Рубрика «Англоязычные»

Comment on Polls by Also Ben

Nevermind, needed a reload. Can someone come and remove this comment?

Comment on Polls by Ben

“Failed to verify Referrer” on poll completion
Is the website broken, or is there something wrong on my side?

User Projects • Weather Station Spying RTL 433

Weather Station Spying:


Video language is German but pictures also say a lot :D


Statistics: Posted by manuel38 — Wed Jul 08, 2020 7:45 pm

What am I doing wrong? (Help)


First of all I'm from Germany so sorry for my bad English '

I'm kinda new to SDR. I have recently bought a NooElec NESDR Smart and I'm having so many problems with it... I have the problem it doesn't receive anything or just weak signals. I have 3 normal radios here... Two Tecsun and a Sony.. every normal radio gets a lot of FM stations - even DAB+. SDR just the local FM one in my town. I have tested the delivered telescope antenna which was in the package as well as two DVB-T/UHF/VHF/DAB+ Indoor antennas at the window. Just the local FM radio station. One antenna had also a 36dB built in amplifier but that didn't changed anything... I thought it might improve it.

Also every tested program (SDR#, HDSDR, CubicSDR and SDR-Radio) was acting weird with crashing, no received signals, mirroring frequencies to other frequencies...and the worst part... I have to restart every single program when I was changing the frequency... Every time. PC had the drivers and runs Windows 10 64-bit if it matters.

What am I doing wrong? :(

submitted by /u/0xBlackFoxByte
[link] [comments]

Comment on Solving APRS Interference Issues with a Bandpass Filter and Coax Notches by Jose

It is an effective filter, very economical and practical, it can be made with any coaxial cable, rg58, 59, 6, 174, 213, etc.
It is cut at 1/2 electrical wavelength at the frequency you want to attenuate.
Example: to attenuate 97 MHz
1.- 300/97 = 3.09 Meters (1 wave)
2.- 3.09 / 2 = 1.54 (1/2 wave)
3.- 1.54X0.66 = 1.02 meters (multiply by the speed factor of the coaxial cable, in this case 0.66. See manufacturer’s data, since it may be of another value, 0.82, 0.85, etc.)
4.- Connect one end of the coaxial in “T” as shown in the image.
5.- The other end must be short-circuited, that is, join the mesh with the central conductor.
6.- Ready, enjoy a simple attenuator! (a 1 meter long coaxial cable with one end shorted)

Comment on OpenEar: An Easy to Use Windows TETRA Voice Decoder by Jan

Tetra decryption possible?

Troubleshooting Help • Re: Troubles with enabling noise source kerberosSDR

After reinstalling a previous version of the available images (version 1.5) everything seems to work fine.

So I think it is a bug in the newest release.

Statistics: Posted by mcs — Wed Jul 08, 2020 3:52 pm

Troubleshooting Help • Re: EUROSTICK DX 25-2000MHz — Small amount of FM channels ONLY

These rtl-sdr dongles seem to be unreliable trash. Mine worked fine for 3 weeks then it started acting up. My friend ordered one it lasted 4 weeks. Ive wasted countless hours trying to problem solve this turd then I bought a NooElec v4 and it works perfectly in all my favorite sdr applications. My rtl v3 will only stay near the default 105.5mhz in sdr# if i try to change frequency it crashes and becomes unrecognized and has to be physically unplugged / plugged back in to be recognized.

The NooElec has a 2 year warranty and 0.5ppm the sdrblog v3 has no warranty and 1ppm

Statistics: Posted by Scanaholic — Wed Jul 08, 2020 2:31 pm

Imaging the Milky Way in Neutral Hydrogen with an RTL-SDR Part 2

Last month we shared information about Job Geheniau's success with using an RTL-SDR dongle to image our galaxy in neutral Hydrogen. Our galaxy is full of neutral Hydrogen, and lots of neutral Hydrogen together results in a detectable radio peak at 1.42 GHz. This peak is called the Hydrogen line. By scanning the galaxy at the Hydrogen line frequency with a 1.5 meter dish on a motorized mount, an RTL-SDR, and a few filters and LNAs, Job is able to create a radio image of our galaxy.

In Job's previous attempt he created an image by pointing the dish antenna at 168 predefined grids calculated to cover the Milky Way, resulting in 168 points of exposure data. In his latest work Job has created an even higher resolution image by taking 903 points of exposure data. Each exposure took 150s and the total 903 exposures took 8 nights to record. Once all data was collected he uses the same process as before, which is to input all the Hydrogen line data into a standard 2D excel sheet, then use conditional formatting to create a heatmap which reveals the image. He then applies a blur and stretches the image into the Mollweide Cartographic which can represent the entire Universe in one image.

Job has shared with us his PDF where he documented his process and shares his images (note 16 MB PDF file). We also share his full resolution images below, just click to open. We think that these images are quite amazing and an excellent achievement for a backyard radio astronomer.

If you're interested in Hydrogen line radio astronomy we have a tutorial that will help you observe the Hydrogen line peak on a budget. The tutorial could be improved upon by motorizing the dish, allowing you to create images like the ones above. You might also be interested in a similar project by Marcus Leech who took 5 months of hydrogen line observations with an RTL-SDR in order to create an even higher resolution image.

Troubleshooting Help • Troubles with enabling noise source kerberosSDR

I set up everything according to https://www.rtl-sdr.com/ksdr/ and I want to sync the antennas.

When I connect to my PI 4 and visit and go to 'sync', when I check the 'Noise Source ON/OFF' box and hit 'Update' it unchecks the Noise Source ON/OFF box and does not sync the antennas. The enable sync display box remains checked after hitting the update button.

Has anyone seen this before?


Statistics: Posted by mcs — Wed Jul 08, 2020 11:47 am

Июль 2020
Пн Вт Ср Чт Пт Сб Вс
« Июн