The phrase "a signal back" is correct and usable in written English.
It can be used when referring to a response or indication sent in return, often in communication contexts.
Example: "After sending the initial message, I waited for a signal back to confirm they received it."
Alternatives: "a response back" or "a reply back".
Then that beacon sends a signal back to the fob, causing the fob to beep like a Geiger counter.
They send a signal back to one of Neul's base stations, which are being attached by BT to masts and street lamps.
Well, that's further out than Mercury, and we had no problem getting a signal back from there with technology from the 1970s.
When hit by a plane's radar signal, though, the radio tags send a signal back with additional information that identifies the equipment or person.
Its bins will use ultrasound, bouncing sound waves across the top levels of the container to detect rubbish, and sending a signal back to base when full.
A minute after that, it will start tumbling through the increasingly dense clouds of gas and will lose the ability to send a signal back to Earth.
So to make Raman spectroscopy work on a distant target, researchers would need an enormously powerful laser to get a detectable signal back.
Tesla's new Autopilot can also bounce its radar signal off of the roadway or its surroundings and receive an echo signal back to provide a view around any cars you're driving behind, which means it should have "superhuman" object detection abilities, according to Musk.
He searches through his laptop, checks the disturbance and sends a telephone signal back to the computer aboard the windmill.
If the data indicated abnormally frequent bladder emptying, which happened when animals received the molecule cyclophosphamide (not shown), the external device transmitted a wireless signal back to the base station that caused the LEDs to turn on.
UEs transmit a pilot signal back to eNB using the uplink pilot time slot.
