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Intro to SDR and RF Signal Analysis

elttam.com.au

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Re: Intro to SDR and RF Signal Analysis

#21

Post by lowleveldrone »

forg0t_username wrote: post #6

If you want to dabble for _cheap_ with SDR, the RTL-SDR [1] is a It allows to listen to FM radio, decode most 433MHz devices (weather stations), car keys signals, and even NOAA weather satellites [2] with a DIY antenna [3]. [1] https://osmocom.org/projects/sdr/wiki/rtl-sdr [2] http://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weath... [3] http://tinhatranch.com/how-to-build-a-qfh-quadrifilar-helix-...

For what it's worth, you can get very good reception from NOAA satellites using a much simpler antenna: http://www.rtl-sdr.com/simple-noaameteor-weather-satellite-a...

Said from experience of having built something more complicated and having it perform worse than two pieces of copper tubing stuck in a piece of scrap plastic.

Re: Intro to SDR and RF Signal Analysis

#23

Post by pjc50 »

echelon wrote: post #7
forg0t_username wrote: post #6

If you want to dabble for _cheap_ with SDR, the RTL-SDR [1] is a It allows to listen to FM radio, decode most 433MHz devices (weather stations), car keys signals, and even NOAA weather satellites [2] with a DIY antenna [3]. [1] https://osmocom.org/projects/sdr/wiki/rtl-sdr [2] http://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weath... [3] http://tinhatranch.com/how-to-build-a-qfh-quadrifilar-helix-...

Can you suggest something that could be used to read or reprogram wireless access cards, such as the HID Proxcard II? I want to clone my apartment's key fob into a bracelet I can wear when I go jogging.

Clarification for the audience: "RFID" has very little to do with radio or SDR. Communications are done with a coil in the "near field", which also powers the tag.

Re: Intro to SDR and RF Signal Analysis

#24

Post by awqrre »

forg0t_username wrote: post #6

If you want to dabble for _cheap_ with SDR, the RTL-SDR [1] is a It allows to listen to FM radio, decode most 433MHz devices (weather stations), car keys signals, and even NOAA weather satellites [2] with a DIY antenna [3]. [1] https://osmocom.org/projects/sdr/wiki/rtl-sdr [2] http://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weath... [3] http://tinhatranch.com/how-to-build-a-qfh-quadrifilar-helix-...

You can also track your neighbors' energy usage by decoding their smart meter transmissions (around here, they transmit about every minute). https://github.com/bemasher/rtlamr

I can read about 40 smart meters from inside my home using the antenna that comes with it.

Re: Intro to SDR and RF Signal Analysis

#25

Post by ChuckMcM »

wonderous wrote: post #19

Beside HackRF One, I've been looking at LimeSDR. Are there any other comparable options?

Analog Devices has done the ADALM-PLUTO which is less expensive than the HackRF-One. I don't have one of those but I do have the HackRF one, and if UPS is to be believed a LimeSDR :-). The cost/capability matrix is sort of

RTL Dongles -> ADALM -> HackRF-1 -> LimeSDR -> Ettus SRP

The RTL's don't transmit but all of the other ones can.

Re: Intro to SDR and RF Signal Analysis

#26

Post by ChuckMcM »

fellellor wrote: post #13

Are there companies/sectors that look for candidates with these skills, or is this more focused towards hackers and hobbyists?

I am always looking for people with SDR skills :-). Constraint being I need US citizens (naturalized or native) given that the company I'm working for is doing contracts for customers that require that.

Re: Intro to SDR and RF Signal Analysis

#27

Post by wyldfire »

awqrre wrote: post #24
forg0t_username wrote: post #6

If you want to dabble for _cheap_ with SDR, the RTL-SDR [1] is a It allows to listen to FM radio, decode most 433MHz devices (weather stations), car keys signals, and even NOAA weather satellites [2] with a DIY antenna [3]. [1] https://osmocom.org/projects/sdr/wiki/rtl-sdr [2] http://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weath... [3] http://tinhatranch.com/how-to-build-a-qfh-quadrifilar-helix-...

You can also track your neighbors' energy usage by decoding their smart meter transmissions (around here, they transmit about every minute). https://github.com/bemasher/rtlamr I can read about 40 smart meters from inside my home using the antenna that comes with it.

Is there an easy way to confirm which one's yours? Serial number visible from the exterior of the meter e.g.?

Re: Intro to SDR and RF Signal Analysis

#29

Post by signa11 »

fellellor wrote: post #17
femto wrote: post #15

Earlier quoted context omitted.

Virtually every professional radio is software defined to some extent these days, so every company that designs radios wants signal processing and information theory skills, more so if they are doing proprietary protocols rather than implementing a standard. It's pretty well the same skill set, whether you are designing or analysing systems. There is a surprising amount of reverse engineering in building radio system…

Where can I read more about this? It's always nice to see RF and Signal Processing stuff on HN.

> Where can I read more about this?

there is the canonical Fundamentals of Wireless Communication (https://people.eecs.berkeley.edu/~dtse/book.html) which is pretty good. also, iirc, there is a book by oppenheim as well (signals and systems, i think)

edit-00k : yes, oppneheim book is called 'signals and systems' and it is available on ocw as well (https://ocw.mit.edu/resources/res-6-007-signals-and-systems-...)

Re: Intro to SDR and RF Signal Analysis

#30

Post by platz »

lowleveldrone wrote: post #21
forg0t_username wrote: post #6

If you want to dabble for _cheap_ with SDR, the RTL-SDR [1] is a It allows to listen to FM radio, decode most 433MHz devices (weather stations), car keys signals, and even NOAA weather satellites [2] with a DIY antenna [3]. [1] https://osmocom.org/projects/sdr/wiki/rtl-sdr [2] http://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weath... [3] http://tinhatranch.com/how-to-build-a-qfh-quadrifilar-helix-...

For what it's worth, you can get very good reception from NOAA satellites using a much simpler antenna: http://www.rtl-sdr.com/simple-noaameteor-weather-satellite-a... Said from experience of having built something more complicated and having it perform worse than two pieces of copper tubing stuck in a piece of scrap plastic.

I've been dabbling with RF, but I don't quite understanding the appeal of downloading NOAA sat images. It is simply 'hello world' for receiving sat downlinks?
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