Is Sup Forums interested in radios or more specifically the rtl-sdr? Did you get one of the the generic chinese ones or one of the custom higher quality ones? What do you use it for? Personally I use mine to listen to my state police's trunked radio system.
I remember seeing a radio thread here before and I was wondering if anyone here was still interested.
i tried to get into SDR ages ago but these rtl sticks are extremely expensive($600+) because they're banned for being non compliant.
also funded one of the many kekstarter projects for a high end device but again was destroyed at customs.
Where do you live? These sticks are usually $10.
Just try to import one?
Of those pictured the aluminum enclosed one (second from the right) from the RTL-SDR blog is the best one available, cost about $20 for just the stick, $25 for the stick + 2 somewhat useful but not fantastic antennas (but you can always get better ones easier now thanks to the SMA connector and not the MCX one on the older sticks).
Been into RTL-SDR hardware for a few years, it's an interesting way to do things but it's still too complicated for the average person that just wants to listen in. The fact that there is still no one single application that can "do it all" is problematic - to monitor a trunked comms system you either a) have to use OP25 on Linux (for P25 Phase I and II decoding but it does have the best audio quality of any software related tools out there and it can monitor such trunked systems with just one RTL stick) or b) you have to use Windows/macOS/Linux and multiple applications (SDR#, DSD+, and Unitrunker and SDRTrunk and all sorts of other stuff)as well as at least 2 RTL sticks all working in conjunction with one another and it's still just not as easy to use as a handheld scanner would be to get the same tasks done.
Yes it's cheap as hell and the software is free (thankfully) and it does actually work but as stated it's rather complicated to get things working well if at all.
Someday someone with actual skill and talent will code up a single app that can do everything and offer up the GUI that looks like a traditional scanner where someone can just do things much easier and without all the fucking hassles either.
As someone that's been listening to and using "police scanners" since the 1970s (yes I'm older than effectively every one of you, guaranteed) so this is a new way of doing things but, sometimes it just gets boring when you can't actually do something with any level of ease like an actual physical scanner does and it's frustrating as hell because we should be able to do such things.
We need better software.
Unit runner supports native r820t. But the software is due for a complete overhaul as it wasn't designed with SDR in mind.
There's also sdrtrunk with the jmbelib a pure java app that handles dongles trunking and p25 decoding
And both of those are complete pieces of shit, for the most part. Yes they can function to some degrees but again, nobody has created an application on any platform that can and does emulate a physical scanner as well as should be capable at this point in time. Considering how woefully underpowered a handheld scanner is compared to a desktop/laptop computer or even a fucking smartphone these days someone out there should be capable of creating such a software tool but hasn't done it yet.
Hell, if someone would do such a thing and put it up on Kickstarter I'd have cash ready to buy if it can do what most of us want all in one package.
I'm just sick of having to use so many different things to even get a signal I can monitor.
There's still a long long way to go with SDR and computer software, a very long way.
Currently studying up for a license because I want to get a hardware receiver. I had some interest, but then got addicted to hunting for stuff when I spent two days doing it during a wireless CTF at a con.
Just built a pizza pan antenna for my SDRplay and got decent results.
I wish I knew enough to try to code something a little more unified. I've messed around a little with GNUradio and Luaradio. So many things are windows only and it's a pain to pipe the audio around.
I'm interested in design of millimeter-wave radio/radar circuits (10+GHz).
Circuit design for devices operating at such high frequencies is typically quite complex and you can't normally use off the shelf parts. For instance I can't use traditional oscillators such as LC resonators, Schmitt trigger oscillators, phase shift oscillators, crystal oscillators, etc. to generate microwave signals. You end up having to use crazy active devices with weird negative resistance regions like Gunn diodes, MESFETs, HBTs, or HEMTs and good luck even finding places to buy that shit let alone getting a good price. Also impossible to find datasheets and schematics and no places to go ask around if you need help with the finer points of microwave circuit design.
I'm pretty sure you only learn this crap if you go work for a company that specializes in designing millimeter wave products. I don't even think most colleges teach this stuff.
bump for interest.
how the FUCK do I start doing packet over radio on linux so I can browse in my neighborhood using my glorious fiber net?
Can anyone post some starter info or link? I can't even understand that TCXO thing
I just bought the second one from the right along with a couple of the antennas. I'm new to SDRs, and I looked through the InstallGentoo wiki page on them, but is there anywhere that gives a comprehensive guide for beginners on these things? Preferably Linux oriented.
Why is the aluminum one better?
Doesn't OPs pic show them all using the similar chips?
Why the interest in police scanners? With an amateur radio license (which you should obtain) you can do so much more with even a cheap whip antenna. Last
week there was a moon bounce competition, you can listen to satellites, planes, and boats with those things too. Police scanner is by far the most boring thing to do with them.
Checked also look at an amateur radio license for an intro into radio, Gnu radio is a great foss program to set up receive/transmit on them. There are a bajillion amateur radio forums that would be willing to help you. If also check out the hackRF. It's $300 but open source and there's lots of documentation.
I think it's due to the devices becoming very hot.
Cool, I'll look around to see if I can get a license. If I end up doing more with these I might purchase a hackRF later on. Will give GNURadio a shot, too. Thanks.
Will I need a separate device if I want to transmit something, as well?
TCXO = Temperature Compensated/Controlled Crystal Oscillator
Crystals used in most situations can be affected by temperature especially the circuit they're a part of throwing off the frequency they're used to tune with. Having one that's temperature compensated or controlled means it'll stay "on frequency" even when the circuit gets hot/warms up.
It helps in three respects:
1) It dissipates heat away from the circuit allowing it to cool better
2) It provides a level of EMI/RF shielding on the internal circuitry
3) It provides a better more secure/sturdy form factor instead of the plain old plastic shit from the previous generations of RTL devices (especially the antenna connector)
HackRF offers transmit capability, just incredibly low power capacity (like 50 mW or something similar). Could always feed that signal to some other transmitter amplifier I suppose.
But HackRF is $300+ typically (might find a used or dev device, they used to have a series called HackRF Blue that were prototype models more than anything else) for a bit less money.
Dongles yes, hackrf no.
So what exactly does an amateur radio license do for me if I can't transmit on an RTLSDR?
Nothing. You only need a licence to transmit.
I had someone from the FCC knock on my door because apparently someone saw my antenna and called them. When I told him what I was doing with it, he didn't give a shit. If you're only receiving, in your home, you don't need a license. Now you can't drive around with a receiver because it's illegal to listen in on the cops while you're in your car. This is the only caveat.
is anyone interested in HAM radio with motorola hardware?
yeah, i just bought a RTL-SDR v3 stick from Amazon for about 20 bucks, works great here, and in Q mode it gets down to 100 kilohertz
HDSDR is good, SDR# is not bad either,
>illegal to monitor law enforcement while mobile
Maybe in your bumfuck Kekekistan or someplace of a similar nature but not everywhere, nope.
These are useless now that most government agencies are encrypting their radio transmissions. My local PD encrypt, so I just typically use mine to listen to am/fm radio.