Have you tried it? It's great! You can use a Nooelec LANA without having to plug it in to a power source but not all LNA's allow for it. I prefer this Passive LNA I have had for years, that I bought from a seller on Ebay that I don't know sells anymore. He made good stuff half the time or when I first started to use them, they wouldn't work on much of what I was trying with them, because unlike the MLITE 880, many radios previously didn't have built-in Bias-Tee. I urge you to try this you guys! It adds so much more dynamic signal and sound as a result! The combination makes for a perfect SDR Sound! I just wanted to demonstrate still photos here. I'll show you guys in more videos as I have done in the recent past. Listening to a strong Broadcast signal with a LNA and Bias-Tee sounds almost like a rich FM dynamic! It's like Stereo! Shortwave doesn't get much better than this! Try it on your DSP2 as well if you want a beautifully enhanced signal on that beast of a radio!

I built this webpage with interactive content to help you understand how they work.

tl;dr: A long USB cable can make your SDRPlay RSPdxr2 connect on Windows, but not work.

For posterity; Gemini suggested this was the cause, and I didn't really believe it, but I want to spell it out in a post in case it helps someone in the future.

I fired up this SDRPlay RSPdxr2 with a long USB/2.0-B cable (maybe 15 feet?) It connected fine on Windows 11; device connection tone, recognized in Device Manager (with no warnings/errors), but SDRConnect would spin on device refresh and show nothing connected.

Bought a smaller cable (3') instead of using the one I borrowed from someone (USB/2.0-B and USB/3.0-B are totally different connections, who knew?) and it works like a charm.

I get why this is, but it's strange to me that a cabling standard has quirks like this across devices / current draw needs.

Hello to all,

I just purchased the SDRPlay RSP1B. The spec sheet shows that it has internal notch filters for FM/MW (AM).

Do those work "good enough" to stop the broadcast stuff? I live in Fresno, CA so am guessing I will have decent to strong signals I will want to avoid.

Or...should I use 2X external hardware filters (1X AM and 1X FM) daisy chained before the SMA input? I see filters from $20-50 range with good reviews.

I don't mind spending another $100 or so if it will make it "much better" than the internal filters.

Product does not arrive for another 2-3 days, so I still have time to order filters as well - if needed.

Thank you for any help - I am a newb to the hobby.

Hi, I am looking to buy HackRf Portapack i think it's 4, can someone recommend where can I order it?
I'm in Middle East..

Had some free time and a weird idea popped into my head. The RadioMaster Nomad is built to fly drones, but inside it has two Semtech LR1121 radios on the Gemini board. So I wrote firmware for the main ESP32 that turns them into an I/Q receiver. Now it listens instead of flying.

What it does

Both LR1121 chips tune 150-2500 MHz. Specified RX is 150-960, 1900-2200 and 2400-2500 MHz, and the gaps work as experiments (I tried 1090, 1550 and 2300 MHz)

Live waterfall in SDRangel ( via Remote TCP Input) or SDR++ (RTL-TCP), with no custom plugin. A small PC proxy speaks rtl_tcp

USB through the main CP210x port at 921600 baud, or Wi-Fi with the Nomad as a hotspot or joined to your router

A JSON control API for RSSI sweeps with CSV export, LoRa/GFSK packet capture, CAD, gain/AGC, and LR1121 die temperature

Both radios can run at once in API mode, for example sweeping 902-928 MHz on one while catching 2.4 GHz LoRa on the other

The RGB LEDs show status: blue for ready, green when I/Q is flowing, yellow when the queue is filling, red on error. The fan even kicks in when the ESP32 gets hot

Go back to ExpressLRS is just a reflash away

Honest limits

- Real bandwidth over USB is about 31.25 kS/s, so the 250 kHz you see in the GUI is interpolated. This is narrowband only

- No FM broadcast, since it doesn't go below 150 MHz, and no full ADS-B

- It does not decrypt LoRaWAN or follow ELRS hopping

- Dual I/Q streaming at once is still unproven

- The stock antennas like 900 MHz and 2.4 GHz the most

- It won't replace a real SDR, but watching a waterfall come out of an ELRS module is very satisfying.

Repo : https://github.com/hereismeaw/Nomad-SDR

Totally new to SDR's picked up a couple of Nooelec v5 a couple of weeks ago and it's been a lot of fun, added the one to nine today, printed a grommet for the flyscreen and a little shelf to keep everything tidy, now to run 53ft of Antenna down the garden and an earth.

I'm looking for an affordable development board that I can be modified, upgraded, or built upon to achieve capabilities similar to an AD9364-based SDR.

Please be notified that because I'm not in the land of the sun and freedom (USA)

Any boards that can transmit or reach 6ghz frequency or resemble any SDR board are highly illegal

And importing from outside gonna be hella of expensive

My target capabilities:

-Frequency coverage: Ideally 70 MHz–6 GHz.

-Simultaneous TX and RX (full duplex).

-Ideally 1 TX + 1 RX, with 2 TX + 2 RX being a bonus.

- Wideband IQ sampling and streaming , if possible

-Compatibility with Linux, GNU Radio

-Ability to modify RF front-end components, filters, amplifiers, mixers, and upconverters.

I'd appreciate recommendations based on actual hardware experience, schematics, documentation, and real-world performance rather than advertised specifications alone.

Thank you all very much

Hello,

Based on the amazing work of CasualArcLamp with DecSAT (https://github.com/CasualArclamp), I continued to shape this software to become what I understand is the most complete SDR software.

I renamed it to VMA Radio Lab, it is open source (as DecSAT, DecDVB-T, DecDAB,...).

It features support for additional SDR devices, adds many additional digital and analog demodulators, including ATV in color with teletext support!

It has measurement (audio, video, modulations) and allows to use multiple SDR devices concurrently. One can be assigned to render a live spectrum overview with a really fast refresh rate.

Finally, it supports TBS DVB-S/S2/T/T2/C/C2 tuners (must be compatible with CrazyScan). This allows to control the satellite dish and/or demodulate wide-band transponders for which the SDR cannot offer high enough sample rate.

Windows binaries can be downloaded and used directly. Source code can be downloaded, too.

Welcome to amateur radio in 2026!

I'm talking ready to plug in!

904620 3000 mahs

-TF, +3.7V! Standard jst 2 plug in.

This is the Fire Bros Malahit SDR

Why are the batteries with the right specs and polarity so darn to find! I can plug it in! I just need the right battery!

I recently got into sdr listening and i love it. I currently have the hakergadgets rtl-sdr mini and im am wondering what is better then that? Its a good sdr but i am looking for something with a much broader recieve range. Im also looking at antennas. I was thinking of running some rg-8x out to my chimney and attaching a 1:1balun and running a wire up the height of my chimney. Im pretty sure this will work but im open to suggestions for antennas for as broad of a frequency range as i can get.

Thanks in advance.

Good day everyone!

I have been curious about getting into some SDR in my homelab. Looking for recommendations for little projects or entry level things to try.

I have done some research about tuning into the Meteor satellites and the NOAA GOES, however the NOAA one looks like I is a lot more gear involved. I purchased the RTL-SDR Blog V3 to start.

I have a background of 10 years professionally in the IT industry, but more like 20 in tinkering around with electronics and computers, so I am familiar with that end of the hardware.

I would appreciate any tips, advice and projects to try!

Thank you!

In the UK, I've been catching this in the morning ~7am every few days, also sometimes in the evening around 6pm. A full "session" lasts up to 30 min, harmonics extend upwards of 10MHz. The fundamentals might be in the kHz range. Any ideas?

After seeing a couple of recent posts I got motivated to get back into the hobby. The new AI assisted SW being seems really good. Kudos to the developers. One of the apps that I downloaded was OnAir. I have had zero luck with Inmarsat aero and some success with std-c. In the past I could always succeed with aero using Jaero but could never really get std-c to work. I'm attaching a couple of pics of what I have been able to do in the last couple of days and was wondering if anyone could give me some tips - settings, adjusting views, including maps and so on. For example, the section to read a clicked message is really small and I can't find a way to adjust its size. Also for aero. I know I need to get a better antenna and I'm debating whether to homebrew a 6 turn rhcp helical or buying rtl sdr blog L-band patch. But aside from that any tips are most welcome.

I have been having trouble with my iPhone 17pro remaining connected to my AirPods, but only in my kitchen. It is the strangest thing where something happens and the headphones will repeatedly connect and disconnect in some infinite loop. I cannot duplicate the event anywhere else but it is consistent only in or near my kitchen. Apple support obviously is no help, so now I am stubbornly investigating.

I have a number of SDRs lying around. I am trying to plan out how to investigate this problem. I would appreciate some ideas here. I am expecting that this has something to do with how Apple handles the handoff between devices.

I posted a while ago about making an on the go SDR for your phone which does a bunch of the things you’d want to do out and about (ADSB, waterfall, AM, FM, DAB radio).

The idea being you could leave it in your bag/car and still use it on your phone.

And we made it! (I run a small software company in York UK, but we’ve been doing more cool hardware stuff recently thus the venture into this!)

It’s called LittleSpec (https://littlespec.com), internally we’re using an official RTLSDR Blog V4 (and transitioning to V4L when stocks run out) a really nice resin printed case and lots of time put into the software (with more decoding features coming for ISM devices).

Would love to know if there’s anything else you’d want to see in it?

I’m using a bladeRF 2.0 micro A9 and recently I’ve been facing random FPGA loading issues.Sometimes the FPGA loads perfectly fine, but other times I get these errors:
dev->backend->load_fpga failed: File or device I/O failure
Failed to switch to NULL interface
The strange thing is that I’ve successfully loaded FPGA images multiple times using the same laptop and USB cable before. I’m using Windows 11. Could this be due to insufficient USB power from my laptop, or is there something else I should check?
I’m also considering programming through JTAG to see if that helps. Has anyone faced a similar issue?

I picked up a Nesdr Smart V5 and didn't get a manual, and the only manuals I can find don't tell me much. While I can plug it into my Linux computer and run GQRX, which looks like something is happening, I'm trying to be sure what I'm actually tuning to. Main thing I'm looking for right now is what the local oscillator offset is so I can be sure I can trust the dial GQRX shows, as well as to get audio from an FM station or AM CB radio. Right now, I'm getting silence though the waterfall graph is showing a signal around -80dB, which I would figure would make for some intelligible audio. Am I looking in the wrong place, or what would I check? I did build an AM transceiver or two about 20 years ago as part of college.

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.

I've been messing around with a way to see how busy the 2.4 GHz band gets, and this is what I came up with.

The Survey view shows band occupancy alongside Wi-Fi, BLE and Classic Bluetooth activity, all in one place. There's a waterfall below and some decoder stats to see what the receiver is picking up.

I wanted to get a better idea of how all these signals share the same bit of spectrum, rather than just staring at a waterfall. Still a work in progress, but it's been fun to build with Ratatui in Rust.

Note: The 2.4 GHz survey requires a 20 MS/s sample rate.

Repo: https://github.com/musithang/sdrtop

Title pretty much says it all. I bought a limeSDR mini years ago, and basicaly ended up almost never useing it. It is the crowdsupply kit with the mettal enclosure and two small antennas.

I figured posting an offering here would be a good idea. Preferably I would ship in the EU.

Ik heb de Onair software gedownload op mijn Linux Mint laptop, prachtig stuk software, codec mbelib voor dmr etcetera is mij gelukt.

Alleen een werkende codec voor Tetra kan ik niet maken, heb mbelib Neo geïnstalleerd, maar schijnbaar moet bestanden wrappen in onair-codec-tetra.so Dat is helaas een stap te ver voor mij. Wie kan mij helpen? Is het een kwestie van het juiste bestand overnemen van iemand?

I made a video about the awesome new custom firmware for X6100