Sec.  87.149   Special requirements for automatic link establishment (ALE).

   Brief  signalling for the purposes of measuring the quality of a radio
   channel and thereafter establishing communication shall be permitted within
   the 2 MHz–30 MHz band. Public coast stations licensed under part 80 of this
   chapter providing high seas service are authorized by rule to use such
   signalling under the following conditions:

   (a) The transmitter power shall not exceed 100 W ERP;

   (b) Transmissions must sweep linearly in frequency at a rate of at least 60
   kHz per second, occupying any 3 kHz bandwidth for less than 50 milliseconds;

   (c) The transmitter shall scan the band no more than four times per hour;

   (d) Transmissions within 6 kHz of the following protected frequencies and
   frequency bands must not exceed 10  µW peak ERP:

   (1) Protected frequencies (kHz)
   2091.0 4188.0 6312.0  12290.0 16420.0
   2174.5 4207.5 8257.0  12392.0 16522.0
   2182.0 5000.0 8291.0  12520.0 16695.0
   2187.5 5167.5 8357.5  12563.0 16750.0
   2500.0 5680.0 8364.0  12577.0 16804.5
   3023.0 6215.0 8375.0  15000.0 20000.0
   4000.0 6268.0 8414.5  16000.0 25000.0
   4177.5 6282.0 10000.0        

   (2) Protected bands (kHz)

   4125.0–4128.0

   8376.25–8386.75

   13360.0–13410.0

   25500.0–25670.0

   (e) The instantaneous signal, which refers to the peak power that would be
   measured with the frequency sweep stopped, along with spurious emissions
   generated  from the sweeping signal, must be attenuated below the peak
   carrier power (in watts) as follows:

   (1)  On  any  frequency  more than 5 Hz from the instantaneous carrier
   frequency, at least 3 dB;

   (2)  On  any frequency more than 250 Hz from the instantaneous carrier
   frequency, at least 40 dB; and

   (3)  On any frequency more than 7.5 kHz from the instantaneous carrier
   frequency, at least 43 + 10log[10](peak power in watts) db.

   [ 62 FR 40308 , July 28, 1997]