Where do you get the radio in goldenrod station Pokemon Heartgold DS?

You don't actually get a radio in Goldenrod City in Pokemon HeartGold. You receive the Radio Card from Mr. Pokemon inside the Goldenrod Department Store, which allows you to use the Radio feature on your Poketch.

Here's how to get it:

1. Enter the Goldenrod Department Store. You'll find it in the center of the city.

2. Head to the 3rd Floor. Go up the escalator and take a left.

3. Talk to Mr. Pokemon. He is standing near the back of the floor.

4. Receive the Radio Card. He will give it to you for free.

After receiving the Radio Card, you can access the Radio function on your Poketch by selecting the Radio icon. You can listen to music, check the weather forecast, and listen to news from different regions.