4 ms·

If you broadcast amateur radio, is it possible to 'hide' from enforcement? Are there mechanisms that an enforcement authority can use to find your physical loc

by niftich 10y ago

If you broadcast amateur radio, is it possible to 'hide' from enforcement? Are there mechanisms that an enforcement authority can use to find your physical location? Is it possible to ostensibly rebroadcast a government-approved channel, but with additional stenography or mixing to embed information?

toomuchtodo 10y ago
Depends on how long you're transmitting for. If you're transmitting to repeaters (which take in a signal on one frequency and rebroadcast on another), the time required to find you will go up. https://www.youtube.com/watch?v=QIGAOLJh-XE https://www.youtube.com/watch?v=QIGAOLJh-XE https://en.wikipedia.org/wiki/Amateur_radio_repeater https://en.wikipedia.org/wiki/Amateur_radio_repeater
Fej 10y ago
Law enforcement can triangulate ham radio signals. From what I understand it's relatively easy to do in the US.
- lightlyused 10y ago
  There used to be a remote FCC receive site near me. Looked like a fake pine tree. Only new about it because of a local broadcast engineer told me where it was.
LeoPanthera 10y ago
> Are there mechanisms that an enforcement authority can use to find your physical location? Yes, it's unimaginatively called "direction finding". Hams often do it as a sport, and sometimes to locate unlicensed operators causing interference. https://en.wikipedia.org/wiki/Amateur_radio_direction_finding https://en.wikipedia.org/wiki/Amateur_radio_direction_findin... > Is it possible to ostensibly rebroadcast a government-approved channel, but with additional stenography or mixing to embed information? Absolutely possible, though international amateur radio regulations prevent the concealing of information in a transmission.
wmf 10y ago
Tracking radio transmissions is pretty well established and is even a sport for some people. https://en.wikipedia.org/wiki/Amateur_radio_direction_finding https://en.wikipedia.org/wiki/Amateur_radio_direction_findin...
ShakataGaNai 10y ago
Hide? Not really. Triangulation is very trivial with the right equipment. All you need is two directional receivers that are separated a bit. Rotate each one until you get the strongest signal from the broadcaster you're looking for. Now draw two lines on the map based on those two directions and you've got your probable point of origin. You could do something like relay your signal - but your relay will be found. You could be on the move, but every time you broadcast you give away your location. I'm not sure about Turkey, but in the USA if you're a Ham, you had to supply your address to the FCC. So if the same is true in Turkey and the ham didn't lie... well they already know who you are and where you live.
- MichaelGG 10y ago
  Cell phones used to bypass the official international connections are popular in countries with stupid regulation. One guy in Honduras used to run a phone bank (IP->Honduras) out of a van. He'd drive around to avoid being triangulated. When you make 5+ cents a minute per 20kbps stream, all sorts of stuff becomes interesting.
deleted 10y ago
[deleted]
w8rbt 10y ago
Near Vertical Incident Skywave (NVIS) HF transmissions are very difficult (likely impossible) to track from the ground. They go almost straight up. Hams call them cloud burners. However, they are limited to 200 - 400 mile radius. https://en.wikipedia.org/wiki/Near_vertical_incidence_skywave https://en.wikipedia.org/wiki/Near_vertical_incidence_skywav... You'd need a dipole (14 AWG wire) about 5 meters above the ground or an 80 meter loop about 10 meters up. If setup right, the antenna would be difficult to detect as well. Edit: I'm a Ham. I build wire antennas as a hobby. It's fun.
- jdietrich 10y ago
  Earth-Moon-Earth or exotic digital modes are also a possibility. EME is impossible to triangulate if you're using a suitably directional antenna. A creative interpretation of the Shannon-Hartley theorem allows for communication below the noise floor using low symbol rates and wide bandwidth. LF and below is difficult to triangulate because of the huge wavelengths, but a workable antenna would be rather conspicuous. You might also get lucky with meteor scatter or sporadic E.
germinalphrase 10y ago
Not a HAM - but are their broadcasting devices that would fit in a car/motorcycle/bicycle that could be timed to switch between broadcasts on different devices in a random order for x amount of time (i.e. Radio A sends for 30 seconds, fades out as Radio B fades in with same message from a different, moving location)?

by niftich 10y ago

toomuchtodo 10y ago

Depends on how long you're transmitting for. If you're transmitting to repeaters (which take in a signal on one frequency and rebroadcast on another), the time required to find you will go up. https://www.youtube.com/watch?v=QIGAOLJh-XE https://www.youtube.com/watch?v=QIGAOLJh-XE https://en.wikipedia.org/wiki/Amateur_radio_repeater https://en.wikipedia.org/wiki/Amateur_radio_repeater

Fej 10y ago

Law enforcement can triangulate ham radio signals. From what I understand it's relatively easy to do in the US.

lightlyused 10y ago
There used to be a remote FCC receive site near me. Looked like a fake pine tree. Only new about it because of a local broadcast engineer told me where it was.

LeoPanthera 10y ago

> Are there mechanisms that an enforcement authority can use to find your physical location? Yes, it's unimaginatively called "direction finding". Hams often do it as a sport, and sometimes to locate unlicensed operators causing interference. https://en.wikipedia.org/wiki/Amateur_radio_direction_finding https://en.wikipedia.org/wiki/Amateur_radio_direction_findin... > Is it possible to ostensibly rebroadcast a government-approved channel, but with additional stenography or mixing to embed information? Absolutely possible, though international amateur radio regulations prevent the concealing of information in a transmission.

wmf 10y ago

Tracking radio transmissions is pretty well established and is even a sport for some people. https://en.wikipedia.org/wiki/Amateur_radio_direction_finding https://en.wikipedia.org/wiki/Amateur_radio_direction_findin...

ShakataGaNai 10y ago

Hide? Not really. Triangulation is very trivial with the right equipment. All you need is two directional receivers that are separated a bit. Rotate each one until you get the strongest signal from the broadcaster you're looking for. Now draw two lines on the map based on those two directions and you've got your probable point of origin. You could do something like relay your signal - but your relay will be found. You could be on the move, but every time you broadcast you give away your location. I'm not sure about Turkey, but in the USA if you're a Ham, you had to supply your address to the FCC. So if the same is true in Turkey and the ham didn't lie... well they already know who you are and where you live.

MichaelGG 10y ago
Cell phones used to bypass the official international connections are popular in countries with stupid regulation. One guy in Honduras used to run a phone bank (IP->Honduras) out of a van. He'd drive around to avoid being triangulated. When you make 5+ cents a minute per 20kbps stream, all sorts of stuff becomes interesting.

deleted 10y ago

[deleted]

w8rbt 10y ago

Near Vertical Incident Skywave (NVIS) HF transmissions are very difficult (likely impossible) to track from the ground. They go almost straight up. Hams call them cloud burners. However, they are limited to 200 - 400 mile radius. https://en.wikipedia.org/wiki/Near_vertical_incidence_skywave https://en.wikipedia.org/wiki/Near_vertical_incidence_skywav... You'd need a dipole (14 AWG wire) about 5 meters above the ground or an 80 meter loop about 10 meters up. If setup right, the antenna would be difficult to detect as well. Edit: I'm a Ham. I build wire antennas as a hobby. It's fun.

jdietrich 10y ago
Earth-Moon-Earth or exotic digital modes are also a possibility. EME is impossible to triangulate if you're using a suitably directional antenna. A creative interpretation of the Shannon-Hartley theorem allows for communication below the noise floor using low symbol rates and wide bandwidth. LF and below is difficult to triangulate because of the huge wavelengths, but a workable antenna would be rather conspicuous. You might also get lucky with meteor scatter or sporadic E.

germinalphrase 10y ago

Not a HAM - but are their broadcasting devices that would fit in a car/motorcycle/bicycle that could be timed to switch between broadcasts on different devices in a random order for x amount of time (i.e. Radio A sends for 30 seconds, fades out as Radio B fades in with same message from a different, moving location)?