>have shortwave radio
>hear of SDR
>buy standard DVB-T Dongle with suitable chipset
>wanting to receive EVERYTHING
>first week listen to FM radio stations, record multiple with gqrx
>second week listen to 446 MHz PMR transmissions
>third week listen to APRS -- record text
until now everything was fine
>fourth week
>want to listen to NOAA weather sattelites
>read articles about weather fax, apt ...
>install hamfax (fax software) (works)
>install gpredict (sattellite tracing software) (works)
>read article about s.o. who received NOAA-15 signals with rtl_sdr device ( http://www.dk3wn.info/sat/wetter/sat_noaa18.shtml )
>wait for NOAA-15
>wait for signal in gqrx
>nothing
>check antenna -- is ok
>check cable -- is ok
>chekc other (local) signals -- can receive them
WHAT THE FUCK!
WHY CAN'T I RECEIVE THE SATTELITE
Why can this other guy do it?
>tfw i can't into receiving weather sattelites
(pic related isn't tuned to the right frequency, but the freq. at which NOAA-15 transmits (137.5 MHz) should be visible!!!)
>>55139628
>buy standard issue dvb-t dong
>not expecting every standardized chipset to be backdoored and refuse to listen to any sensitive signals
lel
you have some reading up to do.
>>55139657
hack rf one?
>>55139657
>sensitive signals
>weather sattelites
...
also:
>other person using rtl_sdr hardware
>showing pictures!
what is wrong?
>>55139657
>some reading
what do you suggest
>>55139628
Do you have a right hand circularly polarized antenna tuned to 137 MHz?
WXtoImg for decoding the APT signal?
>>55139745
one of these?
>>55139792
You capturing at the right time? Ever try Orbitron?
>>55139628
What antenna are you using? i made this with some coax wires, pcb drainage tubes and tape. The noaa signal is very weak, try getting to higher ground
>>55139657
i got this with a chinese 5 dollar dongle and my shitty homemade duadrifilar helix antenna when i tried it a year or two ago
>>55140487
>rained today
Thanks, but one year too late.
>>55139628
stop being autistic and just get your weather form the internet you stupid nerd fuck
can you listen other devices with it?
like car remote key or IR gate?
im a newfag to this shit, what the fuck is all of this? and what is it used for?
>>55141251
Yes, i can receive almost all of my neighbours' outdoor temperature and humidity sensors with a program called "rtl_433".
I'm going to buy/build myself some different antennas (for different bands).
That should do it.
>Hardware AGC on
>LNA gain at max
Nice overdrive. Try HW AGC off and LNA gain around 10dB.
Also with high probability your antenna is not usable with that wide scale of frequencies. If you have space available I'd recommend some discone antenna for SDR stuff. Something like Diamond D3000N.
>>55143332
https://www.amazon.de/gp/aw/d/B004A816MY/ref=mp_s_a_1_1?qid=1466278556&sr=8-1&pi=SL75_QL70&keywords=Diamond+D3000N
>127€
Buying a 15€ (cheap) radio receiver and then adding an expensive antenna ..... Meh.
>>55143332
>>55143991
Make your own antenna m8, i used this guide
http://www.g4ilo.com/qfh.html
>>55146234
Thank you for providing that link!
>>55139628
How did you listen to aprs? What country you in? What frequency? What's your antenna like? I'm new and trying to find all this cool stuff on my device
>>55143332
https://www.amazon.de/Albrecht-SCANNERANTENNE-SKY-SCAN-MAG-1300/dp/B005CN6MC0/
????
I'm snooping on police/ ambulance pacer transmissions. I'm going to start listening on satellites soon, i think.
Satellite signals are vastly weaker than most anything terrestrial aka on the ground that you're going to receive. Shit, your cell phone is radiating more powerful signals at any given moment than the strength of the signal from a satellite is by the time it gets through the atmosphere and to your antenna whatever or wherever that might be.
If you do some research you'll find that people either buy or construct helical antennas like the one pictured for receiving satellite signals with a bit more *uNF* to them. You can use LNAs (low noise amplifiers) as well with traditional antennas to help but, a helical tuned directional gain antenna is precisely what you need to get the best possible signal reception from anything in orbit.
They're easy to construct from bare electrical wire, not that hard at all, but getting the coil shaped properly is the tough part. There are plenty of guides out there for that however.
Is it going to be expensive to buy stuff to start with with SDR?
>>55146643
>see that image
>the waterfall
>all yellow and red and nothing useful visualized
My god man, back the fuck off the slider on that, you should be looking at something like this for actually useful visual information.
Reduce the middle slider on the right (Contrast) till you see pure black in the background (which would normally be the noise you DON'T want to visualize) so that any actual signals stand out from the noise.
See how that works? With what you have now you're not getting much of anything useful but a fucking wall of "fire" basically. Adjust the contrast and the signals will jump right the fuck out and be easy not only to see but to identify just from what they appear as on the waterfall.
>I swear to god the image CAPTCHA I just got was WATERFALLS
>Google is spying on my god damned keystrokes
>AARRRGGGHHHH
>>55146418
I'm in Europe: Frequency is 144.8 Mhz
>>55146763
Ah, thanks.
Much better.
>>55146763
>fucking wall of "fire"
keked!
and true!
>>55139657
Confirmed for not knowing shit about RF.
>>55146970
It's one of those things that people new to SDR applications tend to misuse the most, they'll have waterfalls that look pretty much like that and you can't realistically pick out much of anything useful from the visual info. Adjusting it so the noise fades into the background (literally) allows the actual signals to appear and stand out which is the entire purpose of the waterfall. After awhile you can tell exactly what type of transmission format it is just by the signal's visual representation.
Here's a site that offers a shitload of visualizations to get people started:
http://www.sigidwiki.com/wiki/Signal_Identification_Guide
And here's two sites to help ID signals just from what they sound like, especially the digital formats if you don't decode them with something like DSD+:
http://www.kb9ukd.com/digital/
http://www.w2sjw.com/radio_sounds.html
