Page 1: ...INSTRUCTION BOOK for MODEL 305A PEAK RESPONDING ELECTRONIC VOLTMETER BALLANTINE LABORATORIES INC BOONTON NEW JERSEY ...
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Page 3: ...as an Ammeter 6 2 16 Measuring Above 1000 Volts Peak 7 217 Power line Effects 7 2 18 Effect of R F Line Transients 7 3 CIRCUIT DESCRIPTION 7 3 1 Input Attenu ror 7 32 Input Amplifier 7 3 3 Buffer Stage and Midsection ArrenuatOr 7 3 4 Output Amplifier 7 3 5 Peak to Peak DetectOr 7 3 6 Pulse Stretcher 8 3 7 Measuring Stage 8 38 Power Supply S 4 MAINTENANCE 8 4 1 General S 4 2 Recommended Maintenance...
Page 4: ...FUSE lA SLO BLOW PILOT LIGHT POWER SWITCH INPUT TERMINALS RANGE SElECTOR Fig 1 Ballantine Model 305A Peak Responding Electronic Voltmeter 0 Model 305A S 2 Rack Panel Mounted Version ...
Page 5: ...0 pF on 350 millivolt range anJ above 2 megohms and 25 pF below 350 mi ll ivolt range Meter Scales Logarirhmic volrage scales from 0 9 ro 3 5 and 2 S I Linear decibel scale from 0 to 10 Amplifier Characteristics Ourput Amplifier omput ava ilable at BNC conneCtor markeu OUTPUT Gain Maximum of 86 DB I DB adjusreJ in 10 DB sreps with range selector Frequency Response 5 ro 500 000 cps 2 3r if loaJi ng...
Page 6: ...ifier ro The procedure for measuring rhe peak value of a waveform Outpur Jack depends on its degree of symmerry Detector Circuit is disconnected 2 5 1 Nearly Symmetrical Waveforms with Polarity POSITIVE The ourput of the amplifier is in Positive and Negative Amplitudes in Less than a phase with the voltmeter input 1 to 2 Ratio Proceed as follows With function switch in PEAK position inStrulllenr i...
Page 7: ...rminals and rake ourput from BNC conneCtor marked OUTPUT AdjUSt range swirch for desired amplificarion wirhout dis ion Amplifier characteristics are described in 1 2 2 6 2 7 and 28 To utilize the full frequency range and shortest rise time of the amplifier rhe capacitive load ing at the omput must not exceed 10 pF and the load resistance SllOUld nut be bc low 30 000 ohms Capacirive loading of the ...
Page 8: ...s I millivolt Every subdivision is 50 microvolrs When measurement is finished rhe PEAK AD should be reser according 2 113 Q a oid errors in normal measurement 2 13 Measuring Short Pulses with Low Duty Cycles When pulses wirh durarion less rhan I microsecond or reperition rares below LOO pps are measured and when rhe duty cycle is below 0 002 a correction should be added rhe readings if the reading...
Page 9: ...e high and low frequency ends The response at the high frequency end is adjustable ro a limited amount by variable capaciror C6 The first stage rube V I is shock mounred and shielded ro reduce microphonics and hum pickup First and second stage heaters are ptr d with de Tht plare voltage of direcr coupbl stagt V2 can be adjusted wirll rhe scrc en snits resisror R 18 Neun bulb NEZ prorecrs V3 in cas...
Page 10: ...s A silicon reerifier volrage doubler circuit is used in rhe B recrifier cirOJir Three separate filamenr circuirs are used One XX for rubes in power supply one YY for amplifiers and a recrified de filament for rubes V I V2 and V5 4 MAINTENANCE 4 1 General 4 3 2 A dc volrmerer I voir ro SOO volts with 10 meg ohms inpur resistance 3 o accuracy For checks Thc insrrumenr IS designed tor an exrended pe...
Page 11: ...suitable for replacement However for highest stability mbes with approximately 50 hours of n Allow a minimum of OJ hours warmup aging under similar conditions as in the voltmeter are recommended b Check SCALE AD as described under 2 11 l c Apply accurate I volt Pcak tO Peak 0 259 to After tube replacement the Pin 7 voltage should be the voltmeter adjusted to following limits Set Range Swirch to 10...
Page 12: ...nature of the regulatOr transformer a short should become necessary to rerum the instrument or any in the filament or B circuit does not necessarily burn part thereof to Ballantine LaboratOries Inc for examination Ollt the fuse nor harm rhe power transformer or servicing at least 4 inches of packing material should be placed around all sides of the instrument to prevent damage 5 3 3 Tube Replaceme...
Page 13: ...y voltage is outside the specifi d limit the associated tube should be checked connecrions inspected and compo nents measuted until the reason for voltage Jeviation is found and correcred 5_ 5 Signal Tracing If the reason for the voltmeter malfunction cannot be found by a dc voltage check signal ttacing siloulu be used to locate tile trouble For signal tracing apply a I volt Peak to Pea k 0 5 voll...
Page 14: ...ADJUST INPUT AMPLIFIER ADJUST ADJUST OUTPUT AMPLIFIER 100 mY 400 KC SEC 5 6 ADJUST NEG RESPONSE 100 mY 400 KC SEC 5 6 PHASE INVERTER 400 KC 100mV SYMMETRY SECTION 5 6 SECTION 4 6 2 Fig 2 ...
Page 15: ...esponse has been checked or corrected The adjusrment of rhe 10 volts to 1000 volts range should be done before rhc adjusrment of J 50 milli volrs to 3 5 volrs range because the first adjusrment affecrs the second T o adjust rhe arrenuator response proceed as follows a Remove rhe Range and Polarity Swirch Knobs and Escutcheon Plan by removing four binder head screws from rhe front panel b Replace r...
Page 16: ...Fig 3 ...
Page 17: ... rransformer Tbis also does nor dam age rhe rransformer Small deviarions in B volrage from 300 to 310 volrs measured on Pin 1of Tube 9 should be correned as described under 4 7 2 If rhe B measures approximarely 250 volrs and hear er volrages 4 5 volrs rIllS a shorr circuir in Tubes 9 and 10 filament may be suspecred If rhe t B measures approximarely 150 volrs and all rubes look unJir a shorr circu...
Page 18: ...AD RIPPLE ADJ B VOLTAGE 300 TO 310 V SEC 5 9 2 Fig 4 ...
Page 19: ...V2 V5 High hum of power supply 5 9 2 Unstable indicarion Insufficient shielding in Inpur wlfJng Defecrive VII Defecri ve power supply 5 9 Inaccurate peak Misadj usred PEAK ADJ 2 11 3 measurement Defecti ve V6 Impossible to ser Tubes V12 V13 V1 4 SCALE ADJ VI 5 Resistors R70 R7 R74 H igh error in lower SCALE ADJ needs 2 11 1 parr of rhe scale adjusrment Error in NEGATIVE Defecrive ResistOr posirion...
Page 20: ...e 2431 CI5 3 12 pF Type 503 27 Erie 2535 CI6 01I F 0 100 6 me wI Type BYA6S1 Cornell Dubilier 2067 CI 7 12 I F 250 Y Type BR 1225 Cornell Dubilier 2508 CI8 6 2 pF 5 Type QC Qualiry 2248 Cl9 18 pF 500 Y 50E Type CM 15 Areo 2429 C20 7 45 pF Type 503 27 Erie 2236 C21 200 pF 500 Y 5 Type CM 15 Area 2371 C22 047 I F 200 Y Joq Type 192P Sprague 275 C23A 20 I F 300 Y Type DFP Sprague 2753 C23B 20 I F 300...
Page 21: ...ype EB 5er Alien Brad ley 1479 R21 9 000 ohms Type CPX I IS Aerovox 1479 R22 9 000 ohms Type CPX I iC i Aerovox 1071 R23 47 ohms Type EB 10 Allen Brad ley 1012 R24 750 000 ohms Type EB 5 Allen Brad ley 1258 R25 10 000 ohms T pe GB 5 f Allen Bradley 1063 R26 300 ohms Type EB 50 Allen Bradley 1201 R2 7 20 000 ohms Type HB 5 Alien BradIcy 1057 R28 1 000 ohms Type EB 5 N Alien Brad ley 1654 R29 15 000...
Page 22: ...Aerovox 270 000 ohms Type EB 5 Allcn BraJley 135 000 ohms Type CPX Y2 1 Ie Aerovox 10 000 000 ohms Type EB 10 Allen Bradley 3 900 000 ohms Type EB 59 Allen Bradley 22 000 000 ohms Type EB 10 Allen Bradley 27 000 ohms Type HB 5 Allen Bradley 27 000 ohms Type GB 10 r1 Allen Bradley 470 000 ohms Type EB 5 Allen Bradley 22 000 000 ohms Type EB 10 t Allen Bradley 22 000 000 ohms Type EB 100 Allen Bradl...
Page 23: ...ak Switch Type H Ballantine 3238 S4A B Push Button Switch Type 64500 170 Ballantine 3268 S5 ON OF Switch Type 80994H Arrow Hart H egeman 3052 Tl Power Transformer 60 cps Ballantine 3055 Tl Power Transformer 50 CpS Ballantine 3126 V I Type 5654 Tube GeneraI Elecrric 5570 V2 Type 6485 Tube Raytheon 7907 V3 Type 6AU6A Tube RCA 7907 V4 Type 6AU6A Tube RCA 5570 V5 Type 6485 Tube Raytheon 5570 V6 Type 6...
Page 24: ...ATOR V I 5H ATTENUATOR V 5 455 I v 2 483 v 6 5485 PEAK I v3 US IpOSITIV EI V4 AUS V7 SAU NEG PEAK CATHODE PULSE CATHODE l 52 DETECTOR r FOLLOWER STRETCHER 0 FOLLOWER I POLARITY I INDICATOR SWITCH 12 1 2 6ALS v I3 1 25814 14 I Z 6A lS VI 1 2 a14 L __ 3 N T O W C _ _ __ _ ______ J 60 CP5 RE ED If CAK ADJ I 100 TO 130 C2 EJ IFU SE I SU PPLY VOLTS 0 CRI 2 3 4 OFF I I I B V II OB2 BLOCK DIAGRAM MODEL 3...
Page 25: ...ill L IIOOOmY I ic f CG RIO J OOp I 45p 1500 R1 6 3lk l W C IQC R I5 130 W e R IB lO Ok I ll 6 k I j I 1 P41 il 300 311 IJ Il t1jI I Y 2 h I Rq3 1 1 Sk IW _i l H 1liO N 5 ITC H _ ______ A T TO P AK I I l _IOUTPUT I I I 1 n I o J W o o L QIT II V i 4 R65 4 Ok 548 III IS 814 R16 ICAL AO J I Sk D 1000cps SNE AVE SI G NAL iOWeE S C J lIPPl E VOW eE5 II I D C vOLTAGES 2936 ...