Acoustical Manufacturing Co. QUAD MULTIPLEX DECODER Instruction Book Download Page 16

�uarantee 

T his  instrument  is  guaranteed  against  any  defect  in  materiaL  or  workmanship  for  a  period  of 

twelve 

calendar  months  from  the  date  of  purchase. 

Within  this  period  we  undertake  to  supply  replacements  free  of  charge  ior  any  parts  excepting  valves 

(which  are  covered  by  the  makers'  guarantee  of  three  months)  which  may  prove  on  examination  to  be 

defective,  provided  that  such  defectiveness  is  not  the  result  of  misuse  (including  use  with  unsuitable  ancillary 
equipment),  accident  or  negligence,  and  further  that  the  instrument  was purchased at the proper consumer price 

prevailing in the country  of purchase. 

Any  set  requiring  service  under  this  guarantee  should  be  taken  to  the  supplier  through  whom  it  was 

purchased,  or,  in  case  of  difficulty,  it  should  be  carefully  packed  and  consigned,  carriage  paid,  to  the  mairl 
distributor  for  the  country  of purchase.  It must  not  be sent  to  any  other  agent  or  distributor  except  by  special 

arrangement. 

This  guarantee  is  valid  only  when  the  enclosed  card  is  properly  filled  in  and  returned  for  registration  as 

directed  within  ten  days  of  purchase,  and  does  not  cover  labour  or  carriage  costs  involved  in  any  repair  under 

the guarantee. 

Page  16 

ACOUSTICAL  MFG.  CO.  LTD., 

HUNTINGDON,  ENGLAND. 

Summary of Contents for QUAD MULTIPLEX DECODER

Page 1: ...INSTRUCTION BOOK QUAD MULTIPLEX DECODER ...

Page 2: ...THE ACOUSTICAL HUNTINGDON TELEPHONE 2561 2 MANUFACTURING HUNTS CO LTD ENGLAND TELEGRAMS ACOUSTICAL HUNTINGDON Issue 2 I m 1 0 65 ...

Page 3: ...mits of audi bility The listener with a mono receiver is therefore not aware of the stereo information The purpose of the multiplex decoder is to translate these inaudible difference signals and to com bine them with the sum signal in such a way that the original left and right hand channels re appear separately THE QUAD MULTIPLEX DECODER The QUAD multiplex decoder is designed specifically for use...

Page 4: ...esistors R20 220K R21 100K and capacitor C34 lOOOp 3 Connect the Brown audio lead via a 2 2K resistor Dubilier BTT or equiva lent to pin 5 of valve V6 6AL5 Keep the resistor close to pin 5 see fig 2 Connections between units The FM tuner Multiplex Decoder Quad 22 control unit connections are shown in fig 3 The Multiplex Decoder may be fitted on the rear of the Quad FM tuner cover by removing the t...

Page 5: ... UAD F M TUNE R A80 JE SE A No l tOIo2 __ ______________________ RED Page 4 FIG I POSITION OF SI WHEN TUNER IS USE D WITH MUL TIPL E X DE COOE R QUAD FM TUNE R BELOW SER No lOb I IG 2 ...

Page 6: ...ET MUL IPl tX F M TIINE R DE CODE HT LT PLUG TO DECODER SaCKET WHlfE PLUG TO LEFTt 3 t 3 t 3 CHANNEL RADIO I RED PLUG TO RI OHT CHANNEL R DIO I FIG 3 YELLOW HT LT PLUG TO YE LLOW SO KEJ BLUE HT LT PLUG TO BLUE SOC KET FIG Page 5 ...

Page 7: ...casts being transmitted within range at that time Long Distance Reception Fading and background n0ise are more apparent when receiving stereo transmissions from distant stations The stereu information is degraded more than the mono channel so that fading and background noise if obtrusive may be reduced by reverting to Mono reception Page 6 SPECIFICATION De emphasis 500S European standards 750S Nor...

Page 8: ...um and difference signals is restored by subtracting 1 2 T times the sum signal from each channel the necessary reversed phase signal being taken from the input stage collector circuit A tuned circuit in the input stage collector feeds the 19Kc s pilot tone to the pilot tone amplifier OC8l The push pull output of this stage is rectified 2 x 1 S920 in order to bias the diode signal switches 4 x IS4...

Page 9: ...odulation level of the left or right tones 400 1000 c s should be 20 30 The FM tuner should be exactly in tune during alignment 1 Connect the decoder to a Quad 22 and two power amplifiers in the normal way but leave the FM tuner signal and HT LT leads disconnected Switch the Quad 22 to STEREO RADIO and run for 30 minutes to allow the decoder to reach operating temperature 2 Switch Quad 22 to 2 MON...

Page 10: ...ith left hand tone Switch Quad 22 filter to 25 at 10 Kc s Connect AC meter across left hand power amplifier output set volume control to give 1 to 5 volts output Adjust L4 slightly for maximum output 6 Transfer meter to right hand amplifier out put and adjust RVl for minimum output about 35db below left hand 7 Modulate signal generator with right hand tone Check that right hand output is at maximu...

Page 11: ... o 0 c 0 3 C r I r m X 0 m 0 0 m l I 0 3 0 z m Z I r 0 C I C Z 0 m l VI 0 m I R2 c91 0 RVI I rl tH l R25 f 1R27 1r 1 I _ R C2 MRII ...

Page 12: ... 1r c 1 C l l FtC 40COrE IJIIIlPHII j L______________________________________________________________________ J T II I2 I I f 5bo0p c lI D fI CRICI S TAtJQfli1 QUAD MULTIPLEX DECODER CIRCUIT DIAGRAM Page 11 ...

Page 13: ...Dubilier BIT 244 B R8 220 10 Dubilier BIT 285 A R9 68K 100 0 Dubilier BIT 205 B RIO 3 3K 10 Dubilier BIT 244 B Rll 2 7K 100 0 Dubilier BIT 248 D R12 22K 10 Dubilier BIT 217jA R13 390 10 Dubilier BIT 275 A R14 330K 10 Dubilier BIT 179 B R15 330K 10 Dubilier BIT 179 B R16 68K 10 Dubilier BIT 205 B R17 33K 100 0 Dubilier BIT 209 D R18 330K 100 0 Dubilier BIT 179 B R19 330K 100 0 Dubilier BIT 179 B R2...

Page 14: ...wyn F20 Welwvn F20 Welwyn F20 Welwyn F20 Welwyn F75 Welwyn F75 Dubilier BIT Egen 195 TCC Metamold M 974 9 TCC E 1072 9 SaJford PF 125V TCC 25V E 1072 f7 Salford PF 125V Salford PF 125V Part of L3 TCC Metamold M 974 12 Salford PF Part of L3 SaJford PF 125V Salford PF 125V Hunts BDIIA Hunts BDIIA Hunts BD72A Hunts BD72A TCC PMX 4 TCC PMX 4 TCC PMX 4 European Standards t North American Standards I St...

Page 15: ...R3 Mullard OC81 MR1 Texas Instruments lS920 MR2 Texas Instruments IS920 MR3 Texas Instruments IS44 MR4 Texas Instruments lS44 MR5 Texas Instruments lS44 MR6 Texas Instruments lS44 MR7 Texas Instruments lS44 MR8 Texas Instruments lS44 MR9 Texas Instruments lS44 MRlO Texas Instruments lS44 MR11 Texas Instruments lS2075 MR12 Texas Instruments lS2075 L1 Acoustical Drg Al1697 Issue 4 750 A L2 Acoustica...

Page 16: ...at the instrument was purchased at the proper consumer price prevailing in the country of purchase Any set requiring service under this guarantee should be taken to the supplier through whom it was purchased or in case of difficulty it should be carefully packed and consigned carriage paid to the mairl distributor for the country of purchase It must not be sent to any other agent or distributor ex...

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