How do I power up the radio transmitter?

I'm on the "Taking Independence" mission with the Minutemen and now I need to power the radio transmitter. I already built a generator, but that doesn't seem to be enough, I need to connect it somehow.

How exactly do I connect the generator to the transmitter? The various electricity items I can build in the Workshop aren't really explained.

Solution 1:

Step by Step, no pics

1. Build a small generator (skip if you have an existing with spare power)
2. While in workshop mode still, press SPACE (Y on XB, Triangle on PS4) while highlighting the generator. (it should now show a little wire from generator to your cursor that moves around with you)
3. Highlight the Radio Tower, and press SPACE(Y on XB, Triangle on PS4) again.

Bam! Transmission begins.

Solution 2:

You build a generator and then power cables from the generator to the radio.

You create wires by pointing at an electrical object and pressing the button highlighted for Attach Wire: