Does the LED on the receiver exclusively light up when the scalar signal is established?

The LED on the receiver only shows one thing conclusively.

That there is power transfer over the air. Enough power in fact to raise the voltage of the receiver coil to the point where it can illuminate the LED.

This can be done with a Scalar or EMF tune.

How the LED responds when you attempt to block the power transfer from the transmitter can give clues to whether you have a Scalar of EMF based tune.

Since scalar passes through everything, putting your hand in front of the receiver lid so as to intercept the transmission from the transmitter, should have little to no effect on the LED. If it is EMF tuned, your hand will absorb a large amount of energy from the transmitter affecting the LED significantly.

The link cable wire only carries current back to the transmitter from the receiver to provide a much easier common ground than the air would. In fact, it is not even needed, although tuning distances are incredibly short without it, given the amount of power that the transmitter is using.

Following the tuning process starting at 8 MHz and working your way down gives you the best chance at establishing a scalar field as it is the higher tuning point of the two resonant points found when working at standard 6 to 12 feet distances. Long haul tuning setups are completely different, and in fact, can be too far apart to establish an EMF based tuning anyhow.

The LED on the transmitter is to help you get into the zone, and the LED on the receiver is to help you finalize the tune. The LED on the receiver should remain off under normal operation to prevent power siphoning.

For more details, please check this link:
https://www.facebook.com/groups/spooky2scalar/posts/979508445956047/