WDCA-DT (UPN) service has been operating under Digital Special Temporary Authority (STA) until they are ready to go full-power. This will require FOX5/UPN20 engineers to move their DTV antenna to a new tower. Currently they are running low-power (1.172 kW) and their DTV antenna is extremely low (146.1 m HAAT). Compare UPN20 to the other DC area stations and you'll see why very few people can receive them.
FYI, the engineers at FOX5/UPN20 are making plan to move WDCA-DT and go full-power as early as July. However, there is no official word so don't be surprised if this doesn't happen. Anyway, when this happens their DTV antenna will be almost twice as high and their digital signal will be over 400X more powerful.
This is not a VOOM problem.
WETA-DT 27 DT LIC DC US 75. kW 177. m
WETA-DT 27 DT CP DC US 90. kW 254. m
WHUT-DT 33 DT CP MOD DC US 100. kW 254. m
WUSA-DT 34 DT LIC DC US 1000. kW 254. m
WDCA-DT 35 DS STA DC US 1.172 kW 146.1 m
WDCA-DT 35 DT CP MOD DC US 500. kW 254. m
WTTG-DT 36 DT LIC DC US 1000. kW 201. m
WJLA-DT 39 DT LIC DC US 646. kW 254. m
WJLA-DT 39 DT CP DC US 1000. kW 254. m
WRC-DT 48 DT LIC DC US 813. kW 242. m
WBDC-DT 51 DT LIC DC US 125. kW 252.5 m