Summary of Contents for BTE-10B

Page 1: ...r ceramic 5 µµf Capacitor ceramic 2 200 µµf Capacitor ceramic 10 µµf Crystal diode 1N34A Lamp neon Fuse 0 5 amp Mount shock mount 5 minimum quantity shipped RECOMMENDED SPARE PARTS Symbol Cl06 Cll 3 Cll4 Cll5 Cl22 C l24 Cl26 Cl30 C l32 C l35 Cl38 Cl40 Cl45 Cl52 Cl53 Cl57 Ct69 Cl 72 Cl80 Ct84 C209 C211 C212 CI07 Cl20 Cl27 Cl29 Cl31 C t34 Cl43 Cl44 C l46 Ct47 Ct50 Ct66 Cl 33 Cl55 Cl56 C l48 C214 Cl7...

Page 2: ...www SteamPoweredRadio Com E 2 0 e 11 0 FIHAI Mo IP c T IMllilt 0 92203 Figure E 1 BTE 108 FM Multiplex Exciter ...

Page 3: ... all harmonics up to 30 kc s and is measured following a standard 75 µs de emphasis network Subcarrier modulation percentage can be brought to 50 if required See Subcarrier Modulation in text 240 208 or 117 V single phase 50 60 cps 5 300 wa11s Approx I 17 volts 50 60 cps IO walls each 7500 ft max 20 C to 45 C Height 24 80 lbs Width 19 Depth 11 Referen e shall be 7 5 kc s deviation of the suhcarrie...

Page 4: ...n be made during operation without disturbing the AFC circuit in any way This type display requires no synchronization or other adjustments Power supplies employ semiconductor rectifiers The high voltage regulated supply which furnishes d c plate and screen voltage utilizes a bridge type germanium rectifier Modulator and oscillator fila ments are supplied by a d c supply employing a full wave sili...

Page 5: ... 107 0602 73 102 5 118 6343 24 92 7 107 2917 74 102 7 118 8657 25 92 9 107 5231 75 102 9 119 0972 26 93 1 107 7546 76 103 1 119 3287 27 93 3 107 9861 77 103 3 119 5602 28 93 5 108 2176 78 103 5 119 7917 29 93 7 108 4491 79 103 7 120 0231 30 93 9 108 6806 80 103 9 120 2546 31 94 1 108 9120 81 104 1 120 4861 32 94 3 109 1435 82 104 3 120 7176 33 94 5 109 3750 83 104 5 120 9491 34 94 7 109 6065 84 10...

Page 6: ...3 VDC I 6 3 VAC I L _ _J I I I I _J Figure E 2 Block Diagram BTE 1 OB FM Exciter with very low harmonic distortion Each tube is almost a pure reactance and loading of the oscillator is greatly reduced providing better AFC action Moreover the pushpull modulator automatically balances out temperature and supply voltage changes Modulating circuits are very effectively decoupled thus minimizing the po...

Page 7: ...quency and simul taneously provides a safeguard against uncontrolled and possible off frequency operation Circuits of the AFC system are diagrammed in Figure 2 A small r f voltage is fed from the master oscillator circuit to the divider chain where it is divided by 240 to a range of 20 to 25 kc It should be noted that at the same time deviation due to modulation is reduced from a maximum of 5 kc t...

Page 8: ...age by the capacitors C 188 and C189 and the choke L 108 The network consisting of capacitors 104 187 CI 98 and resistor R 168 extends the control range of the phase detector beyond the 90 degree phase difference limit that would otherwise be imposed by feeding a small amount of the beat frequency back to the reactance tube grid This beat frequency then causes the master oscillator frequency to sw...

Page 9: ...cally decreases until it is zero The system is then locked in and the d c voltage maintains that condition I I I l 100 i 0 V I l 50 b E 9 Off Frequency Detector Protection against loss of control by the automatic frequency control system and possible off frequency operation is provided by the off frequency detector circuit shown in Figure 6 VI 15 is a 6AS6 mixer stage which is fed from the last di...

Page 10: ...from either 120 volt or 240 volt single phase a c lines The equipment is shipped with the taps set for 240 volt use The crystal heaters 11111st b1 rnllllffled 011ly to a 120 t olt a c source Particular care must be taken to insure that proper connections are made before power is applied to the equipment Reference should be made co the overall schematic diagram and to the table Tramfor111er Primary...

Page 11: ...acio 6 Turn CRO Switch to 2ND DIV position and adjust T105 for a stationary Lissajous figure anq a division ratio of 1 4 Figure 7 c E 11 7 Turn CRO Switch to 3RD DIV position and adjust T 06 for a stationary Lissajous figure and a division ratio of 1 4 Figure 7 d 8 Turn CRO Switch to 4TH DIV position and adjust TI 07 for stationary Lissajous figure and a division ratio of 1 5 Adjust TI08 for maxim...

Page 12: ... the range Turn screw back half the number of revolutions counted Repeat this for TI05 Tl06 TI07 and TIIS 14 Tune L105 to maximum indication of meter meter switch in le V107 position NOTE Remove C214 for center frequencies above 100 me 15 Tune Cl37 PLATE TUNING to dip on meter meter switch in Ik V107 or better in II Vl07 position Adjust Cl39 OUTPUT TUNING to obtain proper grid current in following...

Page 13: ...Y Rl85 as much as possible to prevent CRT burn in 20 Multiplex Operation Best crosstalk will be obtained with all multiplier and amplifier stages tuned for maximum grid current in the following stage or for maximum power OPERATION In daily operation of the equipment the crystal heaters should be left on continuously Then after application of power to the exciter and allowing a short warm up period...

Page 14: ... produce the required deviation As indicated on the chart the higher subcarrier frequencies require slightly more voitage than the lower frequencies To obtain a 10 kc deviation of the main carrier at 67 kc 3 6 volts should be selected At a 32 5 kc 2 6 volts will produce the same main channel deviation The above method is approximate and subject to tolerances in the order of 25 percent It is recom ...

Page 15: ...h the automatic frequency control fail The operator will be warned of the loss of control by loss of carrier or by the erratic performance of the carrier frequency monitor Tube or component failure can be found in some cases by switching the meter switch S102 through each of its positions until an abnormal reading is found identifying the difficulty The oscilloscope switch S106 may also be helpful...

Page 16: ...10 10 Vl07 E0 Doubler PA 62 62 Vl07 I Doubler PA 49 48 POWER OUTPUT PA see text I TYPICAL TUBE SOCKET VOLTAGES BTE 1 OB FM Exciter Tube Symbol Type 1 2 3 4 VIOi 6AQ5 2 15 5 0 6 4 v102 6AQ5 O 15 5 0 6 4 V103 6AQ5 17 0 0 6 4 VI04 6CL6 7 6 0 150 0 Vl05 5763 320 10 0 Vl06 5763 320 10 0 V107 6146 48 6 3AC 225 48 v1os 6AH6 4 5 75 0 6 3AC VI09 6AH6 s 90 0 6 3AC Vll0 6AH6 13 95 0 6 3AC Vlll 6AH6 7 100 0 6...

Page 17: ...recommended in the Trouble Shooting Equipment Chart If the volt age across RI 16 is very small the tube is not oscillating and another rube should be tried Next measure the r f voltage across pins A and D of coil Tl03 Approximately 2 V rms should be pres ent Use VTVM with RF probe Tune Cl05 for a peak reading on MIOI with the selector switch in the VIOi and V102 11 position When peaked 7 V rms r f...

Page 18: ...plus or minus AFC position If the final frequency the assigned frequency of the station is off center by 4320 cps Meter MlOl will swing from maximum positive to maximum negative and return to maxi mum positive indication in I second The meter should show a m iximum reading of 80 on ics dial representing 8 volts at the junction of L108 and Rl68 If less than 8 volts is obtained c heck the AC voltage...

Page 19: ... To check quickly whether VlOl and Vl02 are properly modulating the carrier feed a IO db sig E 19 nal at 30 cps to 101 This will produce 2 45 volts across J10l 62 vol ts from pins 5 to 3 at XZ101 08 volts from terminal 6 to 15 of Tl0l and 245 vol ts from terminal 4 to 14 or 10 to 13 of T 101 This modulation should cause very noticeable broad ening of the circle on the CRT in the PHASE DET position...

Page 20: ...5 VIIO TlO6 LIO5 VIII VIO6 TIO7 Tll4 VlO7 Cl37 Cl39 LIO9 C2O0 TIO4 TIOI ZIOI Rl85 Vll8 SIOI Rl83 Figure E 11 BTE 1 OB FM Exciter Front View 92203 YIOI LlO8 YIO2 Vll7 SlO5 SIO6 Vll2 Lll2 Rl74 Vll5 Tl II Tll5 Vll5 TIIO C202 TIO9 Vll6 Vll4 TIO8 MIOI LIii SIO2 C2OI SIO4 SIO3 Tll3 LIIO ...

Page 21: ...www SteamPoweredRadio Com XDSI02 XDSIOI XFl02 XFIOI S 101 XZIOI TIO Till TBI T 113 L 110 JIOI T l 14 L 109 Figure E 12 BTE 108 FM Exciter Rear View Tl04 XVl08 E 21 JJ02 Jt06 ...

Page 22: ...www SteamPoweredRadio Com E 22 Cl43 Figure E 13 BTE 108 FM Exciter Rear View Cl35 Cl32 Cl45 C136 Cl40 Cl27 Cl44 Cl31 Cl34 ...

Page 23: ... CRIOI CIOI Cl02 RIOI Rl02 RI03 RI04 CRl02 Rl70 C 189 RIOS RI06 Rl07 RIIO Rl75 RI09 RIii RIOS Rl41 Rl43 Rl49 RI 15 Rl44 R 117 RI 18 R l2I Rl20 RI 19 R 122 c 1 R123 Rl24 Rl25 Rl98 Rl97 Rl95 Rl96 Rl33 Rl29 R l3 2 R 130 Rl46 R 136 Rl48 Rl47 Figure E 14 BTE 108 FM Exciter Rear View E 23 ...

Page 24: ...www SteamPoweredRadio Com E 24 a EARLY PRODUCTION MODELS ONLY FOR REPLACEMENT ORDER PLATE CAP CONNECTOR STOCK NUMBER 219742 b Figure E 15 View of PA and Oscilloscope Subassemblies ...

Page 25: ... 6 140 µµf fixed ceramic 01 µf O 100 500 v feed thru 001 µf 500 v fixed ceramic 01 µf 0 100 500 v fixed ceramic 10 µµf 1 µµf 500 v fixed ceramic 68 µµf 2 5 500 v fixed mica 820 µµf 10 300 v fixed ceramic 01 µf 0 100 500 v fixed paper 1 µf 10 100 v fixed mica 220 µµf 10 500 v fixed ceramic 001 µf 0 100 600 v fixed ceramic 18 µµf 10 500 v feed thru 001 µ1 500 v fixed mica 220 µµf 10 500 v fixed cera...

Page 26: ... 1 476473 1 728446 18 477920 2 48 1799 1 427992 1 890599 1 1 Description fixed ceramic 01 µ 0 1 00 500 v fi xed paper 1 µ 20 400 v fixed ceramic 47 µ µ 5 500 v fixed paper 1 µ f 20 400 v fixed mica 330 µ µ f 5 500 v fixed ceramic 10 µ µ 1 µ µ f 500 v fixed mica 82 µ µ 10 500 v fixed paper 33 µ f 20 400 v fixed ceramic 01 µ 0 100 500 v fixed mi ca 680 µ µ f 5 300 v fixed mica 1100 µ µ f 5 300 v fix...

Page 27: ... 458572 97 82283 50 82283 86 82283 59 82283 50 8228 3 86 Description Connector female Connector female Connector coaxial male RESISTORS fixed Composition unies s otherwise specified 180 ohms w 330 ohms 5 w 180 ohms 5 w 82 ohms 5 w 15 000 ohms 10 w 2200 ohms 10 w 15 000 ohms 10 w 2700 ohms 10 w 1200 ohms 10 1 w 330 ohms 5 w 18 000 ohms 10 w 100 000 ohms 10 1 w 33 000 ohms 10 w 27 000 ohms 10 w 10 0...

Page 28: ...6 15 99390 3 8856946 2 99088 2 737867 18 737870 18 99390 1 737867 18 737870 18 737867 18 99390 1 8944202 1 746002 7 746048 1 481755 3 8815313 9 Description 1 megohm 10 w 10 000 ohms 5 w 220 000 ohms 10 w 100 000 ohms 10 w varibale carbon 2500 ohms 10 2 w 330 000 ohms 10 w 47 000 ohms 10 w wire wound 2000 ohms 3 25 w 47 000 ohms 10 w 330 000 ohms 10 w 22 000 ohms 10 w 39 000 ohms 10 1 w 820 ohms 10...

Page 29: ... l lg 3007 5 737820 507 Knob l dia for Sl0S 215877 737820 505 Knob 1 1 2 dia for Sl02 and Sl06 213996 69916 10 Knob 3 4 dia for RISS 57692 8896313 1 Mount shock mount 217574 483884 9 Shield tube 7 pin for 6AQS 215853 483884 12 Shield tube 9 pin for 6CL6 5763 53016 99369 1 Shield tube 7 pin for 6AS6 54521 99369 2 Shi el d tube 7 pin for 6AU6 563 59 8888549 2 Shield tube 9 pin for 12AT7 ...

Page 30: ...www SteamPoweredRadio Com E 30 NOTES ...

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