§ 15.233   Operation within the bands 43.71-44.49 MHz, 46.60-46.98 MHz,
48.75-49.51 MHz and 49.66-50.0 MHz.

   (a)  The  provisions  shown in this section are restricted to cordless
   telephones.

   (b) An intentional radiator used as part of a cordless telephone system
   shall operate centered on one or more of the following frequency pairs,
   subject to the following conditions:

   (1) Frequencies shall be paired as shown below, except that channel pairing
   for channels one through fifteen may be accomplished by pairing any of the
   fifteen  base  transmitter frequencies with any of the fifteen handset
   transmitter frequencies.

   (2) Cordless telephones operating on channels one through fifteen must:

   (i) Incorporate an automatic channel selection mechanism that will prevent
   establishment of a link on any occupied frequency; and

   (ii) The box or an instruction manual which is included within the box which
   the  individual  cordless  telephone  is  to be marketed shall contain
   information indicating that some cordless telephones operate at frequencies
   that may cause interference to nearby TVs and VCRs; to minimize or prevent
   such interference, the base of the cordless telephone should not be placed
   near or on top of a TV or VCR; and, if interference is experienced, moving
   the cordless telephone farther away from the TV or VCR will often reduce or
   eliminate the interference. A statement describing the means and procedures
   used  to  achieve automatic channel selection shall be provided in any
   application for equipment authorization of a cordless telephone operating on
   channels one through fifteen.
   Channel Base transmitter (MHz) Handset transmitter (MHz)
   1                       43.720                    48.760
   2                       43.740                    48.840
   3                       43.820                    48.860
   4                       43.840                    48.920
   5                       43.920                    49.020
   6                       43.960                    49.080
   7                       44.120                    49.100
   8                       44.160                    49.160
   9                       44.180                    49.200
   10                      44.200                    49.240
   11                      44.320                    49.280
   12                      44.360                    49.360
   13                      44.400                    49.400
   14                      44.460                    49.460
   15                      44.480                    49.500
   16                      46.610                    49.670
   17                      46.630                    49.845
   18                      46.670                    49.860
   19                      46.710                    49.770
   20                      46.730                    49.875
   21                      46.770                    49.830
   22                      46.830                    49.890
   23                      46.870                    49.930
   24                      46.930                    49.990
   25                      46.970                    49.970

   (c) The field strength of the fundamental emission shall not exceed 10,000
   microvolts/meter at 3 meters. The emission limit in this paragraph is based
   on measurement instrumentation employing an average detector. The provisions
   in § 15.35 for limiting peak emissions apply.

   (d) The fundamental emission shall be confined within a 20 kHz band and
   shall be centered on a carrier frequency shown above, as adjusted by the
   frequency tolerance of the transmitter at the time testing is performed.
   Modulation products outside of this 20 kHz band shall be attenuated at least
   26 dB below the level of the unmodulated carrier or to the general limits in
   § 15.209, whichever permits the higher emission levels. Emissions on any
   frequency more than 20 kHz removed from the center frequency shall consist
   solely of unwanted emissions and shall not exceed the general radiated
   emission  limits  in § 15.209. Tests to determine compliance with these
   requirements  shall  be performed using an appropriate input signal as
   prescribed in § 2.989 of this chapter.

   (e)  All emissions exceeding 20 microvolts/meter at 3 meters are to be
   reported in the application for certification.

   (f) If the device provides for the connection of external accessories,
   including external electrical input signals, the device must be tested with
   the accessories attached. The emission tests shall be performed with the
   device and accessories configured in a manner which tends to produce the
   maximum  level of emissions within the range of variations that can be
   expected under normal operating conditions.

   (g) The frequency tolerance of the carrier signal shall be maintained within
   ±0.01% of the operating frequency. The tolerance shall be maintained for a
   temperature variation of −20 degrees C to + 50 degrees C at normal supply
   voltage, and for variation in the primary voltage from 85% to 115% of the
   rated supply voltage at a temperature of 20 degrees C. For battery operated
   equipment, the equipment tests shall be performed using a new battery.

   (h) For cordless telephones that do not comply with § 15.214(d) of this part,
   the box or other package in which the individual cordless telephone is to be
   marketed shall carry a statement in a prominent location, visible to the
   buyer before purchase, which reads as follows:

   Notice: The base units of some cordless telephones may respond to other
   nearby units or to radio noise resulting in telephone calls being dialed
   through this unit without your knowledge and possibly calls being misbilled.
   In order to protect against such occurrences, this cordless telephone is
   provided with the following features: (to be completed by the responsible
   party).

   An application for certification of a cordless telephone shall specify the
   complete text of the statement that will be carried on the package and
   indicate where, specifically, it will be located on the carton.

   [ 54 FR 17714 , Apr. 25, 1989;  54 FR 32340 , Aug. 7, 1989, as amended at  56 FR 3785 , Jan. 31, 1991;  56 FR 5659 , Feb. 12, 1991;  60 FR 21985 , May 4, 1995]

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