FCC 2.1055 Revised as of October 1, 2014
Goto Year:2013 |
2015
§ 2.1055 Measurements required: Frequency stability.
(a) The frequency stability shall be measured with variation of ambient
temperature as follows:
(1) From -30DEG to +50DEG centigrade for all equipment except that
specified in paragraphs (a) (2) and (3) of this section.
(2) From -20DEG to +50DEG centigrade for equipment to be licensed for
use in the Maritime Services under part 80 of this chapter, except for
Class A, B, and S Emergency Position Indicating Radiobeacons (EPIRBS),
and equipment to be licensed for use above 952 MHz at operational fixed
stations in all services, stations in the Local Television Transmission
Service and Point-to-Point Microwave Radio Service under part 21 of
this chapter, equipment licensed for use aboard aircraft in the
Aviation Services under part 87 of this chapter, and equipment
authorized for use in the Family Radio Service under part 95 of this
chapter.
(3) From 0DEG to +50DEG centigrade for equipment to be licensed for use
in the Radio Broadcast Services under part 73 of this chapter.
(b) Frequency measurements shall be made at the extremes of the
specified temperature range and at intervals of not more than 10DEG
centigrade through the range. A period of time sufficient to stabilize
all of the components of the oscillator circuit at each temperature
level shall be allowed prior to frequency measurement. The short term
transient effects on the frequency of the transmitter due to keying
(except for broadcast transmitters) and any heating element cycling
normally occurring at each ambient temperature level also shall be
shown. Only the portion or portions of the transmitter containing the
frequency determining and stabilizing circuitry need be subjected to
the temperature variation test.
(c) In addition to all other requirements of this section, the
following information is required for equipment incorporating heater
type crystal oscillators to be used in mobile stations, for which type
acceptance is first requested after March 25, 1974, except for battery
powered, hand carried, portable equipment having less than 3 watts mean
output power.
(1) Measurement data showing variation in transmitter output frequency
from a cold start and the elapsed time necessary for the frequency to
stabilize within the applicable tolerance. Tests shall be made after
temperature stabilization at each of the ambient temperature levels;
the lower temperature limit, 0DEG centigrade and +30DEG centigrade with
no primary power applied.
(2) Beginning at each temperature level specified in paragraph (c)(1)
of this section, the frequency shall be measured within one minute
after application of primary power to the transmitter and at intervals
of no more than one minute thereafter until ten minutes have elapsed or
until sufficient measurements are obtained to indicate clearly that the
frequency has stabilized within the applicable tolerance, whichever
time period is greater. During each test, the ambient temperature shall
not be allowed to rise more than 10DEG centigrade above the respective
beginning ambient temperature level.
(3) The elapsed time necessary for the frequency to stabilize within
the applicable tolerance from each beginning ambient temperature level
as determined from the tests specified in this paragraph shall be
specified in the instruction book for the transmitter furnished to the
user.
(4) When it is impracticable to subject the complete transmitter to
this test because of its physical dimensions or power rating, only its
frequency determining and stabilizing portions need be tested.
(d) The frequency stability shall be measured with variation of primary
supply voltage as follows:
(1) Vary primary supply voltage from 85 to 115 percent of the nominal
value for other than hand carried battery equipment.
(2) For hand carried, battery powered equipment, reduce primary supply
voltage to the battery operating end point which shall be specified by
the manufacturer.
(3) The supply voltage shall be measured at the input to the cable
normally provided with the equipment, or at the power supply terminals
if cables are not normally provided. Effects on frequency of
transmitter keying (except for broadcast transmitters) and any heating
element cycling at the nominal supply voltage and at each extreme also
shall be shown.
(e) When deemed necessary, the Commission may require tests of
frequency stability under conditions in addition to those specifically
set out in paragraphs (a), (b), (c), and (d) of this section. (For
example measurements showing the effect of proximity to large metal
objects, or of various types of antennas, may be required for portable
equipment.)
[ 39 FR 5919 , Feb. 14, 1974, as amended at 51 FR 31304 , Sept. 2, 1986;
56 FR 11682 , Mar. 20, 1991. Redesignated at 63 FR 36599 , July 7, 1998.
68 FR 68545 , Dec. 9, 2003]
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