Financial Markets Experience Shocking Confluence
In the United States, the proximity of major cities such as New York and Philadelphia, Baltimore and Philadelphia, Chicago and Milwaukee, Detroit and Cleveland, and Los Angeles and San Diego, creates unique dial layouts and adjacent spillover effects.
This phenomenon, known as adjacent spillover, occurs when full-power FM signals from different markets reach these regions with similar strength, causing interference or signal bleed-over. The northeastern U.S., particularly New Jersey, offers more opportunities for adjacent spillover due to tighter FM station spacings.
In the northeastern U.S., including central New Jersey, the FCC's Zones I and I-A apply. Two Class B FM stations in New Jersey, 94.5 WPST(FM) and 94.7 WXBK(FM), are approximately 58 miles apart, creating a close-quarters setup. Similarly, 103.3 WPRB(FM) in Princeton and 103.5 WKTU(FM) in New York form another such setup.
The Beltway area has a notorious short-spaced setup with 105.7 WJZ(FM) and 105.9 WMAL(FM) being approximately 48 miles apart. In certain areas of Mercer, Hunterdon, and Middlesex counties, the signals of New York City and Philadelphia FMs can be of equal strength.
The New York City and Philadelphia Class B FMs follow an 800 kHz separation pattern. However, there are several same-channel examples, such as 101.1 WCBS(FM) and 101.1 WBEB(FM).
In some locations, such as Plainsboro, N.J., the signals of New York City and Philadelphia FMs have predicted signal field strengths of about 60 dBuV/m, according to the Longley-Rice method. When a signal is 6 dB weaker than a first-adjacent FM signal, it becomes subject to adjacent spillover.
The adjacent spillover phenomenon was a motivation for the creation of the RadioLand app. With the aid of directional antennas, the coexistence of the two signals in short-spaced areas has been remarkable over the years.
The northeastern U.S., particularly New Jersey, has numerous grandfathered, short-spaced FM setups. A short drive on Interstate 83 separates the two areas where WJZ and WQXA are located, both being Class B stations. WJZ operates 47 miles from same-channel WQXA(FM) in York, Pa.
If you encounter locations where full-power signals collide, we encourage you to share them by emailing our website (our [email protected]). The DSP-generated selectivity of modern car radio tuners and portables improves signal reception, making it easier to navigate these challenging dial layouts.
[1] For more detailed information on adjacent spillover and its impact on specific regions, please refer to relevant studies and resources.
- The RadioLand app was inspired by the adjacent spillover phenomenon, as it helps improve signal reception in areas where full-power FM signals from different cities, like New York City and Philadelphia, collide.
- In the northeastern U.S., particularly New Jersey, the close proximity of Class B FM stations, such as WPST(FM) and WXBK(FM), can cause adjacent spillover due to their close quarters, even with an 800 kHz separation pattern.
- The use of directional antennas, combined with advancements in technology like DSP-generated selectivity in modern car radios, makes it easier to navigate challenging dial layouts affected by adjacent spillover effects in regions such as the northeastern United States.
