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Harris STM-1, Technical Manual, Page: 87 / 123

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Summary of Contents for STM-1

Page 1: ...spectrum analyzer A front panel switch permits conve nient meter display of upper sideband USB and lower sideba nd LSB alignment signals PEAK READING METERS The STM 1 incorporates three 3 meters two o...

Page 2: ...PONSE 0 5 dB 400 Hz to 15 kHz LAND R SEPARATION 35 dB 400 Hz to 5000 Hz 30 dB 5000 Hz to 12 500 Hz LAND R THO 0 5 70 modulation 50 Hz to 15 kHz LAND R S N 60 dB reference 70 modulation 400 Hz PILOT FR...

Page 3: ...eamPoweredRadio Com r T M No 888 2172 001 TECHNICAL MANUAL STM 1 AM STEREO MONITOR 994 8731 003 HARRIS CORPORATION Broadcast Division Copyright HARRIS CORPORATION 1983 All Rights Reserved Printed July...

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Page 5: ...use of improperly trained or inexperienced personnel performing such tasks During installation and operation of this equipment local building codes and fire protection standards must be observed The f...

Page 6: ...IFICIAL BREATHING TILT HEAD PINCH NOSTRILS MAKE AIRTIGHT SEAL 4 QUICK FULL BREATHS REMEMBER MOU TH TO MOUTH RESUSCITATION MUST BE COMMENCED AS SOON AS POSSIBLE CIRCULATION DEPRESS STERNUM 11 2 TO 2 ri...

Page 7: ...s possible e If arms or legs are affected keep them elevated NOTE If medical help will not be available within an hour and the victim is conscious and not vomiting give him a weak solution of salt and...

Page 8: ...Operation of Mod Monitor Transmitter Test Exciter IF Test Independent Sideband Mode SECTION IV PRINCIPLES OF OPERATION Introduction General Block Diagram Description Input and AGC Section Synchronous...

Page 9: ...Switches Printed Circuit Boards SECTION VI TROUBLESHOOTING Introduction Technical Assistance General Unit Will Not Lock Pilot Light DC AC Parameters Waveforms SECTION VII PARTS LIST Introduction Repl...

Page 10: ...Indicators 3 3 STM 1 Interior View as Viewed From Rear Controls and Indicators 3 4 STM 1 Rear Panel Controls and Indicators 3 5 STM 1 VCO Board With Cover Removed Controls and Indicators 3 6 Test Set...

Page 11: ...to setup and operate the STM 1 AM STEREO MONITOR d SECTION IV PRINCIPLES OF OPERATION provides detailed theory of operation of the STM 1 AM STEREO MONITOR e SECTION V MAINTENANCE provides guidelines f...

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Page 13: ...nces and reasons for return are to be included in the request for return Custom equipment or special order equipment is not returnable In those instances where return or exchange of equipment is at th...

Page 14: ...INJ permits determination of the pilot injection level on a remote indicator 2 13 FRONT PANEL SWITCHES 2 14 There are five front panel switches and under normal operation these switches are in the fol...

Page 15: ...odulation output for measurement These outputs can be used to deter mine distortion response or other audio performance parameters When the selector switch is in the ISB mode these outputs indicate th...

Page 16: ...tereo signals The modul ation is given in percentage and in dB 2 21 FRONT PANEL ADJUSTMENT 2 22 There is only one front panel adjustment and that is the RF LEVEL control which allows setting of the RF...

Page 17: ...ndicators on the HARRIS STM 1 AM STEREO MONITOR as well as operating procedures to follow in using the HARRIS STM 1 AM STEREO MONITOR 3 3 CONTROLS AND INDICA fORS 3 4 Refer to figure 3 1 through 3 5 f...

Page 18: ...PILOT PRESENT LED AM STEREO OR ISB RECEPTION MODE SWITCH 3 2 MULTIMETER FUNCTION SWITCH Q CHANNEL OUTPUT STEREO HEADPHONES OUTPUT 2172 1 Figure 3 1 STM 1 Front View Controls and Indicators 888 2172 00...

Page 19: ...WITCH SYNTHESIZER S301 CRYSTAL PILOT CAL CIRCUITRY DOWN CONVERTING MIXER LVPS DC FUSES 2172 2 Figure 3 2 STM 1 Interior View As Viewed From Front Controls and Indicators 888 2172 001 WARNING Oiooonneo...

Page 20: ...vco vco PROGRAMMING SI POWER TRANSFORMER DOWN CONVERTER AND DECODER PROGRAMMING FOR SYNTHESIZER S301 S302 3 4 SYNTHESIZER Figure 3 3 STM 1 Interior View As Viewed From Rear Controls and Indicators 888...

Page 21: ...R RF FROM TRANSMITTER INPUT I r F1 nrPLACt f7 4 2 L 1 1 e o usr 0 IF INPUT FROM EXCITER FOR TEST 0 tl 0 c LEFT OUTPUT REMOTE OUTPUTS w 1 4 5 3 RIGHT OUTPUT 9 Figure 3 4 STM 1 Rear Panel Controls and I...

Page 22: ...OGRAMMABLE CENTER FREQUENCY Sl FOR VCO 15 VOLT DC INPUT RF OUTPUT VCO PRINTED CIRCUIT BOARD 2172 5 Figure 3 5 STM 1 VCO Board With Cover Removed Controls and Indicators 3 6 888 2172 001 WARNING Discon...

Page 23: ...the multimeter switch to the PILOT INJ position and read the pilot injection level The pilot should be between 6 1 2 and 8 1 2 injec tion and should be set to 7 5 If adequate pilot is present the pil...

Page 24: ...erconnect the two IF signal ports the proper switch thrown in the rear of the moni tor and the monitor is operating on the IF of the exciter Similar to the RF signal the IF signal is AGCed and likewis...

Page 25: ...en modulating with a lower side band frequencies below 256 kHz one should try for minimum upper sideband I I I X J s J G 0 G 0 fTI z 0 0 fTI 0 I I F SIGNAL I F I N GEN STX I AUD IO RF AM XMTR SAMPLE R...

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Page 27: ...g the IF signal in the STX 1 exciter Referring to the block diagram in Section VIII there are several major operating areas in the modulation monitor First the RF signal is down converted to IF at 256...

Page 28: ...following paragraphs 4 13 INPUT AND AGC SECTION 4 14 The RF input from the transmitter 1 s coupled to a potentiometer to permit operation over a wide range of RF levels A sample of the RF signal is c...

Page 29: ...Hz the PLL output DC l evel varies and the gain of the voltage controlled amplifier varies The signal passing through the voltage con trolled amplifier is the L R G information A signal pilot at 55 Hz...

Page 30: ...tor Thus the incoming signal is locked to the VCXO which in turn locks the VCO This synthesizer has two phased locked loops 4 30 POWER SUPPLY 4 31 Power for the modulation monitor is provided from DC...

Page 31: ...YNTHESIZER U302 8 POSITION SWITCH S301 vcxo Y301 16 U303 IOI II U301 MODULUS CONTROL RF FROM XMTR 4 U7 U305 vco LOCK 4 U9 4 U6 LO RF j ZI IF 56KHZ if I F FROM EXCI TER II Iti 11011 90 vcxo LOCK TO P I...

Page 32: ...ndent resistor is placed in shunt with the RF signal to perform the necessary AGC action As the RF signal increases the light dependent resistance decreases as determined by the AGC loop thus holding...

Page 33: ...AGC action required to hold the IF output at a constant signal level 4 48 The output of the Q channel is amplified by UlO and is a part of the automatic frequency control The Q channel output is the f...

Page 34: ...and is buffered and filtered by amplifiers in UlO The output of the I channel is the l L R information and supplies the signal for the AGC volt age The output of the I channel has a DC component and...

Page 35: ...e VCXO provides the stable reference for the RF down converter PLL 4 60 Following the block diagram in figure 4 1 the RF in the transmitter is down donverted in the mixer Zl to a 256 kHz IF The local...

Page 36: ...7 1 2 VDC A negative supply voltage is also provided for by U403 at 7 1 2 VDC To further regulate and protect the raw 19 supplies are also coupled through fuses F403 and F402 to the other part of the...

Page 37: ...ned with the inertia of the meter creates a slowly time varying signal This causes the needle to wander back and forth at the difference frequency To adjust the exciter Pilot signal to 55 Hz precisely...

Page 38: ...OGBOOK 5 6 The maintenance logbook should contain a complete description of all maintenance activities required to keep the equipment in operational status A listing of maintenance information to be r...

Page 39: ...tion or the existence of some defect can be detected and corrected before serious trouble occurs Become familiar with operating tempera __ tures in order to recognize deviations from the normal range...

Page 40: ...ccumulations of dirt or dust could form leakage paths b Use compressed dry air to remove dust from the area WARNING I ALWAYS WEAR SAFETY GOGGLES WHEN USING COMPRESSED AIR 5 13 CAPACITORS Preventive ma...

Page 41: ...l knob setscrews do not disturb knob alignment b If necessary clean component with a dry brush or a lint free c lath c When dirt is difficult to remove clean component with a lint free c l oth moisten...

Page 42: ...uts and condi tion of rubber grommets b Remove indicator switch by pulling the plastic cover indicator assembly from the case and rotating the assembly 90 degrees c Inspect indicator assemblies for br...

Page 43: ...www SteamPoweredRadio Com e Use standard practices to repair poor solder connections with a low wattage soldering iron 5 6 888 2172 001 WARNING Disconnect primary power prior to servicing...

Page 44: ...e AM stereo mod monitor is an accurate piece of test equipment not to be recalibrated in the field It is suggested that recalibration of this unit not be attempted in the field by station personnel Ho...

Page 45: ...far enough off that it is impossible for the monitor to lock on to the incoming carrier It may be that the crystal in the monitor has also drifted in such a manner as to make lock impossible or a com...

Page 46: ...lO Pin 6 0 97 VDC 2 AGC to LDR Ul Pin 7 10 6 VDC 3 Q Channel UlO Pin 14 0 0 VDC 4 VCXO AFC Ul3 Uin 1 1 5 VDC 5 VCXO AFC L304 8 5 VDC 6 VCO AFC E6 3 9 to 11 VDC 7 Pilot Detector Ul8 Pin 12 2 3 VDC 8 Lo...

Page 47: ...LOWER TRACE U3 Pin 13 Q TITLE I and Q at Detector MODULATION 1 kHz 50 Single Chan VERTICAL SCALE 1 v division HORIZONTAL SCALE 1 us division UPPER TRACE U3 Pin 4 I LOWER TRACE U3 Pin 13 Q TITLE I and...

Page 48: ...ACE 013 Pin 7 I LOWER TRACE Ull Pin 8 Q COMMENT Pilot OFF TITLE I and Q Before Filter MODULATION 1 kHz 50 Single Chan VERTICAL SCALE 0 5 v division HORIZONTAL SCALE l us division UPPER TRACE Rl09 R91...

Page 49: ...Pin 8 Q COMMENT Pilot ON TITLE I and Q Before Filtering li IJ il I _ I if MODULATION 1 kHz 50 Single Chan VERTICAL SCALE 1 v division HORIZONTAL SCALE 1 ms division OPPER TRACE Ul9 Pin 1 R LOWER TRAC...

Page 50: ...I LOWER TRACE Ul3 Pin 13 Q TITLE I and Q at Detector MODULATION 1 kHz L R 100 VERTICAL SCALE 0 5 v division HORIZONTAL SCALE 1 ms division UPPER TRACE U2 Pin 6 TITLE IF Signal Mono MODULATION 1 kHz L...

Page 51: ...AL SCALE 2 v division HORIZONTAL SCALE 1 ms division UPPER TRACE Ul3 Pin 7 I LOWER TRACE Ull Pin 8 Q COMMENT Pilot OFF TITLE I and Q Before Filtering Figure 6 1 Waveforms Sheet 5 of S 888 2172 001 WAR...

Page 52: ...available 24 hours a day seven days a week from the HARRIS Service Parts Department Telephone 217 222 8200 to contact the service parts department or address correspondence to Service Parts Departmen...

Page 53: ...INDEX UNIT NOMENCLATURE STM 1 AM STEREO MOD MON BASIC AM STEREO MOD MON CABLE MOD MONITOR PC BD AM MOD MONITOR PC BD VCO PART NO 994 8731 003 994 8731 004 929 9356 001 992 6160 004 992 6159 001 7 2 88...

Page 54: ...403 001 943 4148 001 943 4149 001 992 6160 004 992 6268 001 DESCRIPTION CAP lUF 50V DISC LED RED LED YELLOW FILTER RFI POWER LINE FUSE FAST CART 2A 250V RECEPTACLE BNC UG 1094 U JACK PHONE MOLDED 3 C...

Page 55: ...CR407 CR408 cool C002 C003 C004 C005 C006 C007 C008 C009 co10 co11 co12 C013 C014 C015 C016 C017 C018 C019 C020 7 4 HARRIS PART NO 384 0205 000 386 0093 000 528 0030 000 384 0205 000 528 0030 000 384...

Page 56: ...500 0913 000 CAP 1200PF 500V 5 1 0 C059 500 0833 000 CAP MICA 390PF 500V 5 1 0 C061 500 1201 000 CAP 2400PF 500V 5 1 0 C062 506 0243 000 CAP 15UF 63V 5 1 0 C063 500 0913 000 CAP 1200PF 500V 5 1 0 C06...

Page 57: ...lKV 20 1 0 C308 500 0903 000 CAP 2700PF 500V 5 1 0 C309 506 0232 000 CAP OlUF 63V 5 1 0 C310 C311 516 0453 000 CAP lUF 100V 20 2 0 C312 506 0232 000 CAP OlUF 63V 5 1 0 C313 500 0903 000 CAP 2700PF 50...

Page 58: ...ES 25W 12K OHM 5 1 0 R006 R007 540 0958 000 RES 25W 82K OHM 5 2 0 R009 540 0936 000 RES 25W lOK OHM 5 1 0 ROlO 540 0953 000 RES 25W 51K OHM 5 1 0 R012 540 0947 000 RES 25W 30K OHM 5 1 0 R013 540 0933...

Page 59: ...1 0 R070 540 0938 000 RES 25W 12K OHM 5 1 0 R071 548 1361 000 RES lOK OHM l 4W 1 1 0 R072 548 1440 000 RES 25 5K OHM l 4W 1 1 0 R073 548 1361 000 RES lOK OHM l 4W 1 1 0 R074 548 0382 000 RES 12 7K OHM...

Page 60: ...1 1 0 Rl42 548 1147 000 RES 4750 OHM l 4W 1 1 0 Rl43 548 1361 000 RES lOK OHM l 4W 1 1 0 Rl44 540 0936 000 RES 25W lOK OHM 5 1 0 Rl45 540 0912 000 RES 25W 1000 OHM 5 1 0 Rl46 540 0964 000 RES 25W 150...

Page 61: ...THERMISTOR 2K OHM 1 0 R230 R231 540 0970 000 RES 25W 270K OHM 5 2 0 R232 540 0915 000 RES 2sw 1300 OHM 5 1 0 540 0919 000 25W 2000 OHM 5 R233 RES 1 0 R234 R235 540 0916 000 RES 25W 1500 OHM 5 2 0 R236...

Page 62: ...W 82 OHM 5PCT 2 0 R344 R345 540 0920 000 RES 25W 2200 OHM 5 2 0 R346 540 0912 000 RES 25w 1000 OHM 5 1 0 R401 R402 540 0588 000 RES 2W 110 OHM 5PCT 2 0 R403 R404 540 0591 000 RES 2W 150 OHM 5PCT 2 0 R...

Page 63: ...C7906CT 1 0 XF402 XF403 402 0129 000 CLIP FUSE 2 0 XOOOl 404 0674 000 SOCKET IC 14 CONT 1 0 X0002 404 0673 000 SOCKET IC 8 CONT 1 0 X0003 404 0675 000 SOCKET IC 16 CONT 1 0 XU004 XU005 404 0673 000 SO...

Page 64: ...2 000 540 0960 000 540 0869 000 540 0882 000 DESCRIPTION HEAT SINK PAl lCB CRYSTAL 4 0960 MHZ IC TAK 3H PC BD VCO CAP lOOOPF SOOV 20 NUT HEX 4 40 4 SPLIT WASHER BRZ WASHER PLAIN 156 ID NUT WELL 6 32 G...

Page 65: ...BOL ROlO SOOl 7 14 HARRIS PART NO 540 0894 000 604 0852 000 939 6384 001 992 6159 001 Continued DESCRIPTION RES 25W 180 OHM 5 SWITCH ROCKER DIP 4 SPST PWB ASSY VCO MODULE 888 2172 001 QTY 1 0 1 0 1 WA...

Page 66: ...RIS STM 1 AM STEREO MONITOR Figure Title Drawing No Page No 8 1 BLOCK DIAGRAM STM 1 AM STEREO MONITOR 839 6522 001 8 3 8 4 8 2 SCHEM AM STEREO MONITOR Sheet 1 of 2 839 6360 002 8 5 8 6 8 2 SCHEM AM ST...

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Page 68: ...LECTOR FINE FREQUENCY LPF SYNTHESIZER CJ l o LPF RF RF IF I w 90 LPF 1 w IF I LPF AGC HPF L R G PILOT FILTER APF G PLL L R _________ L MATRIX R L R STEREO ISB FIGURE 8 1 BLOCK DIAGRAM STM 1 AM STEREO...

Page 69: ...3 4 o 61 0304 PN4258 18 lS 2N4403 3 INDUCTANCE IS IN UH 2 CAPACITANCE IS IN UF I RESISTORS ARE IN OHMS 1 4 WATT 51 UNLESS OTHERWISE NOTED RIIO 91 Rl33 4020 C58 11200 PF li K Ill C42 7 5 U5 15 TO SH2...

Page 70: ..._ ___ ___ 93307 Ill C RIGHT MODULATION I I I I I I I I IM3 I I I I L __I Jl 27 CRl6 iw R9I IOK 8 i l 2W I t 1 5 1 J i5 Jl 13 Jl 21 Ill L R I IJl 22 I IS6 I I JJ L STEREO ISB 78l Ill CR403 3 4 5 l 2W B...

Page 71: ...29 29 8 IDSI ANODE 12 __ 41 442471ME21 r 1P1 3 3 ILOT I SI MULTIMETER I 45 0 4 0 GND 7 STUD 58 8 i IPl 33 33 io v lPl 36 36 12 II 0 IS2 uTo MONO STEREO I 1 1Pl 32 32 21 IPl 21 _ t lPl l9 19 4 IPl 9 9...

Page 72: ...forms are instructions for making the required measurements Table A 1 Recommended Test Equipment Audio Oscillator Patomac Instruments AG 51 or equivalent Distortion Analyzer Voltmeter Patomac Instrume...

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Page 74: ...level at lkHz OdB d S N is taken at lOOOHz 75 modulation left channel then right channel e The pilot is turned on f Exciter in stereo mode FREQUENCY 400 1000 2500 5000 7500 10 000 HZ RESPONSE dB SEPA...

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Page 76: ...R dB dB Carrier Shift The conditions for this test are a L R 400Hz b 95 modulation c Pilot on d Exciter in stereo mode Carrier shift from Envelope monitor Incidental Quadrature Modulation The conditio...

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Page 78: ...envelope or maximum attainable d Reference level is the level at lkHz OdB e The pilot is turned on f Exciter in stereo mode FREQUENCY Hz RESPONSE dB DISTORTION 50 100 400 1000 2500 5000 7500 10 000 12...

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Page 80: ...Reference level is lk Hz OdB d S N taken at lOOOHz 75 modulation left channel e Pilot on f Exciter in stereo mode FREQUENCY Hz RESPONSE dB DISTORTION 400 1000 2500 5000 7500 10 000 12 500 15 000 L R L...

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Page 82: ...the exciter into STEREO mode 10 Measure desired parameter A 5 For the purpose of establishing an accurate level of modulation use the station s AM modulation monitor As a comparison the ENV position o...

Page 83: ...LEFT BNC or rear panel barrier strip for left channel residual signal LEFT BNC or rear panel barrier strip RIGHT BNC or rear panel barrier strip LEFT BNC or rear panel barrier strip for LEFT channel...

Page 84: ...1 for the desired pilot injection level See Table 3 4 in the STX 1 technical manual for location details A 8 The stereo measurements are measured at three 3 different levels of modulation 25 50 and 7...

Page 85: ...rtion analyzer audio voltmeter input is connected to the AM Stereo Modulation Monitor I inphase BNC on the front panel or I channel output on the rear panel barrier strip The Q quadrature signal from...

Page 86: ...zer audio voltmeter to the audio output port of the station s AM envelope modulation monitor 2 Without audio applied to reference point on the monitor the system station s AM establish envelope a carr...

Page 87: ...increasing or decreasing the audio drive level from the signal generator in order to obtain the same modulation level established as the reference will be the indication of system response If the audi...

Page 88: ...EFT and RIGHT channel stereo signal to noise measurements are taken at 400 Hz and 75 modulation only After establishing the proper level of modulation with the exciter in the MONO mode switch to STERE...

Page 89: ...measured on LEFT and RIGHT chan nels in stereo at a maximum modula tion of 75 and the main or LEFT equal to RIGHT and SUB or LEFT equal to MINUS RIGHT at aximum of 95 modulation The stereo LEFT and RI...

Page 90: ...nvelope detector of the AM modulation moni tor thereby removing the ability to measure the amount of modulation As outlined in paragraph A 4 the Am Stereo Modulation Monitor may be used to monitor the...

Page 91: ...ies to be used are 50 Hz 100 Hz 400 Hz 1 000 Hz 5 000 Hz and 7 500 Hz MEASUREMENT RESPONSE MONAURAL Specifications 2 dB as referenced to an audio drive signal of 1 000 Hz METHOD The system response me...

Page 92: ...to be in creased to overcome the roll off attenuation presented by the system If the audio drive had to be re duced below the banchmark value then the dB difference will be noted as a plus value The d...

Page 93: ...peak Q signals as derived from the STM 1 Divide the I peak to peak into the Q peak to peak value take the log10 of the resultant then multiply the log10 ratio by 20 to arrive at the IQM of the system...

Page 94: ...upply ripple asymmet rical load or loads High Q tuned traps ground loops efficiency resona tors and low emission tubes A 28 During the coarse of time as each of the above are eliminated as a problem g...

Page 95: ...hird 3rd harmonic of the fundamental operating frequency listening for the modu lating tone and determining the quantity of the received spurrious or harmonic signal as referenced to the fundamental s...

Page 96: ...n 6 and 7VDC The following table serves as a guide in setting the VCO inductors Note Open Closed EXAMPLE SWITCH Sl Frequency KHz Sl S2 S3 S4 l 0 500 1 1 1 1 600 l 1 1 1 700 1 1 1 0 800 1 1 1 0 900 1 l...

Page 97: ...itions for S301 in this case Sl O so S301 switch number l should be switched to closed position away from OPEN nomencla ture on switch S2 1 so S301 switch position number 2 should be switched to OPEN...

Page 98: ...902 0 0 0 I 0 0 0 1 0 541 8 13 0 I 0 I 0 0 0 0 I I 647 90 S 0 0 0 0 0 0 I I 548 804 0 0 0 0 0 0 0 I 0 0 648 904 0 0 0 0 0 0 0 549 BO 0 0 0 0 0 0 0 0 I 649 905 0 0 1 0 0 0 0 l 150 11 b 0 0 0 0 0 0 0 I...

Page 99: ...I 0 747 1003 0 0 0 0 0 0 0 1 1 847 1103 0 0 I 0 0 0 I I 748 1004 0 0 0 0 0 I 0 0 848 1104 0 0 0 0 I 0 0 I 74 1 1005 0 0 0 0 0 0 I 0 I 849 l 10l5 0 0 0 I 0 1 750 1006 0 0 0 0 0 0 I I 0 8 10 1106 0 0 0...

Page 100: ...0 0 0 0 0 I I 9 48 1204 0 0 0 0 0 0 0 10 48 1304 0 0 0 0 0 0 0 I 0 0 949 1205 0 0 0 0 0 0 I 1049 130 5 0 0 0 0 0 0 0 I 0 I 9 S0 1206 0 0 0 0 0 I I 0 10 50 1306 0 0 0 0 0 0 0 I I 0 9 51 1207 0 0 0 0 0...

Page 101: ...403 0 0 0 I 0 0 0 0 I I 1247 1 503 0 0 0 0 0 0 l I 1148 1404 0 0 0 I 0 0 0 I 0 0 1248 1 504 0 0 0 0 0 l 0 0 1 149 140 0 0 0 1 0 0 0 I 0 I 1249 150 5 0 0 0 0 0 I 0 I llSO 1406 0 0 0 I 0 0 0 I I 0 12 lO...

Page 102: ...0 0 0 0 0 1349 1605 0 0 0 0 0 0 0 0 I 1449 1705 0 I 0 0 0 0 0 I 13 SO 1604 0 0 0 0 0 0 0 I 0 1450 1706 0 I 0 0 0 0 I I 0 1351 lb07 0 0 0 0 0 0 0 I I 1451 1707 0 1 0 0 0 0 I I I 13 12 lb08 0 0 0 0 0 0...

Page 103: ...l 0 0 1648 1904 0 l 0 0 I 0 0 1 149 180 5 0 0 0 0 0 1 0 1 1649 1905 0 1 0 0 I 0 I 1 0 1B06 0 0 0 0 0 1 l 0 l6SO 1906 0 1 0 0 l 1 0 15 5I 1807 0 0 0 0 0 I I 1 t6SI 1907 0 I 0 0 l I I 1 5 2 1B08 0 0 0...

Page 104: ...1977 0 0 0 0 I 0 I I I 1722 1978 0 0 0 0 I I 0 0 0 1723 1979 0 0 0 I 0 I I 0 0 I 1724 1980 0 0 0 I 0 0 0 0 0 17 1981 0 0 0 0 0 0 0 I 1726 1982 0 0 0 0 0 0 I 0 1727 1983 0 0 0 0 0 0 I I 1728 1q94 0 0 0...

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Page 106: ...NTRODUCTION APPENDIX C COMPONENT OUTLINES c 2 This appendix contains component outlines for selected electrical components used in the STM 1 AM STEREO MONITOR 888 2172 001 C 1 C 2 WARNING Disconnect p...

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Page 108: ...0 NOH INY UITtHO r ili 9 T I _ TA Cl a a R IC MC10178L INVIIITltfQ IH T NON INVIHING IC NE5532AN IC LM318 S2 02 S3 03 6 41 5 2 s s a 01 a 01 Ct a C1 a a a R Fl I 3 03 fin LO 28 2 Vss OSCin 27 J Voo OS...

Page 109: ...N NC NC vcc Triple 2 Channel Analog Multiplexer Demultiplexer 6 11 Control 10 9 f 13 SwitCMt 2 In Out I 5 3 lC V z v0 o Pin us v 55 Pin a VEE Pin 7 14 15 4 Commons Out 1n IC CD 4053BE MC14053B IC 74L6...

Page 110: ...6 7 C 1st Crour1d 2 2 5 6 1 NOTE PIN J ANO 4 MU T ll CONN CHD ro UH R MIXER DOUBLE BAL TAK 3H 888 2172 001 LOGIC SYMBOL f 11CIO 0 Pin 4 11C I Q Pin 3 Vee Pin 4 VcCA Pin 5 Vu Pin 12 Vu ITTLI Pin 13 II...

Page 111: ...eration of the Harris system in any way Tools and Test Eauipment Required Low wattage soldering iron for PC board work small hand tools frequency measur ing device audio generator Time Required pproxi...

Page 112: ...d for 25 Hz as observed on the frequency measuring device 8 Compare the present modulation meter reading of the Exciter with the reading recorded in step number 1 above If necessary adjust Rl52 Pilot...

Page 113: ...rs are 1 4 watt 5 5 Locate IC s numbered U22 U23 U24 and U25 Pay careful attention to how pin Ill is identified on the IC s and then remove them from their sockets and set them aside Refer to PC board...

Page 114: ...ing the reverse of the procedure outlined in step 3 10 Take the monitor to it s working location and make all the appropriate connections but leave the top cover off of the unit 11 Restore AC power to...

Page 115: ...llows 90 VAR to 90 STEREO AUTO MONO to STEREO STEREO ISB to STEREO 16 Apply a lKHz LEFT only audio tone to the exciter Adjust the audio input level to obtain a LEFT meter reading above mid scale 17 Se...

Page 116: ...is decoder board NOTE These capacitors were not included in the 25HZ modification kit but can be acquired from Harris upon request Harris Part 506 0244 000 Quantity 2 Motorola Decoder Boards The follo...

Page 117: ...hat the following modification can be made to the receivers to achieve better high end response Cut the following capacitors out of the receiver circuit C32L C32R These capacitors can be found in the...

Page 118: ...www SteamPoweredRadio Com t u Q ln r _ er C E I CJ D _ 0 t 0 V AM 198 JRN Page 8 l n I t J s 0 CT J Ul 1 n I...

Page 119: ...wing No Changes 7 4 Change line C017 from 526 0331 000 cap 33 uf 35V 20 to 526 0050 000 cap 1 uf 35V 20 7 7 Change R006 R007 from 540 0958 000 resistor lz watt 82K ohm 5 to 540 0967 000 resistor watt...

Page 120: ...may be removed after correctiOl S have been made Thank you for your cooperation Page Drawing No Changes 7 7 R021 from 540 0919 0CO resistor watt 2000 ohm 5 to 540 0937 000 resistor watt llK ohm 5 R02...

Page 121: ...is addendum insures you that the latest improvements have been incorporated in your equipment This way we can provide up to date information without a delay due to printing new instruction manuals Ple...

Page 122: ...to date information without a delay due to printing new instruction manuals Please make the necessary corrections as listed below Please use ink for a permanent record r This addendum may be removed...

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