Reddit reviews RTL-SDR Blog R820T2 RTL2832U 1PPM TCXO SMA Software Defined Radio (Dongle Only)

Sure!

Antenna: https://www.ebay.com/itm/Altelix-2-4-GHz-WiFi-24dB-Grid-Antenna-Long-Range-High-Gain-Outdoor-Directional/152930295331

Note: For this antenna, you will need to add about 3.5 cm of spacing on the reflector (Like https://i.imgur.com/ruqJmZ1.jpg) I made a 3D printable model just for this antenna that’s just the right size that you can download here: https://www.thingiverse.com/thing:3540047

LNA (Powered by SDR Bias Tee): https://www.amazon.com/Nooelec-SAWbird-GOES-Barebones-Applications/dp/B07GBFNV1H

SDR: https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2 (Note: If this thing gets too hot it will lose signal!)

​

This is plugged into a Raspberry Pi 3+ running goestools (https://github.com/pietern/goestools)

My flagship project I've done with a Pi is having it download satellite images of the earth from satellites overhead.

For instance, this picture was taken from a US weather satellite yesterday using a program called wxtoimg, a $20 USB radio receiver, and a tape measure.

Finally got around to moving the antenna from a second story window to the attic. Went from 150-250 msgs/sec to 800-900. Need to rethink my range rings and labels...

FlightAware Antenna, RTL-SDR V3, RTL-SDR1090Mhz LNA/Filter, Short (6") coax and 15 ft USB cable, RaspPi feeding FA, FR24, ADSBExchange, and a VirtualRadar server

This is better suited for /r/rtlsdr, but the R820T2 has better sensitivity/noise characteristics compared to the R820T. Get one in a metal enclosure and with a TCXO for additional stability and noise protection.

I would suggest a SDR, in all honesty. No risk of accidentally transmitting anything and causing interference. Something like a RTLSDR https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2 it's cheap enough, and you can rig up an antenna pretty quickly.

Get the V3 blog dongle. Has a txco so signals will not drift, bias-t to power lna's or whatever, better build quality and does direct sampling HF with just software. Nice antenna kit (https://www.rtl-sdr.com/using-our-new-dipole-antenna-kit/ ) with this one - https://www.amazon.com/dp/B011HVUEME/ or just the dongle - https://www.amazon.com/dp/B0129EBDS2 . Spec sheet on it - https://www.rtl-sdr.com/wp-content/uploads/2017/06/RTL-SDR-Blog-V3-Datasheet.pdf

This is from an RTL-SDR.com V3 dongle. And it looks "crisp" because a) METEOR-M2 is a digital signal so you don't see the analog noise you might find in a NOAA satellite image, and b) I've sharpened it in GIMP.

In fact I had to clone out some of the data dropouts (some of them occurring on the satellite side) and clean it up a bit. If you're interested, the original unaltered raw image is here. The two thicker bands at the lower and upper third of the image are the METEOR signal resetting itself, so I cloned/healed all that out.

It isn't that. My parents had problems when there was an LED bulb in the floodlight that was mounted about a foot away from my garage door opener. If the flood light was on, the garage door operation was very intermittent.

Grab one of these (https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2) and an antenna and watch happens to the RF spectrum when you get too close to a cheap LED bulb.

Thanks! And also thank you for clarifying the black bars. It's unfortunate that it is a glitch in Meteor but I'm glad to hear its not a local error within my setup.

As for the radio I'm running I'm using a standard RTL-SDR dongle I got on amazon.

You could buy an SDR dongle that will let you use your computer as a radio for about $20. Here's one that goes up to 1700 MHz (I have little experience with these so I can't recommend a particular one). So that will let you listen to 1420 MHz, but you're not going to hear any aliens. Astronomers use huge radio telescopes and computers to try to detect very weak signals across interstellar distances.

While it's not going to be sensitive enough to do any real SETI, you'd still have a radio receiver that lets you listen to an extremely wide frequency range.

https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2/

This one. Also supports bias-t so you can power an LNA if you want.

I have a pair of NESDR smarts, they work well too. I believe then have finer tuning as well.

There is a setting in gpredict I think to that will update when a satellite has AOS, so you might want to just disable that so you can select a single satellite and not have it switch on you automatically.

In that video K7AGE does switch the polarization, most tripod heads will flip from horizontal to vertical - https://youtu.be/1HfvmU_utI8?t=165


Edit: You might want to try picking up some of the NOAA APT weather satellite birds, NOAA-15, NOAA-18, and NOAA-19. They have really strong transmitters, but you'll get a feel of the polar orbits and timing of chasing LEO birds. There is also 3 of them, and you can get multiple passes in each day with them. Just make sure to not transmit at all on the freq (lock out your radio, or use a SDR like a $20 RTL-SDR )

I was with the /r/askreddit crowd.

I ended up getting this one. Same thing but without the antenna. It seemed like better option anyway, everything I read said that you should be building your own antenna or buying a better one anyway. It seems like fun to experiment with different antenna designs too.

https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2

The "blog dongle" is going to be the best bang for your buck kind of thing. It's well built and stable.

For the ham that also loves messing with computers:
RTL SDR dongle for $20

For $20, the RTL-SDR Blog v3 stick is very good and has some features that matter in practice. Bias tee for LNAs if you end up needing to use one (needing a long antenna wire going outdoors is a common reason), aluminum enclosure, a good TCXO, and some ESD protection.

Aside from the actual SDR, the antenna will make a huge difference and you can do reasonably well without spending a lot of money for something fragile and non-portable.

You can get a kit that includes the RTLSDR v3 and a cheap looking but useful "rabbit ears" antenna (see important note below!). It's obviously not a great antenna, but I've used it for receiving NOAA weather satellite images, since you can arrange it as a V-dipole. It's also really lightweight and portable, and if you accidentally break or lose it, or if you leave it outside and it rusts, they sell them separately for a few bucks.

For a slightly more durable and capable, but still really cheap and portable antenna, take a look at the N9TAX Slim Jim. I've had one of those for years and love it, because it can be easily hung up outdoors and taken back down quickly. He makes a few variations, but the one in the link comes with a 10ft cable and SMA connector on the end, and has a built-in velcro wrap for coiling it up and storing/transporting it. It's designed for the 2m and 70cm ham bands, but for receiving with an SDR I've used that antenna on everything from commercial FM all the way up to 1090Mhz ADS-B.

(If you do get that rabbit ears antenna kit, make sure you open the little plastic housing on it and look for wires that might cause a short circuit between the 2 antenna elements. There should be a little resistor connecting them for ESD protection, but there should not be bare strands of wire shorting them directly.

That happened on mine every time the wire moved, and it severely harmed reception until I fixed it by snipping the stray wire strands off. It may also cause damage to the SDR if the bias tee gets activated while the antenna is directly connected and shorted like that, which is more likely than it sounds because the normal TV drivers for the SDR chipset in linux apparently turn on the bias tee by accident, not knowing that there's a bias tee circuit in there).

I'm not that much further along than you, so perhaps others will chime in and in that case I'll defer to their recommendations.

I'd start by buying a receive-only SDR "dongle" which will let you start playing with some of the software. They are repurposed DVB-T (European digital tv) tuners, and the better ones have some additional heatsinks and stuff to make them more frequency-stable.

I have this one, and have given a few similar ones to friends: https://smile.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2/

The major limitation is actually the bottom end of its frequency range... if you want to use it to listen to HF, you need an upconverter. But you can add that later... there's a lot of stuff to listen to just in the FM broadcast band and up through VHF/UHF.

The software I'd start with is "Gqrx" and it's available for multiple platforms, just don't run it on an old beater PC because it's reasonably processor intensive. (Personally I would get a dedicated machine and run Linux on it, because once you get near the actual cutting edge of SDR development, where you'll be pulling random code from Github, that's where the interesting stuff is. Windows means you're going to be stuck waiting for someone to make you binaries or dealing with a toolchain that's different than most of the devs, so they're going to be less likely to be able to help you when you have an issue. Mac OS is seemingly okay but there are some things that are a pain to build.)

Anyway, Gqrx will let you poke around and see/hear what's going on in the spectrum around you. You'll be able to see all the FM and TV broadcast, pagers, cellphones, garage door openers, utility monitors, wireless thermostats, etc. Gqrx doesn't demodulate that many things natively, but you can see and hear them (put it into CW or SSB mode to listen, the digital modes sound very distinctive).

From there... there seem to be a couple of routes. One is to play around more on the software side. The heavy hitter for SDR software is GNURadio, almost all the other software is based on it in some way. It's got a fair learning curve to it, though—this is where I am presently. But it allows you to write modules to demodulate various signals, and if you are a programmer you could start contributing to the cutting edge by working on new modules (they're mostly written in C with glue code in Python, from what I can tell).

To start transmitting you'll need more hardware, because the cheap RTL-SDR dongles don't transmit (well, there are some hacks to make them transmit, but they're real hacks). I haven't settled on what device to get, and it feels like buying a PC in 1996—every few months there's something better/faster/cheaper. If I were going to buy one today I'd probably get a "HackRF One" (about $300) but mostly because I know a couple of guys in my local club who have them, and they seem to be pretty popular—but there are definitely cheaper options around, I'm just not sure how well-supported they are.

Beyond that... it really depends what you want to do. There's some really neat stuff going on right now where cybersecurity overlaps with radio stuff... GPS spoofing and anti-spoofing, for instance, is a big area of research (like you could probably put in 6 months of hard effort and be on the cutting edge of this stuff, I think, at least outside of the military labs). But within traditional amateur radio there's some really neat new digital modes that do slow data rate / low power comms, basically letting you send data over distances at crazy low power levels just barely above the noise floor. I think that stuff is cool—and it doesn't duplicate stuff that your cellphone does. Sky's the limit really.

Just the standard RTL-SDR https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2/ref=sr_1_4?keywords=rtl-sdr&qid=1550504881&s=gateway&sr=8-4

This: https://www.amazon.com/SODIAL-Balun-One-Nine-Low-Cost/dp/B07KW2FYTL/ref=sr_1_13?keywords=rtl-sdr+9%3A1&qid=1550504898&s=gateway&sr=8-13

and a long wire. Just had to use direct sampling.

As promised, here are my sourcing links:

​

• Antenna
  
• Coax
  
• Enclosure
  
• Filter
  
• LNA
  
• SDR
  
• PoE Splitter
  
• Mounting Clamps
  
• Cat6 Outdoor Cable
  
  ​
  
  The rest of it is pretty standard stuff, Raspberry pi, misc hardware from any local hardware store etc...

I found the frequencies by scanning on the radio. It cycles through all the frequencies and stops whenever it finds something. You can set the steps that it scans by. Use CHIRP to set it up more easily, but I did it through the radio menu the first time.

RTL-SDR is a little receiver that you connect to your computer. It basically receives everything at the same time and gives you a visual representation of everything that comes in. You can record with it and decode some stuff that your baofeng cannot.

https://www.amazon.com/gp/aw/d/B0129EBDS2

This a good idea, if you have something creating a lot of nose. This should help you identify it.
This will also let you know if your radio is dead and is need of repair.
Here is a link to a srd dongle

RTL-SDR Blog R820T2 RTL2832U 1PPM TCXO SMA Software Defined Radio (Dongle Only) https://www.amazon.com/dp/B0129EBDS2/ref=cm_sw_r_cp_api_i_2AxUDb29Y3JDC

Ham radio associations like the ARRL probably have the best repository for beginners. A lot of the ham exam study guides and videos have good information for those wanting to learn about RF. I picked up some amateur radio books from the 60s at a local library book sale and they proved to be quite valuable guides.

Also, and I can't recommend this enough, pick up an RTL-SDR. For less than $30 and the cost of a diy antenna you can listen to literally anything from the LF to UHF range. Satellites? Old fucks on 2m? Air traffic? Garage door openers? ADS-B? You name it, SDR can do it.

OS is Raspian; Documentation can be found all over the place for installing.

Software used for tracking trunks in the Baltimore Co MD, Carroll Co MD, York PA area is called OP25

Method of configuration that I used can be found here (Big shout out to Johns tech blog) This guide is amazing.

https://www.hagensieker.com/wordpress/2018/07/17/op25-for-dummies/

8 Inch monitor can be found here https://www.amazon.com/gp/product/B07FP2F9XY/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1

The antenna used can be found here in which I retrofitted with a camera tripod

https://www.amazon.com/gp/product/B075QCJM6S/ref=ppx_yo_dt_b_asin_title_o03_s01?ie=UTF8&psc=1

rtl-sdr dongle used can be found here

https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2/ref=sr_1_2_sspa?crid=3RE7FZK09J0QX&keywords=rtl-sdr.com&qid=1558445253&s=electronics&sprefix=rtl-sdr%2Celectronics%2C124&sr=1-2-spons&psc=1

​

The case that I am using for this Raspberry Pi B+ can be found here

https://www.amazon.com/gp/product/B07G1LMFRG/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

The speaker that I wound up using and not in this pic is an Anker Soundcore boost, but I also use headphones when I take this to the office.

All radio system-specific information can be found at radioreference.com.

Getting the true control channel can be challenging sometimes as the db on radio reference is not always correct, at least for my area. Also, trial an error I was able to determine that the offset for my dongles is -1.

Try this one
I have this SDR for my pi. It's only $20. You may also consider decoding ADS-B transmissions from aircrafts to have your pi show a radar-esque display.

Yup, you got it. There is also an option to just by the dongle if you don't need the antennas too.

edit: https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2/

Correct. You don't even need to know which frequency they're tuned in on specifically, you could look at the whole spectrum using a Software Defined Radio like an rtl-sdr or bladerf with an upconverter and then spot them in a waterfall like SDRTrunk, SDRTouch, HD-SDR, SDRSharp, etc etc.

Wait, so this one is enough for L Band HRPT and HRIT?

And for Op, if you live in the right place where you can recieve goes, you could look into it, but it is a big step up in complexity from APT.

800mhz is usually trunked digital radio encoded using P25. Looking at the radio reference page for your county confirms that:

Roanoke City / Roanoke County (Project 25)

Virginia Statewide Agencies Radio System (STARS)



If you have time to tinker you can pull in and decode P25 with an RTL dongle, this will save you a couple hundred dollars. Depending on your technical ability this route will take anywhere from 6-40 hours of work to get to the point where you're listening to those frequencies.

OP25 is a great piece of software and the error correction code it has is amazing. You could probably pull in an intelligible signal using a coat hanger for an antenna. The only downside is that it can be rather difficult to get setup and decoding.


There's another project that I've used which is a lot easier to get running but more difficult to configure is SdrTrunk. This project will run in Windows, so you won't need to try to get it running in a VM or install linux on a machine to get it running; But I find the interface to be confusing and lacking features that OP25 has, like Skip and Lockout for channels that are overly chatty (automated fire calls, ambulance dispatch, etc.)

Hopefully this is enough to get you started, If you need clarity or more information just post.

This is what I use, the NooElec Ham it Up upconverter. Image from before assembled. Works great, I listen to HF every night.
http://imgur.com/a/WIIap

Apparently, though, this might be another option, apparently does HF without an up converter (though I'm dubious for some reason):

https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2/ref=sr_1_27?ie=UTF8&qid=1484715796&sr=8-27-spons&keywords=nooelec&psc=1

This is the dongel I bought.
https://www.amazon.com/gp/product/B0129EBDS2/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

I need to go form this to coax but I am not sure what this connector is called.

https://www.amazon.com/gp/product/B0129EBDS2/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Sorry! I probably should have included that

I admit, the 6Ghz isn't doable for $50, but a pair of RLT-SDR USB dongles would get you 4.8MHz of bandwidth from 500kHz to 1.7GHz for $42. If my headliner was drooping and that's what I found it is what I'd do in a heart beat!

For $289 you can get the LimeSDR that gets you 61MHz of bandwidth from 1MHz to 3.8GHz

For $300 you can get the HackRF One that gets you 20MHz of bandwidth from 1MHz to 6GHz

> they are enclosed in metal shells instead of plastic and are available on amazon

Yep. The dongle I'm using for FlightAware is this one. Connected to SDR# with the filter I've got very little noise at ADS-B frequencies.

> a 1090 inline bandpass filter on their antennas to reduce noise...

The FlightAware filter is a big beast, compared to some of the other ones I've seen (like Adam's 1090 filter), it's also fairly heavy, about the weight of 2-3 AA batteries. There's been a couple of guys using satellite diplexers as filters as well, they're the size and weight of a cable tv splitter and are effective because the diplex circuitry doesn't pass anything under ~900 mhz.

They're a pretty decent SDR, but its current hardware config is not setup to receive frequencies below 25 MHz. There are experimental drivers that will let you expand your listening range lower but normally not quite into the AM BC band. I've had pretty good luck with those drivers, much better performance than others report - may have to do with the antenna and gain setup I connect them to.

However for that particular SDR if you want to listen to AM broadcast and LF/VLF etc you will need to perform the direct sampling modification. There are many tutorials with pictures online to step you through that mod.

If you want one that will work out of the box with your desired frequency range in the same price bracket there is the RTL-SDR Blog V3 Dongle. Works great, I had one. Gave it a friend to get him interested in SDR. Wish I had it back LOL.

Make sure any listing you buy this one from indicates "V3" as that has the hardware mod nicely done at the factory.

Here's an amazon link: https://www.amazon.com/dp/B0129EBDS2/

RTL SDR is helpful to figure out which codes are sent from the original fob and the new fob.

Also read the information sheet on the clone fob sellers page:

> It can't copy two-way remote control and rolling code remote control (Rolling code chips start with HCS commonly, such as HCS200, HCS201, HCS300, HCS301, etc.)
NOTICE: We strongly suggest you to check the IC CODE of your original remote key. The replacement remote key may not work properly if you copy the code from an unsupported IC.

With your current radio, I don't see a practical way.

This can get vhf/uhf and technically HF (430 khz) but with sub par performance. With a upconverter, you can get 430khz nicely, two good ones are the spyverter and Ham it up.

Keep in mind you'll need to make or buy antennas to do either of these things.

Ok.. Good to know. I've found this on Amazon, but it appears it doesn't come with an Antenna, and I can't seem to find a kit that contains one at the moment. What would you recommend as a good starter antenna that can pick up a decent range?

It seems like the dongle + antenna is sold out, but I have a 15.5" dual-band antenna, that is marked 144/430 Mhz, that I picked up from a garage sale a while back. Will this work with the dongle here?

Or a DVB Tuner / RTL-SDR used to watch broadcast TV in Europe or view/record wireless signals everywhere else.

(Remote comes with one like this - but don't buy that one. Buy one like this or this for better shielding - and the first one won't cover up three USB ports on a /r/raspberrypi.)

See /r/rtlsdr

This one is just the dongle, but you can buy the kit for $30 which includes a cheap whip. If you have a TV antenna, that works too though.


As far as books for gnuradio, I'd just do some of their examples and refer back to your Linear System & Signals course or communication theory book

Hope that helps!

Well looks like it should work, you may need to route through digital audio though software like dsdplus to decode digital audio. I'm not seeing anything about it being encrypted.
https://www.radioreference.com/apps/db/?sid=195

If you don't have one yet I recommend this rtl-sdr. There is also a version that comes with an okay antenna for about $5 more.
https://www.amazon.com/dp/B0129EBDS2/

You will want two of them, one that only listens to the trunking control channel and the other to do the voice frequency.

I am using an RTL-SDR Blog R820T2 RTL2832U that requires no upconversion (https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2/ref=sr_1_2?ie=UTF8&qid=1497199171&sr=8-2&keywords=rtl-sdr+blog). So, yes, version V3 with q-branch sampling. The AM high-pass filter is also an RTL-SDR Blog product (https://www.amazon.com/Broadcast-Reject-Filter-RTL-SDR-Blog/dp/B01N9SHS7P/ref=sr_1_1?s=electronics&ie=UTF8&qid=1497199381&sr=1-1&keywords=rtl-sdr+blog+am). The reject filter has a cutoff of 2.6 MHz, so anything below that is severely attenuated. The 9:1 balun was an ebay purchase (http://www.ebay.com/itm/9-1-BALUN-TRANSFORMER-FOR-LONGWIRE-SHORTWAVE-ANTENNA-COMMON-MODE-NOISE-REDUCED-/182614185483?hash=item2a84a7560b:g:JK0AAMXQs6FRTyHa). Sorry for all the links, but they'll do a better job of describing everything. :)

Like this one?

RTL-SDR Blog R820T2 RTL2832U 1PPM TCXO SMA Software Defined Radio (Dongle Only) https://www.amazon.com/dp/B0129EBDS2/ref=cm_sw_r_cp_apa_i_dJcDDb1WRSA5V

Edited to include the right link

What brand/model/chipset did you choose? This dongle seems well received and I have plenty of spare antennas, RG/LMR coax and RF connectors crimp my setup. Now know I could check wikidevi.com for Linux compatible devices with stable firmware but I'd love to hear what you've used.

I'm not familiar with that one. I got this one, but you'll need SMA antenna so you might want to get the kit version. You'll be able to listen to a lot more than just FM commercial radio with it though, maybe it's overkill.

This for my SDR and this for my antenna.

Hey good point. Here's a link to the model. It's a female SMA connector.