SERVICE AND REPAIR NOTES

Bulletin

TECHNICAL INFORMATION / 8000 W. SUNRISE BLVD. / FT. LAUDERDALE, FL 33322

This SRN Supersedes SRN1290

SRN-1290A
APC 672, 749
October 1999
Deadline: 12-31-00

Memo To: SRN Mailing List

From: Radio Product Group / CGISS

Subject: HT750/HT1250 VHF (136 �174MHz) Range Limitation

Symptoms:

1. Radio will not receive or carrier is noisy when receiving a radiated signal in a location that is within the usual coverage area.

2. Radio transmitted signal will not always cover proper range or is noisy when operating within the usual coverage area.

Please note that this is radiated receiver sensitivity and radiated transmitter power effect. It cannot be tested using the conducted receiver sensitivity or conducted transmitter power measurement procedure.

Potential Problem Radios:

Models Affected: AAH25KDC9AA2AN, AAH25KDC9AA3AN, AAH25KDG9AA4AN,

AAH25KDF9AA5AN, AAH25KDH9AA6AN

Serial Numbers: 672TYWxxxx through 672TZRxxxx

749TYWxxxx through 749TZRxxxx

Cause:

The radio is exhibiting excessive processor noise. The antenna matching circuit needed to be optimized.

Corrective Action:

Two radio design improvements have occurred.

1. Improve the radio code to decrease processor noise.

2. Improve the antenna matching circuit to provide a better power transfer from the antenna to the harmonic filter.

HT750/HT1250 VHF radios with the serial numbers above may exhibit poor range symptoms. This depends on the range of operation.

HT750/HT1250 radios that exhibit poor range must be sent to the Radio Support Center for repair. Their address appears below.

Motorola Inc.

Radio Support Center

3761 South Central Avenue

Rockford, IL 61102

Radios returned from the Radio Support Center will have an information label on the back indicating the rework was done. Refer to the firmware version. It should read R02.00.01R. Radios shipped after the above serial number date will have a label that reads firmware version R02.00.01. Even though the "R" is not present the radios have the modifications.

Note: If returning twenty five or more portables to the Radio Support Center for the modification please phone 888-227-6772 and ask for Jim Dahring, ext. 1314. If Jim is not available ask for Paul Sahy ext.1315. This will allow the Radio Support Center to scheduled the modification and return the radios promptly.

When returning the portable, please reference this SRN

Warranty is authorized for the sending facility at $25.00 each.

Warranty is authorized for the Radio Support Center at $40.00 each.


If applicable, enter this information or note this bulletin number and subject material in the appropriate equipment instruction manuals and make necessary schematic diagram changes. Enter this bulletin in the correct MASTER and CLASSIFIED INDICES for future reference.

Labor or parts warranty reference is limited to products sold and in use in the United States, for products sold or in use internationally this bulletin is for informational purposes only. Radios that are Agency Approved must follow designated agency guidelines.

SRN-ISO