Product Support Bulletin 847

LAND MOBILE PRODUCT SECTOR 1301 E. ALGONQUIN RD. SCHAUMBURG, IL. 60196 (847) 576-0180 PSB # 847 APC # 448,509,225,360,590,675,537,301,482,409,218,676 DATE: SEPTEMBER ,1998 EXPIRES: 9/30/99 SUBJECT: QUANTAR/QUANTRO STATIONS DRIFTING OFF FREQUENCY MODELS AFFECTED : All T5365A QUANTAR/QUANTRO STATIONS THAT INCLUDE THE UHSO (ULTRA HIGH STABILITY OSCILLATOR) OPTION X873 SYSTEMS AFFECTED : CONVENTIONAL AND TRUNKING ISSUE: The Receiver and Transmitter will drift off frequency by approximately 30Khz. Station alarms may or may not be generated to let the user know of the fault. CAUSE: Marginal power out of the ovenized oscillators will cause a miscount of the 5Mhz pulses. The result will be that the 5Mhz reference frequency will be counted as a lower frequency and the Pendulum IC will fail to lock on to the reference frequency. RESOLUTION: On the TTN5070C module change the value of R609 from 10K ohms to 2.7K ohms P/N 06-11079A84 and change the value of R611 from 56 ohms to 39 ohms P/N 06-11079A40 (Diagram 1).   NOTE: The above referenced resistors can be obtained at no charge from the Americas Parts Department by calling 1-800-422-4210 and making reference to this bulletin.   Authorized Motorola Service Shops will be allowed 1 hour per station to change the resistors and check out station operation by making reference to this bulletin and entering the standard labor claim form RO21-19.   Front of Board R609 E400 Q601 Q602 R611 R615 C610 C611 J101 Y600     DIAGRAM 1