Hey everyone I found one on Lab401 eshop for 300$ I think but I wanted to seek help before I buy it, can you recommend better one or one you used to buy it? Because There is so many eshops and providers but I dont wanna get scammed or to buy one that is not worth the money. Thank you . Also would be nice that it can be shipped in Europe
Hi all, hope this is allowed here as I am new about.
I recently moved into a new property, far from the city and - I thought - ideally located for getting back into radio. So I spent the weekend hoisting up and tuning a wire dipole centred on 14.175MHz/20m band. I got it up high in the trees by the house, aimed it at a heading I thought would be interesting, and tonight I finally hooked up the gear. I was excited to have a poke around the spectrum, free from interference and metropolitan noise.
Instead, the whole of the amateur band and a good portion of spectrum around it was basically flooded with this weird signal, which looks like it is from a single source but with (harmonics?) right though the band spaced every 4kHz or so. (see screenshot attached).
What in the heck is this and how is it allowed to make such a mess of the spectrum? or is it me? I have verified it is there on the HackRF, as well as on my TinySA and I can hear it on several radios too. It is weirdly inconsistent.
I'd appreciate any input from you guys... I have a baseband recording too of a couple of minutes of this, can send to anyone interested but it's about 1.2GB.
FYI - I'm located in South Australia, about 50km from the city.
Just realized I forgot to make a separate post after having set this up. I did update my post about my WAP gateway to include this info, but I figured I’d make a standalone post to ensure that more people can find this info.
This HTTP proxy is only necessary for those of you who are using CDMA phones on 1xBTS.
Needless to say, although I take as many security precautions as I can, I cannot make any guarantees! So please avoid transferring sensitive data over it, just to be extra safe. For anyone wondering, it’s located in Germany.
Proxy IP: 176.103.221.33
Proxy Port: 3128
Please do not try to use this for any other purpose besides normal web browsing on vintage phones that require a proxy. Your IP address will be automatically banned if abnormal activity is detected.
As the question says.
I can get network connection fine on a laptop using SDR++.
But I cannot get RF Analyser or SDRtouch on Android to connect to an available Pi running Spyserver.
Whenever I try to connect with the apps, they say connection unavailable.
Any ideas where to start to look into the issue, or even an alternate app to try?
Hey everyone,
I want to share a project I’ve been building for the community called GopherTrunk (GopherTrunk.org). It is a software-defined-radio scanner designed to follow digital trunked-radio voice calls and decode them directly to audio.
I wanted to create something incredibly easy to deploy, so the entire engine is written natively in Go. This allows it to ship as a single ~10 MB static binary for Linux, macOS, and Windows without any C dependencies (no librtlsdr or libusb required). It is built to run entirely on a pool of cheap RTL-SDR dongles.
Key Features:
Where I need your help: Every trunked control modulation listed above currently has an end-to-end IQ-to-Control-Channel chain shipping. However, I need folks to throw real-world RF at it! I am actively looking for testers to run real-air captures so I can dial in the vocoder level calibrations and validate the on-air FEC layers.
If you want to test it out, you can grab the prebuilt binaries (including a Windows installer) here: https://gophertrunk.org/downloads.html
Check out the GitHub repo for the full documentation and architecture breakdown. Let me know what you think, what breaks, and what features you'd like to see next!
Shipped to the USA in about a week and a half. Way heavier than I thought. Feels high quality, higher quality than I expected, works just fine with original firmware (as well as really old UHD 3.x firmware, unlike the LibreSDR clone), overall it performs great.
I’ve been working on this project for a while. I am building two triaxial fluxgate magnetometer arrays to measure everything from DC to lower LF frequencies up to around 47kHz. I’m currently in the middle of the first half of building, which is mainly focusing on the hardware and firmware involved with capturing the data. Soon I’ll start on the second half, which is to turn the data output of my setup into a panoramic image of the electromagnetic environment across my frequency range. As of now my goal is to finish building everything. I would also like to clarify that so far this has just been me working on this, and I’ve been working on it for several months now.
I’ve also been pretty specific with my choice of equipment. Six DRV425EVM fluxgate magnetometers, which have a frequency range of DC to 47kHz. I’ve already set up two sensors to capture stereo data and I’m currently waiting on the mounting frame before I start working on all six. Every channel has 24-bit simultaneous sampling using an AD7768 evaluation board, which has been outfitted with an ADR4525 voltage reference, C0G capacitors, metal film resistors, a high PSRR LDO, and single point grounding to reduce noise. The sampling rate is not set yet but would probably be at the upper limit of what this ADC can do, which is around 250kSPS.
Signal processing would take place on a Teensy 4.1, or possibly a different computer based on the computational demands of the onboard processing portion. The signal would be split up into many simultaneous frequency bands. As for the specific type of filter, I’m using a CIC filter paired with a FIR compensation filter, which fellow Reddit user underwilder correctly recommended:
“As far as your sample rate conversion, you would need a cascaded Integrator-Comb filter paired with a high-order Finite Impulse Response compensation filter to sharply cut off all frequencies above the new Nyquist limit before dropping the sample rate.”
I use this to split the frequency spectrum into many different bands, each with its own sampling rate scaled to three times the highest frequency in that band. This variable sampling rate approach serves two purposes, it reduces the data rate significantly compared to transmitting everything at full rate, and it maximizes averaging gain in each band, which directly improves sensitivity and lowers the effective noise floor. Here’s the full band list:
46-47 kHz — 141 kSPS
45-46 kHz — 138 kSPS
44-45 kHz — 135 kSPS
43-44 kHz — 132 kSPS
42-43 kHz — 129 kSPS
41-42 kHz — 126 kSPS
40-41 kHz — 123 kSPS
39-40 kHz — 120 kSPS
38-39 kHz — 117 kSPS
37-38 kHz — 114 kSPS
36-37 kHz — 111 kSPS
35-36 kHz — 108 kSPS
34-35 kHz — 105 kSPS
33-34 kHz — 102 kSPS
32-33 kHz — 99 kSPS
31-32 kHz — 96 kSPS
30-31 kHz — 93 kSPS
29-30 kHz — 90 kSPS
28-29 kHz — 87 kSPS
27-28 kHz — 84 kSPS
26-27 kHz — 81 kSPS
25-26 kHz — 78 kSPS
24-25 kHz — 75 kSPS
23-24 kHz — 72 kSPS
22-23 kHz — 69 kSPS
21-22 kHz — 66 kSPS
20-21 kHz — 63 kSPS
19-20 kHz — 60 kSPS
18-19 kHz — 57 kSPS
17-18 kHz — 54 kSPS
16-17 kHz — 51 kSPS
15-16 kHz — 48 kSPS
14-15 kHz — 45 kSPS
13-14 kHz — 42 kSPS
12-13 kHz — 39 kSPS
11-12 kHz — 36 kSPS
10-11 kHz — 33 kSPS
9-10 kHz — 30 kSPS
8-9 kHz — 27 kSPS
7-8 kHz — 24 kSPS
6-7 kHz — 21 kSPS
5-6 kHz — 18 kSPS
4-5 kHz — 15 kSPS
3-4 kHz — 12 kSPS
2-3 kHz — 9 kSPS
1-2 kHz — 6 kSPS
1kHz-100Hz — 3 kSPS
100-10Hz — 300 SPS
10-1Hz — 30 SPS
1-0.5Hz — 1.5 SPS
0.5-0.1Hz — 1.5 SPS
0.1-0.01Hz — 0.3 SPS
0.01-0Hz — 0.03 SPS
For the upper VLF range I implement onboard FFT and decimate the frames to around 2000 FPS after the FFT has been computed. This process of oversampling and decimation is applied across all bands rather than simple downsampling. This is done to lower the noise floor and strengthen sensitivity during processing. The oversampling and coherent averaging approach allows the effective noise floor to be pushed well below the raw sensor specification of 1.5 nT/√Hz, with the lower frequency bands benefiting from averaging ratios in the tens of thousands to one.
A GPS and IMU are also implemented. The data from those feeds into a dual layer drift correction system I developed, which I’ve documented here:
“This document serves as a dated record of an original concept developed independently by me. The method uses a multi-channel directional magnetometer array to capture electromagnetic signals across the DC to VLF frequency range. To correct for platform movement and rotational drift, the system uses two complementary mechanisms: an IMU for rapid high-frequency motion correction, and the captured signal imagery itself as an attitude reference, using stable natural electromagnetic sources in the environment to detect and correct slow rotational drift in software. This dual correction approach allows accurate directional signal imaging from a mobile platform without fixed reference points. Conceived and developed independently as part of a personal scientific project. Date: May 8, 2026.”
This idea is older but the day I formally wrote it down was May 8th.
Right now my main goal is getting six channels of usable directional data from the magnetometers. I’m hoping that by the end of the year, possibly earlier, I can start working on turning the data into a panoramic live video.
I’m sure I’ve left some things out, let me know what you think. If you have experience with any of the components or any of the many processes I’m using, I’d love to hear what more experienced people have to say.
[ Removed by Reddit on account of violating the content policy. ]
I have to present a power point explaining “why sales?” “Why this company?”, “why me?” I don’t want my PowerPoint to be too boring but I don’t want to make it too humorous either.
What’re some ways you recommend I keep the panel engaged, should I include images or what?
Does anyone here on r/hackrf own the openSourceSDRLab PortaRF. I am am looking for an opinion of someone who has used for a while. Everything I find is comments on the prerelease version.
Thanks,
Hey everyone,
I wanted to share a custom firmware project I've been working on. While contributing to the main PortaPack Mayhem firmware, I wanted to experiment with a build dedicated entirely to RTL433. The result is Porta-433.
It’s an early alpha release, but it kinda works and I’m ready to get some feedback on it!
What is it? Porta-433 is a stripped-down custom firmware for the PortaPack platform. It’s built on the Mayhem foundation, but I intentionally removed most of the standard Mayhem applications to keep it lightweight and focused squarely on parsing and decoding supported RTL433 signals right on the device.
Key Details:
Known Limitations (It is an Alpha!) Please keep in mind that this is highly experimental and actively changing. RTL433 was originally designed to run on a PC, so squeezing it into the PortaPack comes with constraints. Because of the limited memory and computing power, it might drop valid samples or only catch the nth repetition of a signal. Furthermore, fitting all the RTL433 data onto the small PortaPack screen is a tight squeeze.
A huge thank you to the Mayhem, RTL433, and HackRF teams and contributors—this wouldn't be possible without their work.
You can check out the details and grab the code from the repo here: https://github.com/htotoo/porta-433
You can go to the releases part, download the ppfw.tar, and flash.
PRs are welcome! (Note: If your change is a general firmware fix and not specifically related to RTL433, please submit it upstream to the main Mayhem project).
Use it at your own risk, but let me know what you think!
Hey everyone,
I’m looking to get back into capturing weather satellites and could use some advice on putting together a reliable kit list for the modern birds.
I used to pull images from NOAA 18 and 19 back in the day, but I want to look into the newer satellites now. Currently, I only have an RTL-SDR V4, so I’m starting relatively fresh on the antenna side.
A few specific questions I have:
Any recommendations on gear, specific antennas, or software to get an automated setup running would be hugely appreciated!
Thanks in advance!
I’m actively looking to get out of sales in general, especially the BDR/SDR roles. It’s not fulfilling, it’s dull, repetitive, and isn’t something I see myself doing long term, even eventually into an AE role. Pressured and unnecessary stresses that come with it isn’t something I care for anymore.
I’m a little lost on what else I want to pivot into. If you are/were in the same boat as me and made your exit, what did you go into and what suggestions would you have for me on what careers I could pivot to?
Hi All,
I have designed and built a compact bandpass filter for the 915MHz ISM band,aimed at reducing out-of-band interference in LoRa/SDR/ISM/IoT front-end applications.I'm looking for feedback from other rf design engineers on whether the measured performance and layout look reasonable.
I'm mainly trying to validate the design and understand if there are any obvious improvements before I iterate further.
Design Overview
Type: Bandpass filter module with integrated u.fl rf connectors
Centre Frequency: 915MHz (26MHz wide)
System Impedance: 50 ohms
Intended use: ISM/LoRa/SDR front-end/IoT gateway filtering/Lab interference suppression
PCB Size: 10mm by 12mm by 2.4mm (footprint) including the u.fl rf connectors
Measured Results
See plots of narrowband and wideband S21(db) filter performance below:
Measurements where made on a VNA using a SOLT calibration.
Physical Implementation
PCB: FR4 (4Layers)
Size: 10mm by 12mm
RF Connectors: u.fl
Full 2-port S-Parameters are available for this filter module covering the frequency range (100MHz-6.1GHz).
Finally,find attached photos of the RF Filter-the 2nd photo compares the size of the RF Filter to a standard SD-Memory card.
I love the SDR world and want to become an avid user. Receivers are always improving and the applications are endless! Whether scanning trunked P25 radio systems or listening to shortwave broadcasts from around the world, SDRs are a welcome addition to any station.
My issue is that I transmit on various radio services and I’m always afraid that my transmissions will damage the front end of my SDRs, which leads me to not using SDRs as much as I’d like.
I have an sdrplay duo, rtl-sdr and I’d like to buy a kraken sdr, but these devices (not all at once) would be used in my vehicle, and antennas would all be less than five feet from transmit antennas transmitting with anywhere between 25 and 125 watts on frequencies between 1.6MHz and 520MHz.
I don’t want to damage the SDR(s), but I need to be able to transmit near them. I’ve thought about trying to design an “antenna shunt interlock” system, where if any radio transmits, the receiver inputs are shorted to ground during transmit. I have some Teledyne SMA coax switches (and some shorting sma caps) and could potentially get this up and running…
Do I need to do this? Are SDRs robust enough to take the abuse? Are some SDRs more forgiving than others? Can the kraken withstand one of its five antennas being about a foot from a HF antenna transmitting at 125w?
Any insight on how to best avoid damage to SDR receivers while in close proximity to transmitters would be greatly appreciated!!
Can I realistically move from warehouse work into an SDR role?
I currently work in a warehouse job where performance is KPI/target based, and I’m interested in breaking into tech sales as an SDR/BDR.
I’m in my early 20s, don’t have a strong educational background, and have no direct sales experience yet.
What would be the best path to land an entry-level SDR role, and what skills should I focus on first?
