    I just wanted to say that i'm still working on this project, even if i didn't finish as much work as i wanted. I'll definitely release a new version this month. I'm currently working on 8PSK support, and there will be fixes for annoying things, for example saving application state like bandwidth/frequency settings, and changing local oscillator frequency, so that you don't have to calculate frequencies manually.

    Kind regards,


    3b8fa : (Pat) Hi, we could try using Teamviewer, i'll take a look at it tomorrow if you send me the ID and password.

    To be honest, your signal looks quite strong in the FFT plot. It must be something with the symbolrate being wrong. DId you use M&M / (Müller & Mueller TED) for timing recovery? that's necessary for RTLSDR sticks to receive the beacon. If you haev Timing lock, you should atleast see a circle in the IQ Plot.

    @SWL-ALAIN: can you send me a screenshot?

    i want to know the device name from the dropdown box.

    The part called 'hwVer' should only be one of these:

    1. #define SDRPLAY_RSP1_ID (1)
    2. #define SDRPLAY_RSP1A_ID (255)
    3. #define SDRPLAY_RSP2_ID (2)
    4. #define SDRPLAY_RSPduo_ID (3)

    That's why i thought that the RSP2Pro wasn't supported.

    Maybe RSP2 and RSP2Pro share the same ID.

    I only tested with RSP1A, so it's a good thing to hear that they all work.

    Increasing damping for short periods of time helps, too, while keeping the gain value relatively high. High symbolrates lock faster, because there are more symbols to average out noise, that's how the loop filter works.

    Version 2.0.11



    • Added Support for Airspy Mini and Airspy R2
    • Added Symbolrate presets (with config params)
    • Added Symbolrate min/max setting to config
    • Made SDRPlay channels A/B selectable via config file
    • Made UI style selectable via config file
    • Fixed crash on app exit due to double-free
    • Fixed FFT Plot display only showing half of the spectrum
    • Improved FFT Plot scrolling performance (using ringbuffer instead of memcpy)
    • Minor GUI changes (S2 Modcode info)

    The next version won't take as long as this one, there are still many smaller things to improve. There will be more changes to the FFT Plot, because in the long run, transponder stats / signal infos will be shown there for each transponder. Maybe left click for moving the spectrum, and right click for selecting transponders. we'll see. For the next smaller update, i'll probably automate things like FEC / Modcode selection and centering / locking.

    For now, i'm interested about what the Airspy owners tell me :)

    @IU2KAC: SNR meter is in the TODO list very long now, i'll need to do that soon. Probably in the next version. (2.0.12)

    @DB8TF: auto scanning the whole spectrum sounds like a great idea, but i think that will be implemented a bit later, when i also do multi-signal reception. That means in version 2.1.0 which will take a bit time, because it will mostly contain new features instead of fixes.

    Edit: i kniow that i didn't implement saving of last used fequency and gain setting. definitely in 2.0.12 :P

    DD0KP : can you tell me the exact CPU model? quadcore CPU isn't very specific. I think that this PC will be okay but not great. 4 cores or more is what i recommend, and it should have all features my software needs. But what concerns me, is that they don't even write the exact specifications on their homepage.

    Edit: Ok i looked it up, it's a Intel® J3455 QuadCore. It won't work with my software, because it has no support for SSE4.1. I also wouldn't expect very much from this hardware otherwise. That thing isn't worth 400EUR. Maybe the only thing justifying the price s that it's a bundle with keyboard, mouse, monitor.

    Do you really need a bundle? This thing also has passive cooling (TDP is 10W), so i don't think that the CPU is great at all. 4GB of RAM also isn't very future proof. We have win10 computes at work and upgraded the RAM capacity to 8GB, and they are also used mainly for office and surfing the internet. Windows also almost eats up 1GB itself.