Xiegu G1M Longer range coms on a budget

[Mortblanc]

Haven't you heard? The BBC can tap into your brain waves and tell when you are watching TV without a license!

More seriously, triangulation technology is as old as radio. When the Titanic sank they were sending transmissions hoping that someone would triangulate on their position. There were just too few receivers operating at that time.

One of the "secret" projects early in WW2 was recruiting civilian radio operators in England to track German signals and often triangulate the positions of their broadcasters. They actually got a draft exemption for their work.

That was the reason for "radio silence" during operations. They were afraid of giving away their position, not hiding what they were saying. The air force used triangulation to find home runways during inclement weather and the parachute troops had a form of triangulation they used to mark drop zones. Pathfinders went in and set up the transmitters in advance of the drops.

All of this 80 years ago during WW2.

So today you can track your teenager on your cell phone when he does not even have his phone turned on!