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You are here: Home / Guest Appearance / Impedance Matching episode / #214 – “Impedance Matching” With Charvat And Ossmann – Recurring RF Remontados

#214 – “Impedance Matching” With Charvat And Ossmann – Recurring RF Remontados

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Welcome back Michael Ossmann and Greg Charvat!

PolandRFtower

  • Since we last talked to Greg, he has made many more media appearances.
  • Engineering on TV shows continues to be a lame proposition. The auxiliary Mythbusters crew just got laid off. Joe Grand told us about the rigors of being on an engineering show when he was on The Amp Hour.
  • Mike has started releasing videos in his SDR series. These are a supplement to the in-person 2 day classes he teaches at security conferences.
  • Power and low cost requirements drove choice of no FPGA on the HackRF One (now shipping!).
  • Greg has friends at the MIT Haystack observatory that have had doing similar SDR issues and don’t hire FPGA programmers.
  • Mike is planning to do some add-on boards for the HackRF; limpkin has already made some of these. The higher sample rates means you could see “farther” (up to 1Km) and more detail of things in the distance. This would also allow for range dopler imaging.
  • Greg says that many Signal Processing PhDs talk about spacial frequency domain.
  • Mike says he needs to buy Greg’s book. You should too!
  • Mike has been playing around with CW radar using “arduino radar” modules off eBay.
  • Greg recommends instead using FMCW 24 GHz modules. One good example is RFbeam microwave K-LC1a, which cost roughly $5.
  • The coffee can radar kit is currently avaiable from Quonset for $600. Lincoln Labs make one for their grad students and UC Davis are developing an Arduino shield.
  • The Amp Hour (and Greg) recommend the upcoming kit of Tony Long, former guest of the show.
  • Greg wrote a Circuit Cellar op ed about  the future of small radar tech.
  • RADAR is seeing more use in the home. One example is a video game system shown by MIT Media Lab that can detect gestures.
  • Mike gave a DEFCON talk about the NSA playset. This is the set of tools used for spying, many of which used RF retroreflectors.
  • Greg recommended that Mike skips the cheap Chinese modules and instead get a surplus police radar unit. Another good choice is the hot wheels radar gun which surprisingly runs with a 10GHz chipset. Jeri did a video with the toy:
    [tube]https://www.youtube.com/watch?v=Dhp21FxttWM[/tube]
  • Mike has been trying spread spectrum for his retroreflector setup.
  • There is a research paper about doing arbitrary quadrature modulations in a backscatter device. They discuss a simple passive device that is a MOSFET with an antenna. Awesome.
  • Mike uses antennas from WA5VJB (Kent Britton). These are log periodic, PCB based, antennas that can go from 850 to 6500 MHz.
  • Chris was embarrassed for not doing more with his USB TV tuner. Mike explained that many don’t because they are lacking PAL connectors (which convert to SMA or BNC).
  • Greg talks about how LabView is great for getting set up with quick experiments and validations. Chris used to use this in his FPGA DSP work.
  • The HackRF will hopefully be used for derivative/add-on project.
    • Jared Boone (one of the HackRF team members) is working on the PortaPack.
      [tube]https://www.youtube.com/watch?v=koS-RobcKXI[/tube]
    • There are people that are connecting the HackRF with the BeagleBone Black.
    • Mike is working on Filter/LNA board between HackRF and the antenna for extending filtering capabilities.
    • He also wants to possibly do a VNA board that could also do RADAR.
  • Greg explains that a prior company he interned for made coversion boxes to make the HP8510 into a RADAR array.
  • Mike used to get grant funding (which helped to develop the HackRF/Daisho) from the Cyber Fast Track program (which recently ended).
  • Mike also used to work on the P25 digital radio at the Boulder lab of the Dept of commerce (they also do the atomic clock, wwv  & wwvb).
  • All were a bit skeptical of the goTenna use cases, but were intrigued by the use of the MURS. This band is similar to the similar to FRS.
  • We aren’t completely sure about the goTenna but future filings about their FCC activity will be found on the FCC website.

Many thanks to Mike and Greg for returning to the show! It was great to get them together to hear brainstorming about how the coffee can radar kit and the HackRF might work together some day!

Thanks to the Poland MFA for the picture of the tower.

Comments

  1. rasz_pl says

    September 3, 2014 at 6:56 am

    So it looks like Greg is still working for NSA 🙂

    why trigger? Just Timestamp. This isnt analog, there is no hurry, no need to react to anything immediatelly,you wont lose any bits, its all streamed into computer ram. Timestamp when you transmit, timestamp when you start receiving and let software take care of the rest.

    HOLY EFFIN CRAP, That was one of the best shows ever! Im loving this format of inviting two people from different, but crossing domains, and just letting them talk to each other.

    I highly recomment Mikes SDR course.

    Btw every time I hear or see Mike I cant stop thinking about Jon Lajoie, you are like twins!

    https://www.youtube.com/watch?v=bSR3h1wUoS8

    • Chris Gammell says

      September 3, 2014 at 8:15 am

      Agree, I hope to do this format again, that was great to hearing what they asked one another about (I got to just sit in the middle and ask about stuff that confused me)

  2. Alan “W2AEW” Wolke says

    September 3, 2014 at 10:31 am

    Have you seen my video that analyzes the signal from that Hot Wheels Radar Gun? I use that device as part of my “demonstration kit” for Radar analysis…
    http://www.youtube.com/watch?v=e4UWqrCwCC0

  3. ru4mj12 (@ru4mj12) says

    September 3, 2014 at 2:51 pm

    What happened to Dave?

  4. kfitch42 says

    September 3, 2014 at 2:52 pm

    About the Wolf Blitzer incident: Was the radar guy who went on before Greg actually a sonar expert? Or, did they get two radar experts and just say … it rhymes, close enough.

  5. Chris Gammell says

    September 3, 2014 at 2:56 pm

    On vacation, like we mentioned about 15 minutes into the episode.

  6. Jon Klein says

    September 4, 2014 at 2:52 am

    Great podcast!

    I just purchased a few RFbeam Microwave K-LC2 24 GHz radar modules to play with.

    RFbeam Microwave doesn’t have a US distributor and won’t sell to the US in large quantities because the modules aren’t FCC certified, but they’ll sell sample quantities if you email them directly. It cost me about $180 for five modules shipped.

    • naikrovek says

      November 6, 2014 at 6:12 pm

      Where did you get them? I can’t find resellers.

  7. Nathan Rima says

    September 4, 2014 at 3:05 pm

    Great show and timely for me. I have recently signed up for a uRadar unit designed for use by cyclists – another ‘new’ use of the technology (http://www.dragoninnovation.com/projects/41-backtracker-by-ikubu). Their unit, although not open hardware, uses a radar unit that is in the ISM band and I think in the 24GHz. They are getting EU and FCC certification. They are also releasing an open API for the unit.

  8. Derek says

    September 4, 2014 at 9:42 pm

    Awesome show guys. I too love this format when two people in similar fields get to share experiences and new ideas or solutions are realized. This is by far the best show, slightly better than The Henry Ott one which also blew my mind.
    Keep it up Chris, and let’s get that slacker Australian guy back on the show! What the heck has Dave been up to?

  9. chexclaim says

    September 4, 2014 at 11:05 pm

    Excellent mixture of lecture and brainstorm session. One of the best shows. Thanks! CH!

  10. kiu112 (@kiu112) says

    September 5, 2014 at 6:22 am

    Classic here-is-the-wrong-expert: https://www.youtube.com/watch?v=atfNL0_KAcs

  11. David Bley says

    September 8, 2014 at 12:32 pm

    HP as a brand is dead. Having HP meant you had the very best. Now it means you’ve been hoodwinked into buying poorly performing and supported stuff.

    I think radio is still magic. HackRF is somethng that has interest for me. Radar is the bomb, but my ears glaze over listening to it.

    For me, video is a good way to quickly get exposed to something, but to learn, I liked printed material with photos best.

    • chexclaim says

      September 8, 2014 at 12:45 pm

      I agree!

  12. carp says

    September 14, 2014 at 4:48 am

    This has been my favorite episode since Dave Vandenbout was on. I’m ok with what you guys release, but this one was relatively void of production and marketing bullshit. If only Charvat and Osmann had a podcast. …at least I’d learn something.

Trackbacks

  1. Latest Amp Hour: SDR meets RADAR | TriEmbed says:
    September 3, 2014 at 8:47 am

    […] This week on The Amp Hour Chris Gammel’s guests are Michael Ossman, the guy behind a (cheaper, simpler than previous, highly capable) software defined radio system and Greg Charvat, the guy behind a coffee can-based synthetic aperture radar system that uses your PC’s “sound card”. One of the most easy on the ears, interesting sharing between techies I’ve listened to in a good while.  For those interested in learning about SDR Michael has started a tutorial series. […]

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