WIFI DFing

[Martin]

I believe the wifi receiver approach is better but it could still be done
with a radio.

I just tried a HackRF/rubber ducky/waterfall spectrum analyzer application
and was able to locate my AP/extenders using body blocking technique.
There's enough amplitude variation on the waterfall to fingerprint
different stations on the same frequency.  I didn't have time to reproduce
it using the audio clicks but I think it could work as well.  Body blocking
works great at those frequencies so I don't think a directional antenna
would be needed.  I'm going try it later with my Alpha card.  Maybe we can
put a new spin on an old fad - AP hunting.

73 Martin W6MRR

On Wed, Mar 20, 2019 at 3:36 PM Terry N4TLF <n4tlf at wb4jfi.com> wrote:

> It is possible to DF if you have a good directional antenna, a wifi device
> that allows an external antenna, and you can program a version of DD-WRT
> (IIRC) into the device.  I have used both a beam and a dish to peak on
> specific wifi signals.  It helps to know what channel the wifi in question
> is on, and even better the SSID.  It’s been a while, but there is a mode in
> DD-WRT, or the HSMM/BBHN/AREDN firmware that shows you the SSIDs out there
> on what channels, and I think you can get signal strength, albeit slowly.
> Or, use the software that Jacek mentions.
>
> You can also use an old satellite TV antenna, with a modified feed in
> place of the original feed/LNB combo.  There are a LOT of instructions on
> how to modify them.  Realize that these antennas use an offset feed, so
> don’t “point” the antenna without taking that into account.
>
> I have had good luck with both the Amazon wifi beam antennas ($25?), and
> the $50 parabolic dish on Amazon.  Mel (W4MEL) and I were using these to
> build a AREDN link between our two houses, as well as trying to get others
> interested in AREDN/BBHN here in Charleston a couple of years ago.
> Unfortunately, there are not enough hams or high places here to make an
> AREDN network viable.
> 73, Terry, N4TLF
>
> *From:* Jacek Radzikowski
> *Sent:* Wednesday, March 20, 2019 6:06 PM
> *To:* Martin
> *Cc:* tacos ; Alex Fraser
> *Subject:* Re: WIFI DFing
>
> Using regular radio for DFing a wifi transmitter is not such a good idea.
> The channels overlap, higher data rate transmissions use spectrum spanning
> several channels, and many stations transmit on the same frequency, so with
> a plain received you will hear a cacophony of sounds, making it almost
> impossible to find the station you're looking for.
> You will get much better results using a good wifi card with SMA connector
> (Alfa cards are great for 2.4G band) with a directional external antenna
> and airmon-ng from Aircrack-ng package to monitor signal strength for the
> station you are interested in.
> Don't buy those cheap 2.4G yagis from ebay or amazon. They are junk.
> You'll get much better results with a home-made cantenna, orheck Andrew
> Mcneil's channel on youtube if you need some inspiration:
> https://www.youtube.com/channel/UCHqwzhcFOsoFFh33Uy8rAgQ
>
> Regards,
> Jacek
> kw4ep
>
> On Wed, Mar 20, 2019 at 5:18 PM Martin <dcmk1mr2 at gmail.com> wrote:
>
>> WiFi features short packets.  You can tune in on an access point and hear
>> the clicks.  You could try with a highly directional yagi or time of
>> arrival rig.
>>
>> BTW Transmitter Hunting
>> <https://www.amazon.com/Transmitter-Hunting-Direction-Finding-Simplified/dp/0830627014/ref=asc_df_0830627014/?tag=hyprod-20&linkCode=df0&hvadid=312126345020&hvpos=1o1&hvnetw=g&hvrand=18402996747497945190&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9032081&hvtargid=pla-569092361693&psc=1>
>> is highly recommended but is mostly VHF.
>>
>> 73 Martin W6MRR
>>
>>
>> On Wed, Mar 20, 2019 at 1:55 PM Alex Fraser <beatnic at comcast.net> wrote:
>>
>>> Is it possible to find a WIFI station with direction finding?
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>
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