HackRF One SDR as a Spectrum Analyzer

Discussion in 'Wireless & RF Design' started by BillJames, Apr 26, 2019.

  1. BillJames

    Thread Starter New Member

    Jul 3, 2015
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    Has anyone used a HackRF One software defined radio as a spectrum analyzer? If so what SDR software did you use and how did it perform. My application is to do RF audits within homes/offices. Typical RF energy sources are microwave ovens (2.4GHz), wifi routers (2.4GHz/5 GHz), Cell phones, etc. Most spectrum analyzers that go up to 5GHz are somewhat expensive. The HackRF One is an amazing SDR that works up to 6GHz and costs about $300. Here's a link to the developer's site: https://greatscottgadgets.com/hackrf/one/
     
  2. nsaspook

    AAC Fanatic!

    Aug 27, 2009
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  3. dendad

    Distinguished Member

    Feb 20, 2016
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    yes, try a cheap TV tuner first to see how it works. A lot will depend on if you want an indication or a calibrated measuring device.
     
  4. BillJames

    Thread Starter New Member

    Jul 3, 2015
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    NSASpook & Dendad - Thanks for the input and the links. I'll consider the dongle to get started, but it only goes up to 1.8GHz. The reason I was considering the HackRF One is that it goes up to 6GHz.
     
  5. nsaspook

    AAC Fanatic!

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    For a cheap wideband RF monitor it looks pretty neat.
     
  6. Janis59

    Active Member

    Aug 21, 2017
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    RE: NSASpook
    How did You managed the main terrible SDA trouble - that only possible way to scan all range from MHz to GHz is possible by "drag it", thus the fastest is hour. I dont know any soft able for expanding a range let in one screen stays compressed all frequencies.
    RE: BillJames
    Yes, HackRF1 is superior instrument. BUT, it gives only relative values instead of absolute, however home owners are interested to know the absolute figures (is normative overstepped or not). Thus I am using a cheap-end 3-axis "ball-head" device for measuring and SDA only for research what is the reason of situation.
    RE: both
    Cannot stand to keep silent and ask the full scale dumb question - did You cached that around high power radio towers, near zone are very high A/m figures, instead after of some 1/2 km to 1 km prevalates the V/m and practically rare and only for small transmitters the W/m2 are overstepped. So, why it not coresponds to Ohm`s law V/m divide to A/m get 377 Ohms. More over, why them are not com-passed with brilliant theoretical formula V/m*A/m=W/m2 ?? Never come in pass. And difference may happen even 10 or 100 fold. More over - what is the effect that I am making step forward and it shows say 100 V/m 0,2 A/m 1 W/m2 , step another step forward and it shows 20 V/m 0,01 A/m and 0,001 W/m2, step one more forward and get the 500 V/m 1 A/m and 50 W/m2. Cant it be that free air impedance is so shaky, no! Interferences? From where if 400m high tower stands 400m afar and nearest object except tiny bushes and grass are 1 km afar. I am applying in such situations the highest values yet never I may swear it is correct to do so.
     
  7. nsaspook

    AAC Fanatic!

    Aug 27, 2009
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    I've got other equipment to compare the SDR sweep scans with so it's OK for a general 'bug' detector. Every conventional SA has bandwidth limitations that result in frequency resolution constraints at high frequency sweep ranges.
    [​IMG]
    LC sweep response.
    [​IMG]
    [​IMG]
    SDR sweep no antenna.
    [​IMG]

    SDR with far-field antenna.
    [​IMG]
     
  8. Janis59

    Active Member

    Aug 21, 2017
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    What is this Holy Crap?? Why at least the graph form is not the same?? It cannot be Fourier answering the probable court-case.

    Probably, and I much believe it may be this case You tell about, I have wrote here about similar problem with my new antennoscope few weeks ago, just the CABLE produces a multiple resonances for any frequencies at what the product of impedance is not 50 Ohm, I mean the load. Thus, my solution was to cut cabling at equally lambda long thus at least one most interesting freq have no reflections in cable. The picture changed as day out of night with my freq analyzer, so I begun to realize what happens in the system after days of troubleshooting.
     
    Last edited: May 1, 2019
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