Tuning a Dipole by Coiling

I have a dipole that’s 20m long (10m each side) strung through the house right to the banana plug adapter to the radio and no coax. I’ve coiled the wires together at the feed point to shorten and tune. I can run 40m with tuner turned off. I’m hitting Europe, Central America, Canada, and the midwest US.

I figure, since the wires are insulated and kept parallel to each other, the coil is serving as feed line and not part of the antenna.

See also