Do balanced charges propagate electrónic waves? Two charges with different signs neutralize each other and do not generate an electric field when they are joined. Free electrons inside a conductor are balanced (as a whole) with the positive charge of the lattice.
Accelerated charges propagate electromagnetic waves.
Is the latter true only for separated charges, such as surface charge, or is it also true for electrons inside a conductor despite being balanced?
 A: This can be a bit tricky. People make the mistake of focusing too much on electrons. What is important is the charge density and the current density. In order to get electromagnetic waves you need to have a charge or current density that has a changing dipole moment.
Example 1: isolated charge moving at uniform velocity. This does not produce an EM wave because the charge and current dipole moments are both not changing.
Example 2: isolated charge moving with uniform circular motion. This produces an EM wave because the current dipole moments is rotating as the charge goes around the loop. The charge dipole moment is merely moving as in Example 1.
Example 3: loop with steady current. This does not produce an EM wave because the current dipole moment is steady and the charge dipole moment is zero. Note that the electrons in the wire are still accelerating as in Example 2. Note also that this case matches the specifications of your question, at all points the charge is balanced so there is no charge density anywhere, only current density. Charges are accelerating but there is no wave.
Example 4: loop with oscillating current. This does produce an EM wave because the current dipole moment is oscillating while the charge dipole moment is zero. Note that this case again matches the specifications of your question. At all points the charge is balanced so there is no charge density anywhere, only current density. Charges are accelerating and there is a wave.
Example 5: straight wire segment with oscillating current. This does produce an EM wave because both the current and charge dipole moments are changing in time. The charge is not always neutralized.
