NOTAM posted yesterday evening for KMDT Harrisburg shows that their ATC is apparently going deaf for 30 minutes on October 8 from 2030L to 2100L. But that's not the interesting thing. What caught my attention is that it affects...and shows...ALL their freqs, VHF and UHF.
VHF out of service will be 118.25 [per the FAA's FRQ_CSV file: Approach primary compass heading 001 degree to 79 degrees], 121.5, 121.7 [Ground primary], 124.1 [approach/departure primary 180 degrees to 309 degrees], 124.8 [tower primary], 126.45 [approach/departure primary 80 degrees to 179 degrees], and 128.075 [not listed. Spare?]
UHF out of service will be 243.0, 269.35 [per the FAA's FRQ_CSV file: tower primary], 269.45 [approach/departure primary 310 degrees to 79 degrees], 273.525 [approach/departure primary 211 degrees to 360 degrees], 281.525 [approach/departure primary 80 degrees to 179 degrees], 317.4 [not listed. Spare?], 348.6 [Ground primary].