§  90.237   Interim provisions for operation of radioteleprinter and
radiofacsimile devices.

   These provisions authorize and govern the use of radioteleprinter and
   radiofacsimile devices for base station use (other than on mobile-only
   or paging-only frequencies) in all radio pools and services except
   Radiolocation in this part.

   (a) Information must be submitted with an application to establish that
   the minimum separation between a proposed radioteleprinter or
   radiofacsimile base station and the nearest co-channel base station of
   another licensee operating a voice system is 120 km (75 mi) for a
   single frequency mode of operation, or 56 km (35 mi) for two frequency
   mode of operation. Where this minimum mileage separation cannot be
   achieved, either agreement to the use of F1B, F2B, F3C, G1B, G2B or G3C
   emission must be received from all existing co-channel licensees using
   voice emission within the applicable mileage limits, or if agreement
   was not received, the licensee of the radioteleprinter or
   radiofacsimile system is responsible for eliminating any interference
   with preexisting voice operations. New licensees of voice operations
   will be expected to share equally any frequency occupied by established
   radioteleprinter or radiofacsimile operations.

   (b) [Reserved]

   (c) Transmitters certificated under this part for use of G3E or F3E
   emission may also be used for F1B, F2B, F3C, G1B, G2B or G3C emission
   for radioteleprinter or radiofacsimile, provided the keying signal is
   passed through the low pass audio frequency filter required for G3E or
   F3E emission. The transmitter must be so adjusted and operated that the
   instantaneous frequency deviation does not exceed the maximum value
   allowed for G3E or F3E.

   (d) Frequencies will not be assigned exclusively for F1B, F2B, F3C,
   G1B, G2B or G3C emission for radioteleprinter or radiofacsimile (except
   where specifically provided for in the frequency limitations).

   (e) The requirements in this part applicable to the use of G3E or F3E
   emission are also applicable to the use of F1B, F2B, F3C, G1B, G2B or
   G3C emission for radioteleprinter and radiofacsimile transmissions.

   (f) The station identification required by § 90.425 must be given by
   voice or Morse code.

   (g) For single sideband operations in accordance with § 90.266,
   transmitters certified under this part for use of J3E emission may also
   be used for A2B and F2B emissions for radioteleprinter transmissions.
   Transmitters certified under this part for use of J3E emission in
   accordance with § § 90.35(c)(1)(A), 90.35(c)(1)(B), 90.35(c)(1)(C) and
   90.257(a) may also be used for A1B, A2B, F1B, F2B, J2B, and A3C
   emissions to provide standby backup circuits for operational
   telecommunications circuits which have been disrupted, where so
   authorized in other sections of this part.

   [ 43 FR 54791 , Nov. 22, 1978, as amended at  49 FR 48712 , Dec. 14, 1984;
    51 FR 14998 , Apr. 22, 1986;  62 FR 18927 , Apr. 17, 1997;  63 FR 36610 ,
   July 7, 1998;  63 FR 68965 , Dec. 14, 1998;  72 FR 35195 , June 27, 2007]