It's in Goldenrod City.
In the radio tower after you answer a quiz
You cant.
Goldenrod City Radio Tower.
goldenrod city.
first,you clear enmies and then ...
After beating team rocket at there warehouse and the radio tower at goldenrod city the director of the radio tower in goldenrod city will give the silver wing to you.
Just save the radio tower....you will get it as a reward.
The Kanto radio tower is in Lavender Town.
talk to guy in radio tower
go to the radio tower and talk everybody
get silver or rainbow wing in radio tower
get it from the radio tower in johto and go to the last one in the pokegear