Software Defined Radio Direction Finding (SDRDF)

How to do Radio Direction Finding with a Software Defined Radio (USRP/GNU Radio)
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More information: http://wiki.spench.net/wiki/SDRDF

All non-original diagrams and pictures are used with fair use rationale for educational purposes.

"Transmitter hunting: radio direction finding simplified" By Joseph D. Moell, Thomas N. Curlee
http://books.google.com.au/books?id=R...

http://silcom.com/~pelican2/PicoDopp/...

http://en.wikipedia.org/wiki/Directio...
http://en.wikipedia.org/wiki/SIGINT
http://en.wikipedia.org/wiki/Adcock_a...
http://en.wikipedia.org/wiki/Y-stations

• Category

  Science & Technology

[FirstToken]

At video time 02:20 "DUFF DUFF". Is this an Australian thing? I believe most places (at least most English/American speaking that I have dealt with) use the term HUFF DUFF for HF DF, but I don't think I have ever heard DUFF DUFF applied before.

[balint256]

Not specifically an Australian thing - more a variation on a theme for the higher frequencies. Should be said with great enthusiasm and conviction! There's always a first :)

[pspheaven]

Cool but it seems like it'd be easier to just get a conventional Ramsey kit

[mistertentpole]

could you calculate bearing AND distance if you know the transmitter wattage and antenna type?

[Mattypoppins]

Balint (VK2FUNK), myself (VK2TVK) and Nick (VK2DAP) were out getting dinner in Newtown, Sydney, when Balint and myself started discussing RDF and how the doppler could work in SDR. While we were talking about how to switch the antennas, Nick loudly proclaimed "HUFF DUFF!" in an enthusiastic voice. It stuck, however, because we were doing it on VHF/UHF (specifically UHF CB and GRN band) we dropped the HF part and it became DUFF DUFF. And yes, it must be proclaimed loudly in a boisterous voice!

[balint256]

You're definitely on the right track ;) It would be (theoretically) exactly as you describe: additional hardware would be necessary to divide the master clock down to a suitable rate for the antenna switch - and the rest is done in software!

[Roy Cohen]

But I know nothing about RF so I could just be terribly mistaken haha

[Roy Cohen]

maybe breaking out the oscillators pins on the dongle and then feeding those into some signal processing to be able to switch the antennas at the same clock as the cheap radio module.

[Roy Cohen]

Hmm would there be a way to use the realtek 20 dollar dongle to do this if you could somehow get the clock out of it and into the switch? or does it just not have enough power for that.