§ 80.773   Co-channel interference protection.

   (a) Where a VHF public coast station geographic area licensee shares a
   frequency with an incumbent VHF public coast station licensee, the
   ratio of desired to undesired signal strengths must be at least 12 dB
   within the service area of the station.

   (b) Where a VHF public coast station geographic area licensee shares a
   frequency with an incumbent private land mobile radio licensee, the VHF
   public coast station geographic area licensee must provide at least 10
   dB protection to the PLMR incumbent's predicted 38 dBu signal level
   contour. The PLMR incumbent's predicted 38 dBu signal level contour is
   calculated using the F(50, 50) field strength chart for Channels 7-13
   in § 73.699 (Fig. 10a) of this chapter, with a 9 dB correction factor
   for antenna height differential, and is based on the licensee's
   authorized effective radiated power and antenna
   height-above-average-terrain.

   (c) VHF public coast station geographic area licensees are prohibited
   from exceeding a field strength of + 5 dBu (decibels referenced to 1
   microvolt per meter) at their service area boundaries, unless all the
   affected VHF public coast station geographic area licensees agree to
   the higher field strength.

   [ 63 FR 40065 , July 27, 1998, as amended at  64 FR 26887 , May 18, 1999]

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Subpart Q [Reserved]

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Subpart R—Technical Equipment Requirements for Cargo Vessels Not Subject to
Subpart W

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