Required minimum distance separation to TV facilities
Pursuant to § 73.825 of the Rules, Low Power FM stations operating on Reserved Band frequencies 88.1 through 91.9 (Channels 201 through 220) must provide protection to domestic TV stations on Channel 6 (82 to 88 MHz). The rules do not specify any protections to Channel 6 stations in Canada or Mexico.
Since the transition to digital television, the radio frequency (RF) channel that a TV station uses may be different than the "virtual" channel number that appears on TV sets and on over the air promotions and identity used by TV stations. LPFM stations are only required to protect TV facilities operating on RF Channel 6.
There are three methods of demonstrating protection.
Consent of the affected channel 6 station
LPFM stations that receive a letter of consent from the impacted channel 6 TV station can include that with their application in lieu of the distance or contour method shown below.
Distance separation method
LPFM stations must meet a specific distance from the channel 6 station. The distance will vary based on the frequency the LPFM station operates on and whether the TV station is a full-power or low-power station.
Contour method
LPFM stations that do not meet the distance separation method, can have an engineer or consultant perform a contour study. The contour study is based on the FM translator channel 6 protection rule §74.1205. Using the contour method, the LPFM station is assigned a specific interfering contour based on LPFM station channel. For no interference to occur, the appropriate interfering contour of the LPFM station cannot overlap the 47 dBu service contour of the Channel 6 TV station. Applicants using the contour method must specifically request a waiver of §73.825 citing the LPFM Tech Order. Notification must be sent to the impacted TV station. While they are not required to concur with the request, they do have an opportunity to object to the application.
LPFM stations using the contour method may also utilize a directional antenna to demonstrate protection. Channel 6 protection is not considered an exempt use under the §73.316 antenna rule and therefore a proof of performance or computer modeling as well as verification from a surveyor and certification from the antenna installer is required.
Distance separation and contour chart
| FM Channel | FM Frequency | Minimum distance to full-power TV stations | Minimum distance to low-power TV (LPTV), Class A, TV translator or digital replacement translator | LPFM station interfering contour when using the contour method |
|---|---|---|---|---|
| 201 | 88.1 | 138 km (85.8 miles) | 98 km (60.9 miles) | 54 dBu |
| 202 | 88.3 | 137 km (85.1 miles) | 97 km (60.3 miles) | 56 dBu |
| 203 | 88.5 | 136 km (84.5 miles) | 95 km (59.0 miles) | 59 dBu |
| 204 | 88.7 | 135 km (83.9 miles) | 94 km (58.4 miles) | 62 dBu |
| 205 | 88.9 | 135 km (83.9 miles) | 93 km (57.8 miles) | 64 dBu |
| 206 | 89.1 | 133 km (82.6 miles) | 91 km (56.5 miles) | 69 dBu |
| 207 | 89.3 | 133 km (82.6 miles) | 91 km (56.5 miles) | 73 dBu |
| 208 | 89.5 | 133 km (82.6 miles) | 91 km (56.5 miles) | 73 dBu |
| 209 | 89.7 | 133 km (82.6 miles) | 91 km (56.5 miles) | 73 dBu |
| 210 | 89.9 | 133 km (82.6 miles) | 91 km (56.5 miles) | 73 dBu |
| 211 | 90.1 | 133 km (82.6 miles) | 91 km (56.5 miles) | 73 dBu |
| 212 | 90.3 | 132 km (82.0 miles) | 90 km (55.9 miles) | 74 dBu |
| 213 | 90.5 | 132 km (82.0 miles) | 90 km (55.9 miles) | 75 dBu |
| 214 | 90.7 | 132 km (82.0 miles) | 90 km (55.9 miles) | 77 dBu |
| 215 | 90.9 | 131 km (81.4 miles) | 90 km (55.9 miles) | 78 dBu |
| 216 | 91.1 | 131 km (81.4 miles) | 89 km (55.3 miles) | 80 dBu |
| 217 | 91.3 | 131 km (81.4 miles) | 89 km (55.3 miles) | 81 dBu |
| 218 | 91.5 | 131 km (81.4 miles) | 89 km (55.3 miles) | 85 dBu |
| 219 | 91.7 | 130 km (80.8 miles) | 89 km (55.3 miles) | 88 dBu |
| 220 | 91.9 | 130 km (80.8 miles) | 89 km (55.3 miles) | 90 dBu |