Subchannels

The station's signal is multiplexed:

WSPX-TV started broadcasting in high definition in May 2010.

The channel 15 frequency was short-spaced to Belleville, Ontario's CBLFT-13 and was approved on the condition that the effective radiated power of the U.S. station not exceed 100 kilowatts.^[4]

According to WSPX-TV, an early reduction in analogue power and start of digital operation needed to take place months in advance of the February 17, 2009, FCC digital transition deadline to ensure that channel 15's antenna could be installed on the top of the tower in place of the existing channel 56 antenna before the onset of winter.^[5] UHF 56 was then left operational from a secondary, side-mounted antenna at a 25% reduction in coverage area until analogue shut-off.

Analog-to-digital conversion

WSPX-TV shut down its analog signal, over UHF channel 56, on June 12, 2009, the official date on which full-power television stations in the United States transitioned from analog to digital broadcasts under federal mandate. The station's digital signal remained on its pre-transition UHF channel 15,^[6] using virtual channel 56.