[Code of Federal Regulations] [Title 47, Volume 2] [Revised as of October 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 47CFR24.135] [Page 236] TITLE 47--TELECOMMUNICATION CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) PART 24--PERSONAL COMMUNICATIONS SERVICES--Table of Contents Subpart D--Narrowband PCS Sec. 24.135 Frequency stability. (a) The frequency stability of the transmitter shall be maintained within [plusmn] 0.0001 percent ([plusmn] 1 ppm) of the center frequency over a temperature variation of -30[deg] Celsius to +50[deg] Celsius at normal supply voltage, and over a variation in the primary supply voltage of 85 percent to 115 percent of the rated supply voltage at a temperature of 20[deg] Celsius. (b) For battery operated equipment, the equipment tests shall be performed using a new battery without any further requirement to vary supply voltage. (c) It is acceptable for a transmitter to meet this frequency stability requirement over a narrower temperature range provided the transmitter ceases to function before it exceeds these frequency stability limits.