Little thing is capable of LRIT reception 😃

Hi all,

One of my SDR had a hardware limit/gap ranging from 380 to 404 MHz. So, if I use any up- or downconverter, will I be able to cover the missing gap? looking for suggestions from expertise. Thanks in advance.

Longbow: a desktop police/fire/EMS scanner for an RTL-SDR Blog V3 (It's all i have to test with) (Windows, receive only)

- Follows P25 Phase I trunked systems with voice, and scans analog channels. P25 Phase II coming soon.

- SDS200-style face: DIGITAL / ANALOG / ALL / OTHER presets, lists, avoids, hold, Simple and Detail screens

- Encrypted calls are marked and skipped

- Names unknown talkgroups from radio-ID clues; every call is logged

- TEXT screen: live call transcripts made on your own NVIDIA GPU, no cloud

- Waterfall that marks the control channel, the voice channels and every active call, with why each one is or isn't playing

- Aircraft map from its own ADS-B decoding on 1090 MHz: tracks, altitude, speed, type and registration, emergency and military alerts

- WEATHER button: NOAA Weather Radio, live NEXRAD radar, NWS alerts, on-air SAME alert decoding

- Workbench: listen anywhere from 24 to 1766 MHz in NFM, WFM, AM, SSB and CW, with recording

- Plugins for DTMF, two-tone pages and audio filters

- Phone and tablet control over your own private network; one-click installer with updates from the menu

Puzhi Electronics has released a pair of pin-compatible 4TX/4RX SDR platforms built around dual AD9361 transceivers and AMD Zynq UltraScale+ MPSoCs.

The P401D and P501D share the same RF section, connectors, PCB layout and software support. Users select the variant based on required FPGA logic and DSP capacity.

Shared Specifications

• RF: Dual AD9361, phase-coherent 4T4R MIMO
• Frequency range: 70 MHz – 6 GHz
• Instantaneous bandwidth: 200 kHz – 56 MHz
• Tx output: up to 22 dBm
• 0.1 ppm 40 MHz VCTCXO, external 10 MHz / PPS sync supported
• SPDT switches rated 9 kHz – 8 GHz
• Processing: 4×A53 u/1.3 GHz + 2×R5 u/533 MHz
• Memory: 2GB DDR4, 8GB eMMC, 256Mb QSPI Flash
• I/O: 40G QSFP, GigE, USB3.0, Mini DP, SSD slot, 40-pin expansion, GPS+Beidou timing
• Power: 12V 3A single supply, all external interfaces ESD protected
• Size: 160 × 150 mm

Variant Comparison

• P401D (XCZU4EV): 192K Logic Cells, 728 DSP Slices — good for general MIMO, spectrum monitoring, lighter DSP pipelines
• P501D (XCZU5EV): 256K Logic Cells, 1248 DSP Slices — extra DSP & BRAM for phased array, complex real-time processing

Software & Package

It works with common open-source SDR stacks and has partial compatibility with ADI FMCOMMS5 firmware. Standard kit includes metal enclosure, schematics, demo code and tutorials. Custom secondary development is available.

Applications: phased array radar, spectrum surveillance, GNSS receivers, UAV payloads, test & measurement, wireless algorithm research.

Note: the web demo uses simulated signals (no RF). Real scanning needs an RTL-SDR and the downloadable program

Earlier this week I shared information about a new SDR scanner, FalconSDR. Today instead of reading boring feature list you can just see how it works in your browser:

https://falconsdr.com/

You don't need to download anything or connect your RTL-SDR to test how it works. On this website you can control virtual RTL-SDR and listen to simulated transmissions and recordings on different radio bands.

If you like it and want to scan or record real transmissions with your RTL-SDR visit https://github.com/rafafunt/FalconSDR (project is free and open source) If you have any questions, feel free to ask in the comments. Program and demo are currently available in English and Polish language but you can ask for making other translation.

I don't want to spam in this subreddit so this is probably the last post about this project from me here. If you are interested watch it on github.

Southeast Michigan, Consumers Energy gas (DTE electric). New Itron 100G DLS ERT on an AC-250 (photo attached).

I've run rtlamr / rtlamr2mqtt with every message type, filtered and unfiltered, including a 24-hour capture, and gotten zero gas packets. My Neptune R900 water meter decodes fine on the same setup.

Has anyone in Consumers territory gotten their gas ERT to decode? Or is it encrypted or fixed-network only? Thanks!

"SDRangel has a step learning curve" - well, now you can ask Claude/ChatGPT to help, with version 8's MCP server.

From 2012 to 2016 I was a missileer at F.E. Warren AFB. I sat (and slept) 100 feet underground, ready to launch 10 Minuteman III nuclear missiles.

The orders would have come as an Emergency Action Message. I had no idea that the same messages go out in the clear on HF, or that people around the world have been logging them for decades.

So I built a site that listens and logs the messages with SDRs. Two KiwiSDRs feed it, the KPH receiver at Point Reyes and one in Iceland, both on 11175 USB.

When a message starts it’s recorded, a waterfall is captured, and speech-to-text transcribes it. That’s what the 30 characters (56HETY) are in the picture. The machine copy is usually rough, so anyone can correct it by ear. And you can listen live as well.

I'm trying to make the site as interactive and informative as possible, so if you have any ideas for that, please let me know.

Site: missileer.watch

The full story is in my r/shortwave post from Thursday: https://www.reddit.com/r/shortwave/s/A9mz70qF8l

Happy to answer any questions!

I use ADSB.im on RI 4 to feed ADS-B and AIS, everything works fine. I bought a third SDR dongle and antenna to play with ACARS / VDL2 / HFDL.

ACARS works and receives messages, but I noticed that the MLAT light was red and the web stats pages that I feed showed errors that it was not counting the MLAT.

I thought there was a bottleneck somewhere on the RP4, so I took a second RP4 just for ACARS only. I noticed that when it's set to ACARS only, I still have the on map blue ADS-B and green ACARS labels.

I think the ADS-B Feeder sees the planes twice and the MLAT twice, and it interferes with the MLAT calculation and sending data.

CPU usage -30% , RAM -1GB, and temps are fine, no undervolting. I'm using active USB hub for dongle. I don't see anything in the options that I could change.

I tried it on 2 RP 4 on official and beta ADS-B Feeder Image. How to set what to change to have 3 SDR for ADS-B, AIS and ACARS on 1 RP4 without problems with MLAT? I can use 2 RP4s but I prefer to have everything on 1.

Bonjour à tous,

Je partage un petit projet open-source que je viens de finaliser et packager : **RadioTranscribe-Store**.

### De quoi s'agit-il ?

L'idée était de fabriquer une sentinelle d'écoute autonome pour enregistrer et indexer passivement les actualités de la bande FM (sur France Inter par exemple), de manière 100 % locale, sans envoyer la moindre seconde d'audio dans le cloud.

### Comment ça tourne sous le capot ?

1. **Capture radio :** une simple clé logicielle USB (RTL-SDR) capte le flux FM via `rtl_fm` et `ffmpeg`.

2. **Préservation du matériel :** les flux audio temporaires sont écrits et traités directement en mémoire vive (`/dev/shm`), ce qui évite d'user les disques SSD en écriture continue H24.

3. **Transcription IA :** le modèle Faster-Whisper (`large-v3`) tourne en local sur processeur (quantification int8).

4. **Filtre anti-hallucination :** élimination des sous-titres fantômes récurrents de Whisper.

5. **Stockage hybride :**

   - Historique chronologique dans **MariaDB**.

   - Recherche sémantique vectorielle (RAG) dans **ChromaDB**.

On peut ensuite simplement poser des questions ou chercher des thèmes en langage naturel dans un terminal pour retrouver les extraits diffusés à l'antenne et leur date de passage.

Tout le projet (scripts, automatisation de l'installation et service systemd) est documenté ici :

https://github.com/TVIEIL/RadioTranscribe-Store

Si vous avez des remarques, des suggestions d'améliorations ou des questions sur l'intégration SDR/IA, je prends volontiers vos retours !

I'm a developer working on SDR software and trying to understand how people actually use their dongles before I build the wrong thing. Nothing to sell or sign up for, just reading answers.

If you have a minute, any of these:

1. What did you last use your SDR for, and what software did you use?
   
2. What part of that took longer or was more frustrating than it should have?
   
3. Is there something you tried to do and gave up on? What stopped you?
   
4. What's your setup (dongle, antenna, upconverter/filters, OS)?
   

Short answers are great. Rants are also great. Thanks!

NA4GJ

Come to think of it, I used to click on titles like that here, expecting to find inexpensive DIY projects or wildly imaginative ideas…?

You guys feel the same way, right?

Hi all, I'm a researcher at a university lab in Hong Kong, working on positioning with LEO satellites in cities. I'm looking for raw Starlink downlink recordings where buildings block part of the sky.

What would help most:

- An LNB/LNBF (or horn) + SDR (RTL-SDR, HackRF, USRP, etc.) recording the Ku-band downlink (~10.7–12.7 GHz)

- Receiver sitting still at ground level next to buildings, ideally a street with tall buildings on both sides

- Bonus: a second receiver on a nearby roof recording at the same time

- GPS or NTP-synced timestamps and a rough location (street-level is fine, no need for your address)

- 10–60 minutes is plenty

Already have old recordings sitting on a drive? Those count too, even if the blockage was accidental.

Not looking for dish app screenshots or speed tests this time, just the raw RF.

Anything used would be credited in the paper's acknowledgments (or however you'd like to be credited). Happy to answer questions about setup. Comment or DM me. Thanks!

Finally found out where we can look up radio frequencies in Canada, the TAFL search. Tried some hospital pager frequencies, but seem to also get City of Toronto water treatment plants... EFFL Effluent tank is full. Blurred the full email of the Toronto water department. Not sure where the zone humidity is from.

i asked DeepSeek to code me a ADS-B module for SDR++ alongside Claude Free Tier to improve things. and now we have ADS-B tracker built into SDR++ with waterfall

However. Its still very early stage right now. a lot of things are missing

im planning to ask these agents to add more trackers and decoders like AIS vessel tracker. and some more digital decoders and stuff idk about that.

*Update (Oct 24): The new screen arrived and everything's back on the kit. u/needmorejoules shared the ADS-B logic from his ADS-B Scope firmware, and it's now in P4 SDR. RTL-SDR.com article on it: https://www.rtl-sdr.com/portable-ads-b-receiver-firmware-for-the-esp32-p4-based-lilygo-t-display-p4-with-rtl-sdr/ His repo: https://github.com/jstockdale/T-Display-P4/tree/adsb Planes get single-frame positions with jump checks. On a 38-minute live run, positions updated in 86% of log rows, up from 69-76% before, with no jumps. Thank you, John! Audio, RDS and memories are next on the test bench.

I see I'm late to the P4 party, but this one uses the Waveshare ESP32-P4 dev kit (Pi footprint) and a generic 3.5" screen to make a cheap mobile RTL-SDR, with some Wi-Fi/Bluetooth fun on the side. You can get the firmware from the open repo, https://github.com/John-ODell/esp32-p4-rtl-sdr, or flash it straight from your browser on my website, https://www.northbridgelandmark.com/builds/esp32-p4-sdr/. The site also has a screen-only option if you just want the display working.

I'm going to keep adding to this until I run out of room on the flash. Unfortunately the touch on my screen stopped working, so a new one is coming this weekend. Here are some details and pics. I'd love some feedback and ideas. This is my first time posting, thanks!

**Hardware**

- Waveshare ESP32-P4-Module-DEV-KIT (Raspberry Pi footprint)

- MHS-3.5inch Display-IPS: a generic 3.5" 480×320 SPI resistive touchscreen made for the Raspberry Pi

- RTL-SDR Blog V4, plugged straight into the kit's USB-A port

No PC or Pi in the loop. The P4 runs the USB stream, the FFT and the drawing, and the ESP32-C6 on the kit handles Wi-Fi and Bluetooth.

**What works now (v1.1.0, tested on the kit)**

- Spectrum and waterfall at about 10 fps, with tap-to-tune, gain/AGC, range, zoom and band presets

- ADS-B with an aircraft list and an offline map from the SD card. On a 44-minute run with logging on it sat at 22% load with zero dropped samples

- Wi-Fi scanner: a network list and a channel view that draws each access point as a curve at its signal strength (see the screenshot)

- BLE scanner for nearby devices

- CSV logs of aircraft, Wi-Fi and BLE to the SD card

- Four looks (Studio, PortaPack, Phosphor, Vintage), with big keys made for a resistive screen. A fifth, Neon, is in the next build

**Built, testing this weekend when the new screen arrives**

- Speaker audio through the kit's ES8311 codec: WFM, NFM and AM, with squelch

- RDS station names on FM

- 8 channel memories and a memory scanner

- Portrait mode with the USB ports facing up

- An animated boot splash

Prebuilt images for both P4 chip revisions (1.x and 3.x) are on the releases page. GPL-3.0.

The screenshots come from the repo's preview tool with made-up networks and planes, so nobody's real SSIDs or location are shown.

Big thanks to OrcSDR, LakeShark and xtrsdr for showing the P4 could do this.

What would you want next: POCSAG pagers, AIS/APRS, an rtl_433-style sensor decoder, or rtl_tcp over Wi-Fi?

VUURWERK v1.5.1 is out. New: PATROL, a hands-free voice hunt. In the spectrum's VOX mode press 2 and 8 to set a range and 0 to start; the radio walks the band, stops on voices, moves on when they finish, and PTT locks the one you want. Plus a big fix pass: no more keying up when you leave the spectrum with PTT held, no freeze on a flat battery, F+9 and the tone scan no longer disturb your repeater setup, and the main screen refreshes properly. Settings survive the upgrade. UV-K5 V1 only.

https://github.com/Tokeloshe/vuurwerk-firmware/releases/latest/download/vuurwerk-v1.5.1.packed.bin

KC3TFZ 73

Hello, I am a SWL and I am closely interested in the world of SDR. I would like to participate with my station in the APRS network. I have an RTL-SDR Blog V4 and I managed to configure Direwolf to appear as a beacon on APRS-FI. The website displays me properly on the map, and I can see my station details.

If I understand correctly, every 30 minutes my station sends a position update to the site for my GPS location (which I provided in the direwolf.conf file).

On the other hand, while I can see all the stations my station has heard under the Info section, I feel like there are very few compared to the actual frames received.

Also, according to the data, the stations I receive are only about 40 km away (even though in reality I receive them from much further away). Why doesn't APRS-FI show them? (Filter issue? Incorrect setting?)

And finally, I notice that very few frames per hour are sent to the network (even though once again, my Direwolf window constantly displays incoming receptions).

Thank you very much, and sorry for this very (too) long post.

73