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Author Topic: Direction finding of a skywave signal  (Read 292 times)

Offline OgreVorbis

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Direction finding of a skywave signal
« on: October 29, 2019, 0906 UTC »
With all the shortwave pirates here, I am curious about how easy it is for the FCC to direction find a skywave signal. I would assume it is much harder than for VHF bands. Is it really even practical to do on a vehicle?
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Offline Brian

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Re: Direction finding of a skywave signal
« Reply #1 on: October 29, 2019, 0935 UTC »
They can probably get a bearing on it. Then they just have to get within groundwave to get your location.
I know that the authorities have traced me to about 10 miles of my location purely on skywave  :( Thankfully, where I live they not bothered about me.

Offline OgreVorbis

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Re: Direction finding of a skywave signal
« Reply #2 on: October 29, 2019, 1005 UTC »
They can probably get a bearing on it. Then they just have to get within groundwave to get your location.
I know that the authorities have traced me to about 10 miles of my location purely on skywave  :( Thankfully, where I live they not bothered about me.

It seems that on the lower HF bands, the groundwave doesn't meet the skywave. There is a large ring of no reception surrounding the groundwave. Have you noticed this? This is probably even more significant with horizontal antennas like the inverted V. A good reason to not use a vertical antenna.
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Offline Josh

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Re: Direction finding of a skywave signal
« Reply #3 on: October 29, 2019, 2232 UTC »
Iono how they do it for certain right now as my info's dated but the fcc can find pretty much anything that hits their ears. No more goniometers or FLR9s, nowadays it's just a few short active monopoles in a straight line a few yards long that feed an sdr, of course each fcc outlet will be listening on channel too. Their mobiles have a fake plastic roof with embedded wire antenna array for df, they can approximate the power output too. The nsa just records and timestamps everything in bulk so they can tdoa anything sexy after the fact.
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Offline ChrisSmolinski

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Re: Direction finding of a skywave signal
« Reply #4 on: October 30, 2019, 1033 UTC »
FCC Seeks Telecommunications Specialist

10/29/2019

The FCC is looking for a telecommunications specialist to work at the HF
Direction Finding Center in Columbia, Maryland. This is a full-time
position with a competitive salary.

The incumbent would perform “watch duty” and serve as a technical
authority, providing technical assistance and guidance to communication
systems users to resolve radio interference complaints and problems.

The telecommunications specialist collects radio signal analysis
information using equipment deployed throughout the US to collect,
correlate, and analyze characteristics of radio signals involved in
interference problems, distress, or safety-related signals, or other radio
signals involved in other high-priority activities, such as law enforcement
or national defense.

This individual analyzes complaints, inquires, and comments from multiple
sources; investigates compliances with FCC rules and regulations, and
determines appropriate actions, utilizing the FCC’s remote HF network of
radio direction finders and radio signal analysis equipment.

For additional information, see the full job description: https://www.usajobs.gov/GetJob/ViewDetails/550061100

http://www.arrl.org/news/view/fcc-seeks-telecommunications-specialist-1?fbclid=IwAR1fWomOlDUycyBH5-YR-Om-4oSi4GNexsOTHMFF_kxTAflA1hu94hCjQVw

Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
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