AN-GRC-19_Serviceability_standards_SB11-100-147_1955.pdf

SB 11-100-147 DEPARTMENTOFTHEARMYSUPPLYBULLETIN SERVICEABILITY STANDARDSFOR RADIO SET AN/GRC-19 1. General.a.See SB 11-100,Serviceability StftndardsforSignalEquipmentinHandsof Troops,for generalprovisionsof serviceability standaldl1, andexplnationsof theuse of this series of flJpply bulletins.An indexto supply bulletinso. filJrviceabilitystandardsfor specific equipmentsItalso included for reference purposes. b.Commentsandconstructivecriticismof thesebulletinsshouldbesubmittedtothe ChiefSignalOfficer(SIGTM-M),Washington 25,D.C. 2. Description of the Equipment.RadioSeL AN/GRC-19is a receiverand transmittercom- binationdesigned for receptionand transmission of radiotelegraphand voice signals.The oper- fiting frequ13ncy rangeof thetransmitteris 1.5 to20megacycles.Theoperatingfrequency rall;:e of the receiver is 0.5 to 32 megacycles. 3. GeneralRequirements.a.Theprimary po or source must supply 22 to 30 volts dc (direct current)at 45 amperes.(Surge currentsup to 160 ampereswill be encountered.)Thevehicle in which the set is installed will adequatelyfurnish the requiredpower. b.The I5-footwhip antennasupplied with the radio set, or AntennaGroup ANjGRA-I2issued separately,may be used to conductthe tests in this standard. c. RadioSetAN/GRC-19will be testedby establishinga line of sight communicationnet over open terrain,betweenthe radio sets.A monitor set,knowntobe in goodoperatingcondition, shouldbe locatedat a reasonn,ble distancefrom the other sets to provide both voice and cw trens- missions and receptionfor checking the radio sets undertest.Themonitorset shouldprovidea test transmissionon one frequencyin each band in the transmitter. d.The accessories suppliedwiththe mdioset will be connected as follows: (1) The telegraphkey to an audio connector atthe receiverto kqthetransmitter. (2) The headsetto the audioconnectoron the receiver. (3) The microphoneto the audioconnector on the transmitter. 4. Special Requirements.a.All cablesmus beundamagedandsecurelyattachedtotheir proper receptacles. b.The fuses in use, and the spares, should be of thc indicatedvalue and located as follows: (1) Mountedon the transmitterfrontpanel is one 15 ampere fuse. (2) :Mounted inside the transmittercase are- Ca)One 15 ampere spare fuse. (b)One 20 amperefuse in use, n,nd one spare. (c)One 30 amperefuseIIIuse, andone spare. (3) Mountedon the receiver front panel are- (a)One5 amperefuseinuse, andone spare. (b)One 0.5 amperefuse in use, andone spare. c.Controlsshouldbechecked for positive action.There must not be binding, scraping, misalinement, or excessive looseness. 5. Preliminary Procedure.a.Set the controls on the receiver as follows: ControlS.Uing B. F. O.switch.OFF AGC switchON FUNCTIONswitchOFF BANDWIDTHswitch8kc DIAL DIMswitchOFF b.Set the controls on the transmitteras fol- lows: Control DIAL DIMswitch._ TEST KEY_ RELA Y-NORMAL-DUPLEX_ SERVICESELECTOR_ LINELEVEL_ SeUing OFF OFF NORMAL OFF +12 DBM 6. Test Procedure and Requirements.a.Pro- ceed as follows and note particularlythatthe operation of the radio set is consistent with the specified requirements. (1) Start the receiver by placing the FUNC- TION switchin the STAND BY position. Startthetransmitterby placing the SERVICESELECTORswitch in the STAND BY position.Allowthe equip- ment to warm up for 5 minutes before operating. (2) Setthereceiverfunctionswitchto NORMAL.Set the DIAL DIM con- trol to DIAL DIMand then to ON. The dial lamp willlight and its brilliance will increase with each position. (3) Adjustthe A. F. GAIN and the R. F. GAIN-SQUELCH control for noise out- put from the headset. (4) Calibrate the receiver in accordance with the instructions contained in paragraph 30inTM 11-274. (5) Set the transmitterSERVICE SELEC- TORswitch to CALIBRATE.After approximately 1 minute, a movement of air will be felt at the air vents indicating that the blower is in operation. (6) SetthetransmitterTESTMETER switchtotheBATTposition.The TESTMETERwill indicatenormal batteryvoltage in the shaded portion marked BATT. (7) Set the transmittr DIAL DIM control to DIM,and then to FULL.The dial lamp will light and increase in brillianM when the control is moved from DIM to FULL position. (8) Calibrate the transmitter in accordance with the instructions contained in para- graph31of TM11-274. b.When operation is on voice, proceed as fol- lows: (1) Set the SERVICE SELECTOR switch to VOICE and the TEST METERto PA GRID. (2) Select a frequency for each of the ten bands on the transmitter.Preset the transmitter to eight of these frequencies, one for each position of the PRESET CHANNELS switch. (3) The auto tune circuit will function for each position of the switch.On com- pletion of each autotunecycle, the TESTMETERwill indicateinthe shaded portion marked PA GRID. (4) Set the TEST METERto PA CATH and press the microphone button to key the transmitter.The TUNING INDI- CATOR lamp will light, the dynamotor will start, and the TEST METER will read in the shaded portion marked PA CATH. (5) Speak clearly into the microphone and establishcontactwiththemonitor. Transmission and reception should be clear and intelligible. (6) During transmission with the monitor, the operation of the transmitter should be consistent with the followin,: (a)The AUDIO LEVELmetershould read at least 85 percent. (b)Voice sidetone should be heard in the headset. (7) During reception from the monitor, the receiver operation should be consistent with the following: (a)VarytheGAINcontrolclockwise through its entire range.The signal in the headset will increase in volume as the control is turned. (b)Vary the ANTENNA TRIMcontrol through its entire range.The volume of the signal in the headset will vary. Set the ANTENNATRIMcontrol for MAXIMUM signal output. (c)Set the BAND WIDTH switch succes- sively to each position.As the band width is decreased, the volume of the background noise in the headset will be reduced. (d)SettheFUNCTIONswitchto LIMITER.The volume of noise in the headset will be reduced. (e)Set the FUNCTIONswitch to SQ. Increase the RFGAIN SQUELCH THRESH until the noise in the head- set is reduced to zero.When a signal is received from the monitor, it will be heard in the headset, indicating proper squelch operation. c.When operation is on cw, proceed as follows: (1) Set the SERVICE SELECTOR switch to CW and the TEST METER to PA CATH. (2) Set the receiver B. F. O. switch to ON. ByORDEROF THE SECRETARY OF THE ARMY: OFFICIAL: JOHN A. KLEIN, Major Geneml, United States A1my, The AdjutantGeneral. (3) Set the TEST KEY switch to ON.The dynamotor willstart after approximately 10 seconds, the indicator lamp will light, and the TEST METER will indicate in the shaded portion marked PA CATH. (4) Release the TEST KEY and key the transmitter with the telegraph key.The transmissionandreception, withthe monitor station, must be clear and intel- ligible and a 400 cycle side tone will be heard in the headset. (5) During reception, vary the BFO PITCH control through its entire range.The tone of the cw signal will vary as the control is varied. d.Repeat the tests in bandcabove, using the remaining seven frequencies. e.Set up the transmitter for the other two fre- quenciesand repeat the tests inbthroughdabove. MAXWELL D. TAYLOR, General, United States Army, Ohief of Staff. DISTRIBUTION: Active Army: CNGB (1)Trans Terminal Comd (2) Tee Svc, DA(1) except C:ilGOOS Sup Agencies (2) (50)Sig Fld Maint Shops (3) Tee Svc Bd (1)Sig Lab (5) Hq CONARC (4)Mil Dist (1) CONARC Bd (Incl ea test sec) (1)Unitsorganizedunderfollowing Army AA Comd (2)TOEs: OS Maj Comd (5)5-I5R,Engr Cmbt Bn, Div (2) OS Base Comd (5)5-I6R,Hq,H units-sameas Active Army except allowance is one copy to each unit. USAR:None. For explanation of abbreviations used, see SR 320-50-1. TAGO 3743A 11-57R, Armd Sig Co (3) ll-I28R,Sig Depot Co (3) 11-500R (AA-AE), Sig Svc Org (3) 11-557R, Abn Sig Co (3) 11-587R, Sig Base Maint Co (3) 11-592R, HqHq Co, Comm Recon Bn (2) 32-57R,Comm Recon Opr Co (2) 32-500R, Comm Recon Org (2) 44-I25R,AAA Bn, AW, 5mbl (2) 44-126R, Hq&Hq Btry, AAA Bn, AW, 5mbl (2) 44-276R, Hq&Hq Btry,Abn AAA Bn, AW (2) 44-277R, Abn AAA Btry,AW (2)