Section I. 1. Scope of Manual This manual contains the necessary instruc- tions for the installation, operation, mainten- ance, and repair of Radio Receiver R-257/U (fig. 1). Theory is also included so that the repairman will have a better understanding of the radio receiver. 2. Forms and Records The following forms will be used for reporting unsatisfactory conditions of Army equipment and when performing preventive maintenance: a. DD Form 6, Report of Damaged or Im- Section Il. 3. Purpose and Use Radio Receiver R-257/U is a 21-tube double conversion superheterodyne receiver. It oper- ates in the frequency range of 25 to 50 mc (megacycles) ata crystal-controlled preset fre- quency. The receiver itself does not have any operating controls. These controls are fur- nished in radio sets in which the receiver is used. a.
DesignationTM 11-5071
EditionDec 1954
StatusSuperseded
Pages124
FunctionComms Signal
CollectionHistoric
Public domain (U.S. Government work)