Сегодня смотрел страничку офиц. диллера на алиэкспресс и увидел что blog v3 раскупили...

Поставки еще будут?

just do it。。。。

Hello friends, got into tracking flights recently with SDR, and I find coverage to be weak despite living at a height because of the roof.

What's the best antennas available in India right now, or is it better to build our own antenna?

So total SDR noob, obviously. Been trying to get an image from Meteor satellites as my foray into the hobby.

I bought a Nooelec RTL2832U. I made a V-dipole antenna. The metal legs are made of brass, about 22 inches long, 1/8 inch thick, and 120 degrees apart.

I tried to get a signal in SatDump. Used Gpredict and cross referenced it with n2yo.com to confirm it was actually accurate.

Long story short, I've had two good passes where Meteor M2-3 and M2-4 were about 80 degree elevation. Saw nothing on the spectrum.

So I tried testing continuity on all my antenna connections, confirmed everything is clean with no resistance.

I tried just using SDR++ and picking up some FM radio signals, seems to work fine just to prove my setup can pickup something. And As expected, the signal gets much worse when I disconnect the antenna. Doesn't prove mush but antenna does something. Not sure what else my problem could be.

I attached a few images. The first shows my spectrum blank during a Meteor M2-3 81 degree pass. Images 2 through 4 just show my setup. Images 5 and 6 show my settings in SatDump. Thanks

Hey everyone. I recently got around to listening to the aether in the best place possible for me. I use the V4 for listening. One day, I went for night-hits in the HF (or shortwave) bands, and at the 40m Amateur radio band (as stated, 7p195p000, modulated LSB) and I found a great gem. I need to link it, so listen to the link, it's great, the fun starts at around a minute or so. Some guy jamming others. Like some say "Absolute Cinema". The other guys are barely audible because of the noise, but DAMN!

So i am a complete noob and have some questions.

As far as i understand the optimal antenna needs to have a length of λ/2 or λ/4. Do i need to have special antennas for each frequency that I want to listen to, or how does it work?

Also, i know that when transmitting with the wrong antenna you can damage your transmitter. Is there the same issue with receiving?

In short: which antenna do want as a beginner?

Around 14-15-41_03-09-2026 UTC

RTL SDR V4, V dipole 16cm antenna, TQP3M9037-LNA (those cheap yellowish LNAs)

Yes the tune is really cut off (at least from my reception) rather than abrupt video cut.

Hello I'm working on the following project

I want to sample all 50msps from the fobos in the vhf range to then record some channels which we are using ourselves for documentation reasons.

I tried with soapysdr but it just allows 32float to Sample the IQ Data which I think might be the Problem. Cause I get in trouble with demodulation with csdr and the architecture of my Linux System.

The fobos either way has only a 14bit ADC so I guess 16 bit might be enough.

Has anyone tried Something Like this and If so, which api are you using to connect with the Fobos SDR?

Thanks, If anyone knows anything let me know.

Cheers!

P.S. I wrote the Software by myself and it already did Work with an airspy R2 with 10MSPS.

Just wanted to Upgrade..

I have some more info at https://saveitforparts.com/2024/11/12/resources-for-satellite-experimenters-hackers/ although some of it is a bit outdated!

Hi everyone,

I’m a computer science student, and SkyAero originally started as a university course project. I wanted to continue developing the idea as a real Android application, so I kept working on it in my spare time after the course ended. It has now become a long-term personal project.

SkyAero connects to an RTL-SDR/RTL2832U receiver through USB OTG and decodes 1090 MHz ADS-B and Mode-S locally on the Android device, without using an internet aircraft feed.

A connected receiver can be assigned to either ADS-B reception or the 118–137 MHz AM air band.

The ADS-B side currently includes:

• A live aircraft map with configurable labels, trails and online or offline maps
• Aircraft and traffic lists with registration and type information
• ARC and ROSE Navigation Displays with TCAS-style traffic
• An offline terrain layer made from NOAA GLOBE elevation data
• A Primary Flight Display for a selected aircraft
• A combined PFD/ND landscape view
• An augmented-reality view using the phone camera

I also added Mode-S Comm-B decoding. Its availability depends on the region and nearby radar coverage, but when these replies are present, SkyAero can receive IAS, TAS, Mach, magnetic heading, roll, selected altitude and heading, QNH and static air temperature. It also derives wind from the aircraft’s air and ground vectors using a built-in World Magnetic Model.

The VHF receiver has a numeric keypad for entering frequencies directly, 1 kHz, 8.33 kHz and 25 kHz channel handling, a live spectrum, signal meter, squelch, volume and mute controls, manual or automatic tuner gain, PPM correction and named frequency memories with favourites. Reception can continue in the background.

The cockpit displays are experimental hobby visualisations, not certified flight instruments. The application is receive-only and does not transmit.

SkyAero requires an RTL-SDR receiver, a USB OTG connection, a suitable antenna and the free Android RTL-SDR Driver application.

It is now available on Google Play:

SkyAero: ADS-B & Air Band SDR

The 24-hour trial only starts when real SDR data is first received. After that, it is a €5.99 one-time purchase, with no subscription.

Hi everyone,

I'm building an OFDM transmitter and receiver from scratch in GNU Radio as a breakdown/learning exercise. The TX side is working, and I'm now trying to build the RX chain block-by-block instead of using the complete OFDM Receiver block.

My current RX chain is:

USRP Source

↓

Schmidl & Cox OFDM Synchronization

↓

Frequency Mod

↓

Multiply

↓

Header/Payload Demux

I'm using:

- Sample rate: 50 kS/s

- FFT length: 64

- Cyclic prefix: 16

- Occupied carriers: (-26 ... -1, 1 ... 26)

- Header modulation: BPSK

- Payload modulation: QPSK

- Header length: 1 OFDM symbol

- Length tag: packet_len

The Schmidl & Cox synchronization appears to be working. I can see a clear detect = 1 pulse, and I can also see the received complex signal after the frequency correction/multiply stage.

My problem starts at the Header/Payload Demux.

The Demux is configured as:

Header Length: 1 symbol

Items per symbol: 64

Guard Interval: 16

Length tag key: packet_len

Output Format: Symbols

Sampling Rate: 50 kS/s

The out_hdr output is a dark-blue/vector connection and appears to contain 64 complex values.

I want to inspect those 64 complex values for debugging before continuing with the FFT/equalizer/header decoder.

I tried:

out_hdr

↓

Vector to Stream

↓

Complex to Mag

I configured Vector to Stream as:

Num Items: 1

Vector Length: 64

However, GNU Radio Companion shows a red connection between Vector to Stream and Complex to Mag, so the blocks are not compatible.

I also tried connecting out_hdr directly to a QT GUI Time Sink, but that also gives a type mismatch.

I have attached screenshots showing the flowgraph and the connection/type mismatch.

What is the correct way to debug or visualize the Header/Payload Demux out_hdr output when it is a 64-element complex vector?

Ideally, I would like to inspect the 64 complex values as I/Q or as a constellation before sending them into the FFT.

Am I misunderstanding what "Output Format: Symbols" means in the Header/Payload Demux?

Any help would be appreciated. Thanks!

Antenna moved to a better spot, and both METEORs came in the same night. This is the M2-4 pass from Sep 1, 16:00 UTC, 28.9 degrees maximum elevation.

Three passes, same receiver, same script, same gain:

Sep 1, 16:00, M2-4, 28.9 deg: 1752 CADU frames, peak SNR 11.4 dB

Sep 1, 22:00, M2-3, 42.2 deg: 1279 frames, 8.8 dB

Sep 2, 05:53, M2-4, 16.0 deg: 869 frames, 3.9 dB

The new antenna position measures 10.5 dB better than the old one on a continuous FM reference, 48.8 against 38.3 dB. Two weeks ago the same M2-4 hardware gave me a 6.4 dB rise at the pass peak and nothing decodable. That is what the difference looks like at the far end of the chain.

Two things from this that might save someone else a pass.

Record wide, decide later. I capture 2.048 MS/s centred on 137.5, so both 137.100 and 137.900 are inside the file. That saved the 22:00 pass: I decoded it at the wrong offset first, got zero frames, and only found the signal because the other band was still in the recording. If I had tuned narrow I would have had nothing to go back to. Both satellites transmit on 137.9, which is worth writing on the wall somewhere if your notes say otherwise, as mine did.

A low SNR number is not a reason to bin the file. The 05:53 pass peaked at 3.9 dB and still produced 869 frames and twelve images. I had been treating anything under about 9 dB as hopeless. It is not, at least not with the LRPT decoder in SatDump.

Still unexplained on my side: four captures from Aug 31 and Sep 1 gave zero frames at both offsets with peaks between 0.5 and 4.9 dB. Since 3.9 dB worked above, the number alone does not account for them. If anyone recognises that pattern I would like to hear it.

RTL-SDR v3, V-dipole, SatDump. Good hunting to everyone else chasing these.

Hi all
got this
IR Remote Digital satellite USB TV Stick DAB FM DVB-T RTL2832 FC0012 SDR RTL-SDR Dongle Stick Digital TV Tuner Receiver

recently , i was able to listen to FM radio .

any chance to use it to watch analog TV ? free to air

many thanks

I ordered smth from SDRstore.eu i am on the eu and heard some great and some very bad things on this store?Can yall share yalls experiences?

I just received this image from JMH4 and I noticed that the middle of the H is gone , is it my SDR's fault or the transmitter?

18:58:06 UTC on August 30, 2026
59.4 degree pass

using RTL SDR v4 blog and V dipole

I have an RTL-SDR Blog V4 connected to a mini PC outside on my balcony, which I access remotely.

I now have two antennae, one is a dipole for mainly VHF/UHF and another is a 25 m long wire for MW/SW/HF. I don't want to keep going outside and physically connecting/disconnecting the antennas every time I change bands. Winter is coming in two months and that will be even more challenging! 😂

I wonder what could be the simplest way to keep both permanently connected and switch between them?

Anyone running a similar setup? What would you recommend? Thank you!

I got bored and came up with this because I had an old v3 sitting in a drawer.

https://github.com/KentuckyFriedBlyat/ciphervault

Hey! Does anyone have any feedback regarding the OpenSourceSDR lab I am working on analysing multiple signals from all the RF spectrum and using ML to help me detect signals for alerts, but wonder if there are support? Anyone has any experience on it? I am using a Macbook M1. I was thinking in a pluto sdr+ but found this one cheaper. Thanks in advance for any feedback.