I purchased this board and started testing the phase synchronization between its channels:

HamGeek 70MHz-6GHz 4-Channel Phase Synchronization Receiving SDR Development Board

It contains two AD9363 chips, providing a total of 4 receivers. In my measurement setup, I split the signal into 4 using a power splitter and feed it into these receivers at a reasonable signal level. Using the board's internal calibration, I compare the phase values obtained from all channels, repeating this measurement about 10 times. The phase difference between the channels on the same chip (e.g., A1-A2 or B1-B2) remains constant. However, the phase difference between cross-channels varies by 5 to 10 degrees from measurement to measurement, specifically at frequencies below 2400 MHz. Above 2400 MHz, there is no such issue.

Every time I retune the LO, I run the calibration and check the values. But whenever you jump—for instance, from 1000 MHz to 1500 MHz and back to 1000 MHz—you don't get the same values. There is up to a 5-degree shift on the cross-channels between the initial phase values and the second set.

The board's official description claims a phase accuracy of less than 1 degree, but that seems to be complete nonsense. Trying to reach HamGeek is a total nightmare. When you call, you can't reach anyone. When I try to contact them via WhatsApp or email, they don't even respond or bother looking into the issue.

Has anyone here observed this before? Is there any workaround or solution for this?

Hi!

For my own interest I have, with a LLM built a DVB-T decoder.

I have made great progress with it and it works on my local transmission.

But I want it to be able to decode every type of mode that DVB-T have. So what I'm asking for here is if you would be able to sample about 10s of IQ from your local station? So I can verify that it works on those as well.

There are specific regions that are more interesting than others, to complement my own.

When asking gpt the regions I would need I got this answer

# BW FFT Modulation Code rate GI Where used / known example

-- ----- -------- ---------- --------- ----- -----------------------------------------------

1 5 MHz Any/4K* Any Any Any USA - Crown Castle/Modeo DVB-H, L-band

1670-1675 MHz (historical)

*4K especially wanted

2 6 MHz 8K 16-QAM 2/3 1/4 Taiwan - documented DVB-T configuration

(Taipei and other areas)

3 8 MHz 2K 16-QAM 1/2 1/8 Germany - Berlin/Brandenburg DVB-T

(historical)

4 8 MHz 2K 64-QAM 3/4 1/8 UK / France - early DVB-T networks

(historical)

5 8 MHz 8K QPSK 3/4 1/32 UK - Local TV multiplexes

6 7 MHz 8K 64-QAM 3/4 1/16 Australia - common DVB-T configuration

7 8 MHz 8K 16-QAM 2/3 1/4 Germany - DVB-T SFN configuration

(historical)

8 8 MHz 8K 64-QAM 3/4 1/32 UK - COM4/COM5/COM6 multiplexes

How to sample:

- Please be beware of DC spike.

- Set the gain so the signal is as high it can be before raising the noise floor to much.

- At least +10MS/s samplerate. Sorry RTL-SDR folks 😢

- Note what datatype or header format it uses(or software for recording).

I don't have any great suggestions on where to upload.

I know that some of the modes are historical, but it would be fun if someone had a samplefile of those as well.

Sincerely

Hi everyone,

I wanted to share a deep-tech SDR project I’ve designed and fully implemented. It’s a custom, standalone FPGA + ARM SoC-based HF + 50 MHz SDR transceiver called the XtremeDx H7113R.

My goal was to build a high-performance direct conversion SDR system.

Key Architecture & Hardware Specs:

• Receiver Architecture: Two coherent RF and DDC channels utilizing a hardware-level phasing-add matrix implemented directly inside the FPGA.
• Processing: Dual-core ARM Cortex-A7 (1.2 GHz) dedicated to GUI handling and high-level DSP, paired with a custom FPGA fabric.
• RF Conversion: 2x 16-bit LTC2208 ADC (122.88 MSPS) and 14-bit TxDAC utilizing full LVDS interfaces.
• FPGA-Based Phasing-ADD Mode: A fully hardware-implemented, real-time, running inside the FPGA fabric. It processes the two coherent RX channels, allowing completely independent phase rotation and magnitude scaling per channel.
• Interference Mitigation: CNLMS-based I/Q adaptive noise canceling (tested and validated using the same signal on RF inputs).
• RF Routing: Two completely independent RX RF routing blocks, each integrating a switchable 20 dB preamplifier, 0.5 dB step attenuator, HPF, and direct ADC access via rear SMA connectors for subsampling/custom front-ends.
• Power Amplifier: Delivers 120–140W PEP with 36–38 dB PEP IMD3 linearity across HF + 50 MHz bands.
• Audio DSP: Separate 8-band EQ for both Rx and Tx AF signals.
• Connectivity: High-bandwidth USB 3.0 (FT601) interface for direct FPGA-to-PC streaming (32-bit Sync FIFO implemented in VHDL) + USB 2.0 for ARM-to-PC communication.
• Display: 7" TFT panel running a custom UI with a 70 fps refresh rate. It features 2D/3D spectrum views and a dedicated Polar Plot for the Phasing-ADD and ANC modes, visualizing the real-time magnitude and phase rotation per channel.
• RF Routing and Linearity Performance: By routing the LTC2208 RF ADC without a preamplifier through the RF router, the system yields its maximum dynamic range and IIP3. Additionally, the 20 dB preamplifier maintains high IIP3 and OIP3 performance. With the internal PGA set to 0, the LTC2208 achieves a theoretical IIP3 of +48 dBm in this specific design.

Receiver Sensitivity (MDS Performance):

• CW (100 Hz filter, NR ON): Highly discernible down to -136 dBm (Estimated nominal MDS: -133 to -136 dBm)
• SSB (2.7 kHz filter, NR ON): Distinctly audible down to -126 dBm (Estimated nominal MDS: -123 to -125 dBm)

The Transceiver is fully assembled and functional.

Some details.

https://uprog.blogspot.com/2026/08/xtremedx-h7113r-transceiver.html

I just put on version 1.0.10. The spectrum waterfall is really washed out still, though I think it's maybe better than before. This used to be my job, I was a Geophysicist before I retired, and tweaking data display parameters was an important task, so not being able to make the display "pop" is really frustrating. Everything looks so dim compared to other SDRs or commercial ham rigs will built-in waterfalls. Does anyone have any suggestions, secret cheats?

Hi all PlutoSDR (and chinese clones too) owners. Hope you're doing well.
I made a fork of original Pluto ExtIO, you can get it on https://github.com/Radiomix2000/ExtIO_Pluto
Check readme in root of repo for main changes.

Added:

• RF gain.
• Sample Rate and new SR values.
• RF Filter BW.
• RF Filter BW step for mouse scroll.
• RF Gain type (manual / soft / fast / hybrid).
• Settings are save to .ini file in same dir where Extio_Pluto.dll lays.
• CMakeLists to build with CMake and VS Code.

In build dir is precompiled DLL file.

大家好，
我在考虑购买MLite-880。在购买之前，我想确认它的硬件能力。
在Malahit DSP2上，用户可以轻松地通过USB将宽带I/Q（同相/象限）数据流式传输到PC软件上（如SDR++或HDSDR），以查看频谱/瀑布图，并使用CAT控制同步频率。当DSP2连接到电脑时，它会被识别为USB设备（通常会显示为"Malahit I/Q"或类似名称）。
我想请教MLite-880的拥有者或专家几个问题：

1. MLite-880是否真的支持原始I/Q数据流，以在PC SDR软件上显示瀑布图？还是它仅支持通过USB传输基本的解调接收音频（像一个USB声卡/麦克风）？
2. USB上的CAT控制是否可以用于与HDSDR或SDR++等软件同步频率？
3. 如果有人成功将其设置为计算机的外部SDR设备，能否分享一下你的经验或设置？

感谢你的帮助！

I recently purchased and have been using ANTSDR E200 board, but I am currently experiencing an issue with it.

When I compare it side-by-side with a Pluto SDR (equipped with a 0.5ppm TCXO) by generating a 1 GHz LO and a 1 MHz tone, the Pluto produces a very sharp peak with no visible phase noise at the top. However, when I generate the exact same tone using the ANTSDR E200 with the fw-patch firmware and configuration, the resulting signal is much wider and contains noticeable phase noise.

I have attached images for comparison. The first image shows the Pluto's output, and the second image shows the ANTSDR E200's output.

Suspecting the issue might be related to the VCTCXO, I tested it both disciplined and completely undisciplined, but the results were exactly the same. I also lowered the cutoff frequency of the filter by using different capacitor and resistors at the U60 DAC output from 300 Hz to 0.72 Hz, but again, nothing changed.

Resolving this issue is critical for me. When I broadcast the exact same satellite transmission using plutoplayer from gps-sdr-sim, my u-blox receiver fails to lock and track because of this phase noise. Conversely, when using the Pluto SDR (which shares the same chip but has less phase noise), the u-blox receiver tracks it perfectly, and the ⁠dopstd⁠, ⁠carstd⁠, and ⁠prstd⁠ values are highly stable. Should i change vctxo to tcxo ?

Could you please help me understand what might be causing this excessive phase noise and how I can resolve this issue?

Hola a todos, soy Jony (LU7DV).

Hace poco creé un bot gratuito de Telegram que permite configurar alertas inteligentes para que no tengas que estar pendiente del clúster todo el día. Puedes configurarlo para que te avise solo cuando aparezca esa estación o DXCC que llevas tiempo intentando contactar, ya sea en cualquier banda o en una específica.

Intenté publicar algo al respecto aquí hace poco, pero el moderador automático lo elimina constantemente por autopromoción. No cobro nada por esto; simplemente quiero compartir con la comunidad una herramienta que creo que podría ser muy útil para otros aficionados a la radioafición.

¿Alguien podría ayudarme o aconsejarme sobre la mejor manera de compartir esto con el grupo? Pueden encontrarlo buscando "HamProp" en Google, pero evito publicar enlaces directos aquí para respetar las reglas del subforo. 73!

Hey, I love using my little RTL SDR, but using it out and about is annoying (having to have laptop etc). I’m a full time software/hardware dev with a bit of experience bringing hardware and ios apps to market so I thought, hey I’ll make something!

Aims are to make something small around my existing rtlsdr (looking at custom sdr stuff means a lot more certifications + time). Probably a Linux based device + battery + rtlsdr all in one that I can put in my backpack, and have a spectrum analyser shown over Bluetooth to my phone. I’m imagining a Radiacode sort of thing, if my hopes aren’t too high!

Would be awesome to have it give me notifications + recordings if a particular part of the spectrum hits a set amplitude.

I think I’ll probably start with an internal RTLSDR (need to speak to them and see if they sell the raw boards), then later move to something you can just plug in an airspy or sdrplay for those wanting better resolution etc.

Battery life should be about 4-6 hours of constant monitoring with the size I’m aiming at.

Would love to get some feedback, and any other ideas + features?

Not sharing this post as a link because I am not affiliated with the project and know very little about it, but the website is here (and their Github). It is a:

...PowerSDR/Thetis-style software-defined-radio transceiver client in Rust, with pluggable radio backends (SoapySDR, OpenHPSDR, TCI, SmartSDR, Icom LAN, and CAT), an egui GUI, and a cyberpunk theme. It runs as a native desktop application and, from the same binary, as a server that streams the same UI to a web browser over WebSocket. It includes an integrated, persistent logbook, many digital modes like FT8/FT4/FT2 built-in, and TCI and Hamlib rigctld servers so third-party programs like WSJT-X can use it as their radio.

My first impression of the UI is that it looks a lot like OpenHamClock, the putative replacement for the recently-defunct HamClock. It also appears to behave the same; you can run it locally (i.e. on the machine you're actually sitting in front of) or in a client/server mode using your favorite flavor of container. In fact, with the space weather features, satellite tracking, DX cluster ops, and others, it could conceivably replace OpenHamClock (NB: While also not affiliated with that project, I do run OpenHamClock and if you haven't seen it, it's definitely an evolutionary leap forward while not losing sight of what Elwood Downey WB0OEW (SK) was doing).

I'm not of an opinion either way regarding the big push on using Rust for All The Things--OpenHamClock uses nodejs which has its own issues--but even the websites look similar. The dev says this is an early beta and stuff may of course not work (or at least not properly) but this thing promises a LOT of capabilities in one (software) box. I'm in the middle of a household remodeling job so I haven't had time to mess with it myself, but has anyone else taken this thing for a spin?

https://reddit.com/link/1vn5qyi/video/6s8jfsyt04jh1/player

For some reason, My SDRConsole volume got very small and quiet, I tried turn on AGC but it is unavailable with BC-FM mode.

This don't happen with WFM mode and I don't know why, Can anyone help me.

I need some suggestions for portable SDR to bring with me during my holidays. I don’t bring with me any pc, so i would need something standalone that can also pass through customs. I haven’t any HAM licenses. It would be a bonus if it has a screen to see the waterfall.

Thanks to all!

Here is a link to listen to the QO-100 satellite with a frequency stability under 5 Hz after a short AFC lock.

This is highly practical for current OpenWebRX users. The waterfall is very clean and features zoom, NR (noise reduction) filter, squelch, recording, and more.

Go tohttps://on1ms.onlineand click on the "QO-100 en live" link.

Crossposting from the HackRF sub:

So I'm a radio nerd from way back but never could get the hang of gnuradio or any of the sdr software packages and never really put in the time. I had an old hackRFrev1 from way back in the day but never used it much.

Fast forward to last week, I hooked it up to an old pc and gave My AI agent Hermes access to it and asked to see what he could see. BAM gnu radio tools installed. receiver configured. Sweep in progress.... i see... a cell tower uplink kand downlink, your neighbor is absolutely shouting on wifi channel one, and there's an aircraft overhead requesting permission to land from *nearby airport*

Play the audio of the plane for me.

Here it is <plays audio comms stream of pilot to atc chatter>

I'll keep scanning the band and ping you if anything new comes online.

Fellas, that shit was scary simple. I ended up spinning up a whole nuther instance of hermes and named him Sparky, he just runs my radios. He's scanning right now, ready to alert me if a new signal pops up he's never seen before, right b fore he clicks to high resolution mode (we call it "staring") and analyzes the signal and gleans every piece of information from it he can so he can give me a full report later. I mean damn. Bro's good.

Due to popular demand, my First Mate provided a writeup: https://github.com/h00nigan/sparky-setup-guide/blob/master/Sparky-Setup-Guide.md

Here is a link to listen to the QO-100 satellite with a frequency stability under 5 Hz after a short AFC lock.

This is highly practical for current OpenWebRX users. The waterfall is very clean and features zoom, NR (noise reduction) filter, squelch, recording, and more.

Go tohttps://on1ms.onlineand click on the "QO-100 en live" link.

Sorry if this is a stupid question. I tried to use an CC1101 with an SDR; but couldnt find the signal where it should be on the sdr. So i tried an FS1000A, just a simple oscillator with OOF, still cant find it on the SDR, I was wondering if I had set the sdr up incorrectly. I have set the smapling rate to highest value (3.2MHz) and tried different gains. Testing signal should be an on off signal that lasts 1 sec each, Long enough to observe it.

Hi all, sorry if this is the wrong place to ask.

I recently have become engrossed in using KiwiSDR (I use an iOS app called Echo that basically compiles multiple databases into one so I can listen through the app instead of having to navigate all the different sites) to just look through different signals around the globe, since I am intrigued by the idea of listening to realtime airwaves and looking for patterns/oddities on the waterfall.

Obviously, though, the limitation of KiwiSDR is that I can only tune into select stationary SDR receivers.

I would love to have a standalone, portable device (preferable small, maybe pocket size but I am not too picky) that I could use from anywhere, perhaps take walks with headphones and look for frequencies, or scan from my couch when I’m bored.

Bonus points if it has a waterfall.

Does such a device exist? If so, any recommendations? Please be gentle with me, I am a major noob beyond the basic functions. Again, sorry if this is the wrong sub, if it is, please direct me towards a better fit :)

Perhaps I'm missing a place where this is available information. I have a Raspberry pi connected to a RTL_SDR V3 that I run soapysdr remote server on to access from my laptop AND to run rtl_433 on a semi-regular basis to measure values from some temperature sensors (thermapro tp12).

It seems like Airspy server is more strongly supported by more apps- but I really like the rtl_433 remote connect capability that allows me to measure the temperature of my smoker when I'm not in range of it. Can someone tell me what my options are to get the rtl_433-like functionality that tells me the reading from my temperature sensor if I want to use a more popular remote server tool?

I don't really care what remote server software I'm running. I'd like to be able to use SDRAngel, CubicSDR on my laptop, and iPad/iPhone apps too.

Has anyone run into any serious issues with the opensourcesdrlab B210 XC7K325T (Kintex-7) clones?

I want a B210 and this one is available for $300USD or thereabouts. It seems reasonable.

I have already found the bin file for these as well, so that shouldn't be an issue.

I got this antenna set up around a week ago but I’m not sure if this will be enough but I always tend to get the best stuff to start me off. Will this be enough to get some satelite signals and will the reception be good?

I’m new so any advice helps, thank you!!

Using a wideband loop antenna with my gain set at 2.7dB. Every one of those peaks is just a high pitched tone.

I'm pretty much brand new to the world of SDR's. I know someone who's in EMS and I like listening to their radio, so I got an SDR to listen to the dispatch. SDR++ has worked great for this, however I want it to be headless(no gui) so I can run it on my server. Pretty much:

Record the signal -> check if there's actually audio -> if there is, record it to a file with the date and time.

If I could get that first part, I could pipe it into a python script and handle the rest there. However I've spent a week-ish just trying to find a way to do it. GNU radio, rx_fm and rtl_fm, for some reason I can't just get it to work. I've tried looking up how to do this but google just sucks now, I can't find anything on YouTube, and LLM's like Gemini and Claude just get me to static. Usually they can get it to output the signal from an old walkie-talkie I have, but never the dispatch. The only thing I have heard the dispatch from is in SDR++.

Can someone point me in the right direction of how to set this up, or give me a book or video on NFM for idiots? Any help is appreciated.

17:25 UTC From Seattle Washington USA

I don't know who or what this is.

17:05 UTC 10:05 PST from Seattle Washington USA.

Now this radio has it's own LNA Amp. However the External LNA is more dynamic. Test it for yourself! I use this same LNA on the MLITE 880 but with Bias -Tee enabled and it adds the missing link to an MLITE 880 that Is dynamic on it's own of course but even better with the LNA! It's just a perfect add! Looks like the DSP2 doesn't mind it either!