Wizarding wireless is a close imitation of the Muggle wireless, and a wizarding wireless will even receive the same audio waves a Muggle wireless does. While the mechanisms for sending and receiving those waves are different, the radio waves themselves are the same, as evidenced by Muggle wireless listeners picking up the occasional wizarding program.
Muggle radio stations in the UK operate 100 megahertz apart. The magical stations in these areas operate 50 megahertz above and below each Muggle station. However, the close proximity of the stations increases the likelihood that a station may be overheard by Muggles. While Muggle radio stations in the United States all operate on the odd decimal frequencies, wizarding stations will operated on the even ones.
Muggles know the decision by the FCC to space all stations in the United States 200 megahertz apart as simply an arbitrary decision, but in truth, the original decision would have placed radio stations 100 megahertz apart, as in the UK. The MACUSA, noting the difficulties of keeping stations that were only 50 megahertz apart from being overheard by Muggles, planned accordingly, changing the FCC's regulations to require that all Muggle stations be kept 200 megahertz apart.
Ms. Nyx Bluestone, August 19th, 2015