Sec.  74.793   Digital low power TV and TV translator station protection of
broadcast stations.

   (a) An application to construct a new digital low power TV or TV translator
   station or change the facilities of an existing station will not be accepted
   if it fails to meet the interference protection requirements in this
   section.

   (b) Except as provided in this section, interference prediction analysis is
   based on the interference thresholds (D/U signal strength ratios) and other
   criteria and methods specified in  Sec. 73.623(c)(2) through (c)(4) of this
   chapter. Predictions of interference to co-channel DTV broadcast, digital
   Class A TV, digital LPTV and digital TV translator stations will be based on
   the interference thresholds specified therein for “DTV-into-DTV.”
   Predictions of interference to co-channel TV broadcast, Class A TV, LPTV and
   TV translator stations will be based on the interference threshold specified
   for “DTV-into-analog TV.” Predictions of interference to TV broadcast, Class
   A TV, LPTV and TV translator stations with the following channel
   relationships to a digital channel will be based on the threshold values
   specified for “Other Adjacent Channels (Channels 14–69 only),” where N is
   the analog channel: N–2, N+2, N–3, N+3, N–4, N+4, N–7 , N+7, N–8, N+8, N+14,
   and N+15.

   (c) The following D/U signal strength ratios (dB) shall apply to the
   protection of stations on the first adjacent channel. The D/U ratios for
   “Digital TV-into-analog TV” shall apply to the protection of TV broadcast,
   Class A TV, LPTV and TV translator stations. The D/U ratios for “Digital
   TV-into-digital TV” shall apply to the protection of DTV, digital Class A
   TV, digital LPTV and digital TV translator stations. The D/U ratios
   correspond to the digital LPTV or TV translator station's specified
   out-of-channel emission mask.


------------------------------------------------------------------------
                                                   Simple     Stringent
                                                    mask         mask
------------------------------------------------------------------------
Digital TV-into-analog TV.....................           10            0
Digital TV-into-digital TV....................           -7          -12
------------------------------------------------------------------------

   (d) For analysis of predicted interference from digital low power TV and TV
   translator stations, the relative field strength values of the assumed
   antenna vertical radiation pattern in Table 8 in OET Bulletin 69 shall be
   doubled up to a value of 1.0.

   (e) Protection to the authorized facilities of DTV broadcast stations shall
   be based on not causing predicted interference to the population within the
   service area defined and described in  Sec. 73.622(e) of this chapter, except
   that a digital low power TV or TV translator station must not cause a loss
   of service to 0.5 percent or more of the population predicted to receive
   service from the authorized DTV facilities.

   (f) Protection to the authorized facilities of TV broadcast stations shall
   be based on not causing predicted interference to the population within the
   Grade B field strength contours defined and described in  Sec. 73.683 of this
   chapter, except that a digital low power TV or TV translator station must
   not cause a loss of service to 0.5 percent or more of the population
   predicted to receive service from the authorized TV broadcast facilities.

   (g) Protection to the authorized facilities of Class A and digital Class A
   TV stations shall be based on not causing predicted interference to the
   population within the service area defined and described in  Sec. 73.6010 (a)
   through (d) of this chapter, respectively, except that a digital low power
   TV or TV translator station must not cause a loss of service to 0.5 percent
   or more of the population predicted to receive service from the authorized
   Class A TV or digital Class A TV facilities.

   (h) Protection to the authorized facilities of low power TV and TV
   translator stations and digital low power TV and TV translator stations
   shall be based on not causing predicted interference to the population
   within the service area defined and described in  Sec.  Sec. 74.707(a) and 74.792,
   respectively, except that a digital low power TV or TV translator station
   must not cause a loss of service to 2.0 percent or more of the population
   predicted to receive service from the authorized low power TV, TV
   translator, digital low power TV or digital TV translator station.

   [ 69 FR 69335 , Nov. 29, 2004]