Gates FM-1B Technical Manual Download Page 38

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Summary of Contents for FM-1B

Page 1: ...i FM 1B 1KWFM TU NSMITTEB...

Page 2: ...written consent of Seller EXCEPT AS SET FORTH HEREIN AND EXCEPT AS TO TITLE THERE ARE NO WARRANTIES OR ANY AFFIRMATIONS OF FACT OR PROMISES BY SELLER WITH REFERENCE TO THE EQUIPMENT OR TO MERCHANTABI...

Page 3: ...INSTRUCTIONS FOR INSTALLING LND OPbRATING GATtiS FM 1B T ki lSMITTZR M55g7 I B a 0593 001 4 26 6l Gates Radio Company iuinGy Illinois...

Page 4: ...eference to grid voltage measurement at TF401 the test point on the driver panel Chis voltage will be 2P proximately lo 20 volts with voltages removed from the driver unit This is zccomplished by remo...

Page 5: ...85 50 185 75 187 25 to 191 50 191 75 193 25 to 197 50 197 75 199 25 to 203 50 203 75 205 25 to 209 50 209 75 211 25 to 215 50 2 15 75 The frequency range for commercial FM broadcasting is 92 1 MC to 1...

Page 6: ...association to say I told you so Remember it is difficult to radiate harmonics if the equipment is built to suppress the harmonics and it is 4 In many instances interference may be caused by overload...

Page 7: ...Installatioc 813 5904 001 Remote Control dring RiiC 20OA 813 5903 001 Remote Coz trol ring RX 1OC A 31735 1 iicrcmatch Cap Assy and iiCht matiCi A 31735 2 Micromatch Cap assy and Schematic B 65503 Sch...

Page 8: ...emphasis curve or flat L1 P db 50 to 15 e cps which ever is desired Distortion at 100 Modulation 1 or less 50 to 100 cycles 5 or less 100 to 10 000 cycles 1 or less 10 000 to 15 000 cycles Noise Fowcr...

Page 9: ...k panel space provided for the addition of the multiplex unit An important feature of this transmitter is the lack of frequency multiplication after the exciter This aids in helping to elim inate spur...

Page 10: ...s for K501 which is the line contactor Faith S518 in the local position the holding contacts on K501 are operative and the retiLote control unit is disconnected from the transmitter The function of S5...

Page 11: ...assist in the proper placement and orientation of the components that have been removed for shipment After the FPI 1B has been received and unpacked it should be carefully inspected for any mechanica...

Page 12: ...nted out that even a small amount of xirt unshielded is a very effective antenna at YH frequencies in transferring i2F to the grid xhere it is recti fied and oasszd on as noise or feedback It is prefe...

Page 13: ...factory and reads power being dalivered out of the transmitter to the transmission line l his meter h s been caiibrated and its calibrating Gn trols locked in place and should not be tampered without...

Page 14: ...maximum capacity It will also be noted that on this special bushing is a red dot which will appear directly o osite the black dot on the movable portion of the shaft This red dot on the special machin...

Page 15: ...n e the effGctivti electrical length of tha plate tank Increasing the s_ acing between the tuning and th plate tank lintis lc ngthcns the tiffectiva length of th plztz tank and lowers the frz uency da...

Page 16: ...VSWR To calibrate the VSWRportion of the unit turn the switch to calibrate position and adjust the meter to full scale deflec tion using the control with the knob Turn the switch to V R position and r...

Page 17: ...ng of the insulators When inspection of the air filter discloses that it is filled with dust or foreign matter they should be discarded and replaced with a new one The type of filter used in the FM 1B...

Page 18: ...ament 472 0307 OOO Transformer Powcr 614 0047 ooo 614 0092 000 614 0052 000 614 0046 000 614 0100 000 614 0093 000 614 0046 ooo 402 0015 000 Terminal Board Audio Terminal Board 115V h C and FM 1OA Jum...

Page 19: ...301 614 0113 000 Terminal Board TB302 614 009 000 Terminal V303 V302 374 0010 000 Tube 4 40011 XV3Ol XV302 404 0055 000 Socket 4 26 6X 2 FM lB hI5597 432 0026 000 520 0091 000 516 0204 ooo 520 0249 00...

Page 20: ...604 0032 000 Toggle Switch D 7 D T 406 0052 000 Pilot 0051 Light Green 406 000 Bsscmbly Pilot Light iisscmbly Red 406 0053 ooo Pilot Light ssembly rmber CCXT CTOiL P iNZL 386 0015 ooo Silicon Diode 10...

Page 21: ...01 TS232 614 0189 000 Tie Point XF Ol XF232 432 0 321 003 Fuseholder XV201 404 0316 000 Socket 600V SCREENRECTIFIER B0AB DASSY C833 thru C820 516 3382 000 Cap 01 uf 1 KV CR 31 thru CR820 384 3020 030...

Page 22: ..._ 800 0291 003...

Page 23: ...800 0292 003...

Page 24: ...DO 166...

Page 25: ...60 SO 40 E 30 30 20 20 O O be E 0 6 7 8 9 10 POW OuTFUr KW GRAPH PA EFFICIENCY FMlt 814 2123 001...

Page 26: ...I R5 4 20 h IOLd z 1 I KS05 CPMTE O L RELAY DECK 10 KW DRIVER FMlC 813 6026 001...

Page 27: ...1 I 24 FILTER INSTALLATION FMlC M 5597 813 5901 001...

Page 28: ...REMOTE CONTROL CONNECTIONS RDC 2OOA WlC FM 813 5904 001...

Page 29: ...M LB TB3 3 1 FtL ON TBJ 32 TBZ 3 ANT A MPS rs3 29 PLATE ON T 3 30 re 2 2 P R RRTE CuPes NT T Z F kPLhTE VOLTS I TBs I TBIOI iA 0 1 PLHTE OTBS 2 OFC REMOTE CONTROL CONNECTIONS RDC 1OC FMlC 813 5903 001...

Page 30: ......

Page 31: ...TSZOI 4 _ c TSii02 3 T6201 I 15202 Q L202 f5 DC PPOl CZGZ lOOK T B Y LJ m t D r...

Page 32: ...K4...

Page 33: ...INSTALLATION DETAILS COOLING AND EXTERNAL CONNECTIONS FMlC TRANSMITTER M5597 C 79128...

Page 34: ...TERMINAL BOARD WIRING FMIC DRIVER FOR F s h41...

Page 35: ...I J I I I I I I I I I I I I I 2 SCHEMATIC 50 WATT AblYLIt FOR BFE SOB BFE E...

Page 36: ...he desired level To tune the grid circuit place the negative probe of a volt meter into TP401 and ground the positive lead dith drive connected to input receptacle J401 tune C401 grid tuning for maxim...

Page 37: ...duce the possibility of oscillations and ox parasitics the input circuit of the following stage should be properly coupled and matched to the 51 ohm coaxial line connected to the 07xtput of the 50 wat...

Page 38: ...5 Grid voltage measured at LCP401 indicates voltage befpre applying screen and plaix voltage Plt Pwr Input 107 lliatts 97 Jatts 75 ilatts 72 Xatts 61 ratts Plt Dissipation 42 Watts 47 Watts 52 Watts 5...

Page 39: ...P401 P402 R4Ol R402 540 0482 OOQ R403 552 0058 000 R404 540 0367 000 R405 550 0073 000 Ii406 540 0748 000 R407 R400 540 0752 000 TB401 614 0096 000 TP401 614 0312 000 V401 V402 374 0051 000 XV4Ol XV40...

Page 40: ...8 I I I I I I I I I I 0 C 5 c 0 j SCHEMATIC 50 WATT AMPLIFIER hi5675 GATES RADIO COMPANY WNCY lLL NO S FOR BFE 508 BFE SOC ADIYISIOW OF HARRIS I TERT PE CDRPORA OW 826 5555 001...

Page 41: ...th the filter is one adaptor for reduction to a 7 8 coaxial line on one end A 7 a right angle bend is also provided to aid in a flexible installation INSTALLATION Since the fi1te r is not a standard s...

Page 42: ...3 L4 L5 LS L7 L3 L IO LII c 0 1 0 LOW FKEQ EQUIVALENT CIRCUIT 50 A INPUT fc I65 MC INSERTION LOSS 0 7s db OR LESS LENGTH FILTER WITH END FLANGES i II 1 AXlAL LOW PASS FILTER INFORMATION FILTER PLUS EN...

Page 43: ...I...

Page 44: ...as not corrected itself the trans mitter overload at fault will lock out and rcriain locked OL b until nanually reset If the transnitter experiences one 01 two overloo ds and then clears itself the ze...

Page 45: ...esistor R4 acts ns a surge resister while R2 is ncrely a bleeder resistor The two swit chcs cud cm push button which control the recycle unit me i OU Xltd on the 1 KW 5 vcr control panel The operation...

Page 46: ...le 574 0040 000 Relay 115 V AC DPDT 574 0105 000 Relay 6V AC 3PDT 576 0019 000 Tire Delay Relay 115V 10 Second 550 0071 000 542 0135 000 550 0059 000 3ico 0724 000 540 0752 000 552 0023 000 540 0468 0...

Page 47: ...il I I IR l t ll I OVERALL SCHEMA TIC FMIB DRIVER FOR FM 1OA 842 3115 001...

Page 48: ...INSTRUCTION BOOK FOR M5534 STEREOFM EXCITER I B 8888 0773 001 Gates Radio Company Quincy Illinois...

Page 49: ...is done to prevent low frequency transients and thumps from causing excessive deviation and loss of carrier from momentarily kicking the transmitter off the air These low frequency transients and thum...

Page 50: ...S The oven thermostat in HRlOl has been changed and the oven pilot light may seem to indicate erratic oven cycling This is normal for this type of thermostat however and is not an indication of a defe...

Page 51: ...2 Power Amplifier Stage V113 Page 1 2 2 3 4 5 20 5 10 Derivation of Frequency Modulated Pulses VlOl V104 Distortion Control Cl10 R119 Audio Amplifier V114 V115 Regulated Power Supply V116 V120 Crystal...

Page 52: ...ncv Fig 12 Fig 13 Fig 14 General Modulated Pulses from a Sawtooth waveform between pages Driving Pulse for Frequency Multiplier Stages Simple Pre emphasis circuit Simple De emphasis Circuit 6 7 8 11 1...

Page 53: ...exciter unit is shipped as an integral part of another unit this data will be included with the overall data sheet for the transmitter Maintenance 33 Troubleshooting 34 40 No Carrier 34 Low Carrier 34...

Page 54: ...S 6170 Standard 75 microsecond Pre emphasis Curve A 4165 Test Set up for FM B G5626 Typical Waveforms Existing in Stages VlOl thru V104 B 65625 Typical Waveforms Existing in States V105 thru VllO Tabl...

Page 55: ...Within 1 dB of standard 75 micro second pre emphasis curve or flat l dB 50 to 15 000 cycles depending on specifications of plug in audio pad Iistortion at 100 Modulation 1 or less 50 to 100 cycles 5 o...

Page 56: ...er stages The unit finds its greatest usage in driving 50 watt and 250 watt amplifier stages With some additional external metering the unit becomes a complete 10 watt FM transmitter Forced air coolin...

Page 57: ...for perhaps 20 seconds After this length of time the exciter power output will come up The only adjustments that will have to be made are to tune Cl59 output coupling and ClSS V113 plate tune for maxi...

Page 58: ...atts of power per hour Assuming that the crystal oven is ON continuously then the only thing that needs to be done in the normal days operation is to turn the main power ON when starting the broadcast...

Page 59: ...wing as it may be called is caused by applied audio The carrier therefore instantaneously swings back and forth the re quired amount at the audio frequency rate The amount of frequency swing is also r...

Page 60: ...cuit would be stiff in that when the 116 kc driving pulses shifted due to fre quency modulation prevent the circuit the flywheel effect of the plate circuit of Vl would from following faithfully and d...

Page 61: ...ed in the M5534 exciter unit Referring to drawing which is the overall schematic V105 has been substituted for Vl in Figure 1 and V106 has been substituted for v2 The intervening circuitry between V10...

Page 62: ...696 696 kc When the driving frequency of 348 kc instantaneously swings to 348 kc minus 348 cycles or 347 652 kc the tuned circuit in the plate side of V2 will double to two times 347 652 kc or 695 304...

Page 63: ...d by refer ence to functional block diagram C 77972 This drawing also shows the multiplication factor of each stage frequency range of each stage how many times crystal frequency has been multiplied a...

Page 64: ...ion coupling may also be varied considerably by Cl59 to match a wide variation of load impedances and termina tions as may occur when coupling the exciter unit into a succeeding amplifier stage An out...

Page 65: ...Fig 6 Fig 6 Typical Waveform Output V102 The pulse of Fig 6 is applied to the first section of V103 V103 is essentially a sawtooth oscillation stage that fires only when a driving pulse is applied Th...

Page 66: ...e the waveform will appear as in Figure 8 if bias has been properly set Dotted lines show the waveform as it w ould appear if VlO4 were not in the circuit Figure 8 Typical Waveform Output of V103 V104...

Page 67: ...arts to fall off the saw tooth waveform has to rise to a succeedingly less and less value for the tube to conduct This means that the pulses in the plate circuit will be occurring sooner than if no mo...

Page 68: ......

Page 69: ...modulating voltage applied to the modulator stage V104 be faithfully translated into alternate rari fications and compressions of the pulse repetition rate To accom plish this purpose several conditio...

Page 70: ...ollower V115 type 6AQ5 tube V114 and V115 work together as a unit since they operate within a feed back loop The negative feedback is provided by condenser Cl63 and R158 I 159 in series Varying the va...

Page 71: ...d by a series type regu lator tube V117 a type 6080 tube VllS is a control tube that amplifies minor voltage variations of the regulated output V119 and V120 are reference tubes Proper voltage of 320...

Page 72: ...e and raise the voltage supplied to the exciter proper Conversely the arm moves in the opposite direction if voltage at the plate of Vl18 falls Approximately the same results are accomplished should t...

Page 73: ...filament will cause FlOl to blow FlOl is 1 5 A Slo Blo variety When the exciter is transmitting a full 10 watts output power current drawn from the 117 VAC line will be about 1 ampere However when th...

Page 74: ...S 6170 showing relationship between the audio input and modulated output Frequency of the audio spectrum is plotted horizontally and the output of the unit for an input that is con stant in respect to...

Page 75: ...emphasis at the receiver must be the reverse of the pre emphasis characteristic This is accomplished by making the time constant of the resistor and capacitor in Fig 14 equal to that of the pre empha...

Page 76: ...at this point is usually 600 ohms A 31143 is a schematic diagram of two types of plug in units Diagram A is that of a flat pad with an insertion loss of approxi mately 17 5 dB at any audio frequency D...

Page 77: ...the transmitter which raised the higher frequencies 15 000 cycles 17 dB above 400 cycles when the receiver was incapable of passing anything above 3 000 cycles Conversely if the audio response of the...

Page 78: ...urns open turns or a change in value of some other component connected across the coil The value of any other parts connected across the coils is to be considered insignificant when compared to the DC...

Page 79: ...uld not exceed a drain of about 30 ma for continuous operation Reducing screen voltage of V113 by adjustment of R155 will drop V113 current drain from about GO ma 25 ma for 2 watt output for 10 watt o...

Page 80: ...X 250 06 X 320 15 06 X 305 18 5 watts Assuming an output power of 10 watts Plate dissipation V113 Power input Power output 18 3 10 8 3 watts Efficiency of VllS Stage Power Output Power Input 10 18 3...

Page 81: ...9 to 13 34 to 39 65 to 75 1 5 to 2 5 54 to 58 72 to 76 65 to 80 122 to 132 0 DC 4 to 6 V RMS RF 0 DC 4 to 6 V RMS RF 110 to 120 120 to 140 190 to 210 5 to 10 150 to 170 13 to 17 320 NO DRIVE VOLTS 1...

Page 82: ...ossible to obtain enough power to drive the monitor from the antenna without introducing another amplifier ahead of the monitor to raise the received signal up to the necessary level In higher powered...

Page 83: ...cause the carrier frequency to vary approximately 30 000 cycles Changing the value of Cl03 from 150 minf to 50 mmf will raise carrier frequency about 10 000 cycles Changing Cl03 from 150 mmf to 250 m...

Page 84: ...rs at the lowest modulating frequency in other words if distortion is 5 at 50 cycles then distortion can be expected to be better at all higher modulating frequencies Occasionally a higher distortion...

Page 85: ...per amount modulation level would be 35 In this case the proper Keeping the input audio level con stant the frequency may then be adjusted upward to 15 000 cycles and then downward to 50 cycles Using...

Page 86: ...ing the value of Cl60 from 50 to 200 mmf will raise the audio response as measured at TP118 about 3 dB at 15 000 cycles Audio response as observed at TP118 will usually have to be com pensated high ab...

Page 87: ...red A point often overlooked in making MI noise measurements is the sampling For example loop or device if the RF sampling loop is mounted in a P A chamber where blower vibration is apt to occur this...

Page 88: ...ory test data sheet When the exciter unit is first received and placed into operation it is advisable to go over these test point voltages and record the reading obtained weekly or monthly The test po...

Page 89: ...edies and troubleshooting hints suggested A No Carrier Of the many problems that can occur this perhaps is the most serious and yet the easiest defect to find tube has usually gone completely dead Whe...

Page 90: ...rier The same general routine used to track down the stage causing a carrier failure can be used to check for a low carrier Tracing down the fault for a low carrier can be more elusive though be cause...

Page 91: ...on will be damped and only occurs momentarily but may be aggravating E Carrier Off Frequency When the carrier is consistently too far removed from proper center frequency the trouble can be traced dir...

Page 92: ...trouble It is characteristic of an FN system that the greatest difficulty in attempting to modulate occurs at low frequencies When the overall distortion is high between 50 and 400 cycles only the tr...

Page 93: ...L103 are most apt to cause this difficulty Improper tuning of the modulation and frequency monitor can also affect apparent frequency response A change in the components associated with modulator stag...

Page 94: ...he following RF voltage measurements were made using an II P Model 41UU VTVM The AC probe RF was utilized in all cases Also the probe was utilized in all cases Also the probe was placed into the circu...

Page 95: ...Location Readings Pin 1 6 2 Vlll 23 V Pin 5 V112 9 v Pin G VllZ 9 5 v Pin 1 2 V112 26 V Pin 1 4 3 V113 19 v Pin 6 4 8 V113 150 v 5 26 68 4o MS534...

Page 96: ...6 0043 000 c152 c159 520 0112 000 C154 C158 520 0169 000 2 g 02 Lamp G 8 V 47 Std 75 microsecond pre emphasis pad Cap 1 mfd 400 W V DC Cap Vari 4 5 to 100 mmfd shaft type Cap 00015 mfd lO 600 N V cera...

Page 97: ...R124 R104 R109 R112 K139 R158 11159 R164 11175 540 0202 000 Cap Trimmer SO 380 uuf Cap p Filter 30 30 mfd 525 IV V DC Cap Filter 16 mfd 450 W V Cap 500 mmfd 20 500 V DC ceramic button type Cap 500 mm...

Page 98: ...50 0067 000 913 2346 001 SlOl 604 0005 000 TlOl 472 0088 000 T102 478 0144 000 T103 472 0248 000 TBlOl 614 0054 000 Description lies Res Res Res Res 10k ohm s w 10 270k ohm h W 10 68k ohm 2 lV 10 1500...

Page 99: ...06 0057 000 XATl XC165 XClG6 XV116 XV117 404 0068 000 XFlOl XF102 XHKlOl 402 0021 000 Fuseholder 404 0053 000 Crystal Oven Socket XVlO6 XVlO7 XV108 XVlO9 xv11o xv111 xV112 xv115 xv118 xv119 xv120 XV10...

Page 100: ...7 U U U __ r _ _ _ JL 8_ n n n n_ FM EXCITER M5534 GENERAL LAYOUT El3 1359 001...

Page 101: ......

Page 102: ...L r...

Page 103: ...B PEE E lPHAS S P4D I5986 SCHEMATIC FOR PLUG IN PADS USED IN GATES FM TRANSMITTERS I 45597 813 1143 001...

Page 104: ...15 14 13 12 i 11 STANDARD PRE EMPHASIS CURVE TINE CONSTANT 15 bUCROSECONDS Solid Line Frequency Response Limits Shown by use of Solid and Dashed Lines Cycles Per Second FIGURE 12...

Page 105: ...I...

Page 106: ...I NOTE THE ABOVE PP WAVEFORM MEASUREMENTS WERE MADE WITH A MODEL 524 AD TEXTRONIX SCOPE AN UNCALIBRATED SCOPE MAY BE CALIBRATED BY USING FILAMENT VOLTAGE TO SET A REFERENCE PEAK TO PEAK VOLTAGE EQUAL...

Page 107: ...c P 0...

Page 108: ...A DIVISION OF HARRIS INTERTYPE...

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