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Страница 1: ...Steam Powered Radio Com I I I I I OPERATING MAINTENANCE INSTRUCTION MANUAL MODEL 705 FM FMX STEREO GENERA ...
Страница 2: ...d Radio Com USER S RECORD Model 705 Serial No Date Purchased Warranty Card Returned Purchased From INSTRUCTION MANUAL MODEL 705 I FM FMX STEREO GENERATOR March 1988 1305 Fair Avenue Santa Cruz CA 95060 408 458 0552 ...
Страница 3: ... 3 9 SETUP AND OPERATION 13 Panel Controls Setup Procedure Composite Equalization Adjustment CALIBRATION Equipment Required Visual Inspection Strap ping and Presets Power Up Input Gain Highpass Filter Preemphasis Filter Tuning Overshoot Compensation Adjustment Crosstalk Trim FMX Plug In Option Calibration Final Level Setup CIRCUIT DESCRIPTIONS Input and Preemphasis Stages Filter Overshoot Compensa...
Страница 4: ...on system Audio Pre Processing Requirements Though overmodulation protection circuitry is included in the 705 it is anticipated that the Generator will be preceded by some form of audio processing system which places a ceiling on program peaks with specific allowances for protection of the preemphasis characteristic It is essential that this need for split spectrum audio processing be understood a...
Страница 5: ...tive peak QliEE integral with the filter overshoot compensator Because of its unique mode of operation a good deal more peak clipping may be tolerated than with more simple signal clipping circuits The 705 may in fact even be used barefoot or with minimal audio pre processing yet still yield quite acceptable and competitive performance About FMX FMX is the tradename for a patented improved system ...
Страница 6: ...r exceed the usual 100 value of the interleaved stereo signal The FMX compression function is graphed in Figure 1 40 V V 30 Figure 1 i I 8d8 SPEC t_ V os l7 s r I V 14d8 v V s 20 10 OdB INPUT 10 V IOOOi MOO OdB 10 20 30 40 10 0 u T p u T FMX COMPRESSION CHARACTERISTIC S compressor IN vs OUT relative to S The FMX receiver has a dual demodulator which independently recovers program information from ...
Страница 7: ... 19kHz Distortion 0 1 THD in baseband and subcarrier at 90 modulation NQi below 100 modulation Pilot OFF 75dB or better in baseband and subcarrier 38kHz residual and digital noise above 54kHz 60dB or better Stereo Separation Better than 55dB 25Hz 5kHz better than 50dB 5kHz 16kHz Crosstalk M S or S M better than 60dB EilQt 19kHz lHz 2 THD distortion products better than 55dB below 100 modulation Pi...
Страница 8: ...iliary plug in circuit board with all parameters preset Power Requirement 105 130 or 205 255VAC 50 60Hz 8 Watts Size gnd Y J gh t 1 3 4 x 19 x 8 lU 8 lbs Block Diagram A simplified block diagram of the 705 Stereo Generator is shown on Page 8 Generator circuitry is explained in detail under Circuit Descriptions Section V which reference the complete set of schematic diagrams contained in the Append...
Страница 9: ... ICI3A I4A I5A 9A I I Q7 12 I6A 17A I8A 19A co 3 0 0 l l I I 7 r I J 0 I 01 R L FMXTM o s 16KHZ EQ C l o 3 l l 0 l l 0 SUMMER COMPRESS COMP LPF SUMMER ICI2B 14 15 hl r r l C L 0 l l z l l 0 ICIB ICIA 213B IC3A 5 6 7 ICB 91 I0 118 tICl2A C 4j Ql 4 o 13 I0HZ 608 KHZ o 3 0 0 IOHZ CONTROL GEN LOGIC ICIIA ICIBB 221 231 24 IC161 17 I8A 19 20 21 FMX PLUG IN OPTION ASSY J i COMPOSITE OUTPUT I I S CLIP ILo...
Страница 10: ...fic SERVICE OR MODIFICATION INSTRUCTIONS should they be issued by the factory The Inovonics 705 is packaged to mount in a standard 19 inch equipment rack and requires only 1 3 4 inches lU of vertical rack space The 705 generates negligible heat and itself is unaffected by wide variations in ambient operating temperature AC Power Unless specifically ordered for export shipment the 705 is delivered ...
Страница 11: ...mately be returned to earth ground for safety LINE INPUT and Range Selection The Model 705 has electronically balanced transformerless bridging 10k ohms or greater LEFT and RIGHT LINE INPUTS These are brought out to the rear panel barrier strip and include chassis ground connections for cable shields Should the equipment which fggg the Generator require output loading 600 ohm terminating resistors...
Страница 12: ...ic A 75 ohm buildout resistance is provided however and may be placed in series with the Lo Z output when the 705 is presented with complex reactive loads which might otherwise cause the output stage to become unstable A short coaxial cable pigtail runs from the rear panel COMPOSITE OUTPUT jack to a connector strip located beneath the top cover between the PILOT and COMPOSITE LEVEL controls The en...
Страница 13: ...ble pigtail to the left Remove the dummy plug from the FMX accessory socket and insert the ribbon cable connector The cable has been preformed and there is only one way it can be plugged into the accessory socket This completes installation of the FMX option Be sure to save the dummy plug it can be stuck to the inside of the top cover with a length of masking tape PAGE 12 ...
Страница 14: ...cursions even when a complex input signal _ __ has been pre limited This circuit establishes a maximum value for input signals and maintains this level for all program components effectively eliminating the tendency of the filter to overshoot the amplitude constraint The switch is turned OFF only for testing or as otherwise necessary to modulate the transmitter in excess of 100 LEFT and RIGHT INPU...
Страница 15: ...d audio processor As explained on Pages 3 and 4 the processor should maintain program peaks at a ceiling value corresponding to 100 modulation and incorporate preemphasis protection independent high frequency limiting in addition to broadband peak control The Procedure also assumes direct connection of the 705 output to the composite broadband input of the transmitter or exciter Variations from th...
Страница 16: ...cally 8 10 Composite Equalization Adjustment OPTIONAL Provision has been included in the 705 for limited equali zation of the composite output signal The adjustment is optimized at the factory for best stereo separation based on the oscilloscope method of measurement at the 705 COMPOSITE OUTPUT connector It is possible however to readjust the EQ to correct for other transmission system response de...
Страница 17: ...ical sensitivity of the scope to resolve flatness of the baseline NOTE some oscilloscopes will show erroneous distortion at the baseline when severely overdriven Watch for an abrupt change at the baseline as the vertical sensitivity is progressively increased ie a change in flatness which does IlQ correspond to a step increase in the vertical gain Keep gain below such an overload point 5 As R188 i...
Страница 18: ...nd that an FMXM dummy plug is inserted in the Jl socket 3 STRAPPING AND PRESETS A Set all front panel slide switches OFF and turn all front panel controls fully CCW B Center all single turn circuit board trimpots C Move Input Gain Jumpers to L and Preemphasis Jumpers to 75 Output Characteristic Selector to LO Z 4 POWER UP A Turn POWER ON and check the 15 volt and 6 volt supplies The left hand end ...
Страница 19: ... lkHz the traces should remain superimposed with flat amplitude response to abotlt 12kHz with filters unadjusted Sweeping the oscillator frequency downward from lkHz should show flat frequency and phase response to 25Hz the amplitude dropping abruptly below 20Hz E Turn PRE EMPHASIS ON and again sweep the oscillator upward from lkHz The traces should remain superimposed and increase to 2 volts p p ...
Страница 20: ...e upper graticule division as the right hand hump is above it D Increase the oscillator frequency to 15kHz and adjust R55 and R83 for exactly 3 divisions p p FOLLOWING THIS RESET SCOPE ATTENUATORS TO THEIR CAL POSITIONS 8 CROSSTALK TRIM A Connect the COMPOSITE OUTPUT of the 705 Generator gir 11Y to the vertical input of the scope using a short BNC to BNC cable Apply a lkHz l0dB oscillator signal t...
Страница 21: ...nerator used for calibration of the FMX plug in has itself undergone calibration to this point in the Procedure A Visually inspect the plug in circuit board for workmanship and orientation of polarized components All ICs face the rear of the Generator except for the 24 pin CD4059 which faces left NOTE Unless otherwise specified all test points TP1 TP3 etc and trimpots R9 R57 etc refer to the FMX p...
Страница 22: ...djust R63 for a null d Reset the oscillator frequency to exactly 34 570Hz and adjust R51 for a null e Remove the ground strap from the CD terminal E Overshoot Compensator Adjustment a Feed the lkHz oscillator signal to the Left Channel Line Input of the 705 Generator terminal and Ground Monitor TP5 of the main 705 circuit board with a probe connected to Channel A of the scope Monitor TP5 of the El...
Страница 23: ...nd the PILOT switch ON Adjust PILOT LEVEL for 0 25 volts p p on the scope monitoring the COMPOSITE OUTPUT D Reconnect the lkHz oscillator signal and with the PILOT ON fine adjust the COMPOSITE LEVEL control for a total p p output amplitude of 3 0 volts E Set the oscillator output level to exactly lOdB Set both INPUT GAIN controls so that the INPUT CLIP LEDs just come on The COMPOSITE OUTPUT signal...
Страница 24: ...p I Remove the oscillator signal and turn the FMX switch back ON Adjust R 0 on the plug in board for a l0Hz modulated DSB S FMX Pilot signal of 0 03 volts p p in the monitored COMPOSITE OUTPUT signal WHEN ALL LEVEL SETUP IS COMPLETE J Connect the COMPOSITE OUTPUT of the 705 Generator to a suitable Stereo FMX demodulator and with PRE EMPHASIS turned ON test operation in all modes with actual progra...
Страница 25: ...ity of the unit over the 15dB ranges selected by the two input gain jumpering options The highpass function has flat response down to 25Hz but substantially attenuates subaudible components of the input program signal which could upset the AFC circuits in certain FM exciters IC2A is a third order lowpass filter with flat response to about 20kHz It was included to help cope with out of band digital...
Страница 26: ...imate program waveshapes They instead catch fast peaks which either have evaded the limiter or have been aggravated by phase shifts in the input and preemphasis stages IC6B is a phase lgg circuit which time displaces the fast leading and trailing edges of steep waveforms Thus the primary characteristic of a program wavefor m which would normally gi1 filter overshoots is instead added to the wavefo...
Страница 27: ...hed by McGraw Hill In his book the FDNR filter is called a GIC or Generalized Impedance Converter Whatever IC19B buffers the output of the lowpass filter and provides gain to make up filter loss The signal level at TP5 corre sponding to 100 modulation is about 8V p p Subcarrier and Pilot Generation Schematic on Page 40 The filtered Left and Right channel program signals are fed to the ends of resi...
Страница 28: ...pulse and restart the entire sequence With the MODE switch S3 in MONO ICs 28C and 29A interrupt clock pulses to the shift registers the next instant the circulating 1 reaches the Q3 output of IC23 This stops the sine sampling at precisely the center of the resistor string and yields an L R MONO output The stereo Pilot signal is generated in an identical manner except that clocking is at the 304kHz...
Страница 29: ... which might drive this stage nuts fQN Q HHlY Schematic on Page 41 A circuit board jumper makes either parallel or series connection to the Tl power transformer primaries for 115 or 230 volt AC mains Three terminal IC regulators supply the four regulated DC voltages Program signal stages utilize bipolar 15 volts and CMOS digital circuitry operates from a bipolar 6 volt supply to accommodate ground...
Страница 30: ...rectified difference signal IC4A forms an active clamp to keep the output of IC4B from going at all positive even as the difference signal continues to increase R29 scales the control DC to the pinch off voltage of the particular FETs used also setting the FMX Compression Threshold Transfer characteristics of this feedforward circuit would be more abrupt than the specified reentrant function were ...
Страница 31: ...a simple 3 pole lowpass filter which supplies a quite pure l0Hz Pilot sinewave To be perfectly honest the FMX Pilot is not exactly l0Hz Rather it is an even numbered division 1 920 of the 19kHz Stereo Pilot or 9 8958333Hz This error was purposely introduced to support the phase lock Pilot recognition circuits of some FMX receivers The l0Hz Pilot is combined with the S signal at the input of IC13A ...
Страница 32: ...Steam Powered Radio Com VI APPENDIX Parts Lists Schematics Warranty PAGE 31 ...
Страница 33: ...minibox format with 0 2 inch lead spacing C7 20 34 40 42 49 51 C33 52 53 59 60 68 69 71 72 74 75 C41 50 61 C57 C70 73 C76 77 CRl 10 13 16 CRll 12 CR17 24 Indicators Il 8 10 12 12 7 9 11 I3 5 I4 6 1086 1088 1060 1005 0902 1064 1100 1127 1125 2021 2022 2023 2024 Polypropylene 0033uF 2 5 100V WIMA FKP 2 Electrolytic High Reliability 2 2uF 50V ILLINOIS CAP 225RMR050M Electrolytic 4 7uF 25V open radial...
Страница 34: ...MOS Quad AND CD4081BE open CMOS Quad OR CD4071BE open CMOS Hex Inverter CD4069UBE open Dual High Speed Op Amp LM833N NATIONAL Pos Volt Reg LM317T open Neg Volt Reg LM337T open NPN High Beta 2N5088 open PNP Gen Purp 2N3906 open NPN Med Power MJE340 open PNP Med Power MJE350 open UNLESS NOTED BELOW fixed resistor values are per schematic notation in ohms K Xl000 M XlMeg With no tolerance specified r...
Страница 35: ... P N Dual Primary PC mounting TRIAD FP34 340 SIGNAL LP 34 340 Crystal 1 216MHz INOVONICS ONLY Dummy Plug for FMXTM Accessory Socket INOVONICS ONLY 8 Position Female Jumper Strip for Mains Voltage Selection 0 1 inch spacing Shunt Jumper to set Input Gain Preemphasis Silicone Rubber Insulating Washer for TO 220 Voltage Regulators Fiber Shoulder Washer for mounting TO 220 Voltage Regulators PAGE 34 ...
Страница 36: ...ivalent minibox format with 0 2 inch lead spacing C12 1060 C17 21 22 23 24 1088 Diodes CRl 6 8 12 CR7 1100 1104 Integrated i i1 ICl 3 5 6 8 11 13 IC4 7 IC12 14 15 IC16 17 IC18 19 22 23 IC20 IC21 IC24 Transistors Ql 2 Q3 4 1375 1313 1335 1301 1322 1342 1338 1350 1234 1210 Electrolytic 4 7uF 25V open radial Electrolytic High Reliability 2 2uF 50V ILLINOIS CAP 225RMR050M Silicon Signal 1N4151 open Si...
Страница 37: ...tion in ohms K Xl000 M XlMeg With no tolerance specified resistor is 5 1 4 watt carbon film 1 resistors are 1 4 watt metal film Variable resistors with front panel access are multiturn type BECKMAN 89PR series value per schematic other trimpots are single turn type BECKMAN 91AR series value per schematic Miscellaneous 182100 Interconnect Pigtail Cable Assy FMX Plug In to Main Board INOVONICS ONLY ...
Страница 38: ...K Cl5 IOOP R29 150K RJZ Ci4 2K IOOP B_ INPUT GAIN R3J J9 J Rl7 JOOK C9 68P 1 Cil 220P 220P RIB c 4 7K R20 IOK Ci2 D22J 50 RJ8 JOCK C22 68P R41 IOK C25 022T 650 7 C24 220P TPI A P2 I 15V j 6V i 6V 15V f r0 TP 2 I 8 P2 PRE EMPHASIS P O FMX OPTICN OFF OH SOCKET ALSO ON P4 P5 I2 PAGE 37 705 u Ct 1 f C lO JIM 7 J0 87 JJ 1 to r SCHEMATIC fCk tAANCII WAffki t 4 fl N _ 01 FM STEREO GEN _ s _MO 1s1500 l A ...
Страница 39: ...OOK CR4 CR8 R78 IOK 1 R77 IOK R91 R98 IOOK IOOK C32 I R92 R99 IOOK IOOK R53 IOK 1 7 R52 IOK1 1 R67 51K RSI IOK lo o R66 3 3K R94 3 3K R54 IOK 1 R56 IOK 1 7 RIO6 IOK lo o 705 TOllllAHCII Jl l t 0 1 w l WI AHOUI 1 TP3 C P3 REF F P5 RE E P5 RIOI 5 6K RIO2 IK RlO5 IOK 196 RIO4 CD 22OK c33 r0 2 2 I 0 OFF ON Q St JQQI C QMB Q P3 j 15V TP4 j GV GV I i 15 PAGE 38 _JIM 7 31 87 i s CHtC a u _ OVt U SCHEMATI...
Страница 40: ...1C52 i 6V I I CD I 3 34 570 I 19 1 10 2 21J80 i 6V f Rl31 Rl37 Rl43 Rl49 I I 3570 lo o 4640 lo o 40201 1 261 0 1 D P2 J 15V C53 C43 Rl32 Rl38 Rl44 T22 0033 536 lo o 2740 1 19101 lo o I cso C44 C46 C48 4 7 0033 0033 0033 I TP6 H P4 I C45 C47 C49 0033 0033 0033 Rl34 RISO I 3 3K 300K RISI 15K CSI 0033 Rl35 Rl47 Rl52 I IK IK 5 6K I Rl42 Rl48 Rl36 3010 1 4 30101 lo o 3010 1 I PAGE 39 I I JIM 8 4 87 l i...
Страница 41: ...I CR c59 12 2 C60 IC20B 12 2 J P5 If IC21 22 30 31 TYP 7 YI D l 216MHZ Rl78 IOOK TP9 IC37 14 B Q 12 R 10 Qt A Q2 R 4 MONO 4 C STEREO OFF ON 8 16 e IC32 IC33 C 11 SL 7 SRt 2 so 9 J SI 10 I A IC27A Rl76 IOOK 3 Rl72 15K IC34 14 B C56 T6r 8_P_____ IC35 7 IC29C Rl77 IOOK I 0 I t 15V i 6V 705 lOllkAHCt S 1f l 01 l L UOo AMt Lll l JIM 8 7 87 CH 1 t t l J i 6V i 15V PAGE 40 SCHEMATIC MA Tf Fl Ail J 1 FM S...
Страница 42: ...K I I C69 r2 2 _ r I 15V 6V I IC39 IC40 I I FMX OPTION SOCKET R200 R202 ALSO ON P1 14 220 220 CRl 7 CRIB I C10 c11 R20I en 8 1000 Rl99 CRl9 CR20 2 4K 2 2 820 2 2 1 115V POWER I ON l Off I 230V I C74 C75 0 R203 CR23 R205 CR24 S6 Tl c73 2 4K 2 2 820 2 2 1000 R204 R206 I CR21 CR22 220 220 Mt MAINS AC I IC41 IC42 I 15V 6V PAGE 41 705 JIM 7 87 IN0V0NICS CHU a 1 0 O fkD SCHEMATIC 1 1 TOl ll lAJIIC MATUh...
Страница 43: ...033 R62 2 2K CR8 R28 IOK 2 21 780 R63 IK CR9 R29 IOK 7 I R59 4020 lo o R54 2740 1 C9 0033 R56 2K R58 3010 10 4 CR7 6 2V 1 19 110 R53 4640 1 fl34 IOK CRIO R44 IOK lo o R45 IOK 1 CRII l I R43 IK R47 3570 1 RJS IOK 1 R40 IOK I C5 0033 R46 300K j 15v t 1 5v R41 IOK11 lt __ _j I C I I I PAGE 42 705 _ IM 12 1 87 t c 0 __ SCHEMATIC TOLIA4NC r S IU TIJUAL HJr Ul H 1 L 01 lf l 001 L U 1 FMXTM OPTION PAuf M...
Страница 44: ... 10 b R85 576 1 16 1 5 ao R86 14 QI 487 1 1 302 12 Q3 R87 ICl50 3 00 324 4 DI 1 02 6 03 R88 8 115 lo o ICl28 14 B 7 IC22 14 B 58 7 ICl6 C II SL 7 ICl9 14 SR 2 t t 1 1 Q so 9 SI 10 I IC 17 C II SL 7 SR 2 so 9 SI R Ci9 T6BP 2 A 4R B 1 R90 IOOK CR 12 58 IC 21A 93 C21 2 2 C22 2 2 C23 2 2 C24 2 2 23 OUT 22 J5 21 J6 J7 19 JS IBJg 17 JIO 16 JII 15 Jl2 14 KA 13 B 1 2 705 _JIM u 1 c u 1IOVI O TOl l A lofCU...
Страница 45: ...responsibility of the purchaser to return equipment for warranty service to the dealer from whom it was originally purchased unless prior arrangement is made with the dealer to inspect or repair at the user s location This warranty is subject to the following conditions 1 Warranty card supplied with the equipment must be completed and returned to the factory within 10 days of purchase 2 Warranty i...
Страница 46: ...Steam Powered Radio Com 1 I I I I I I I I I I I I I I I I I I ...
