§  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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