What's this symbol (- capacitor with wire through the middle?)

If I'm looking at the correct symbol, that's a feed through capacitor.

They are common on RF devices where they allow wires to enter a shielded enclosure.

Looking at the picture from the link you gave here they are:

Those are known as "feed-through" capacitors.

They provide a way to get a wire into or out of a shielded enclosure - the capacitor gives some filtering to prevent unwanted signals from travelling along the wire.

You can see them where components/wires pass through the top and bottom sides of the small enclosure in the bottom view of the radio.

It looks like a feed through capacitor. The chassis is grounded and the wire passes from one side to the other to form a connection.