Ampex-350-Operation-Maintenance 电路图 维修手册.pdf

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1、PIEX MODEL 350 L_ _ - OPERATION AND MAINTENANCE MANUAL fl i f - gt : i Si 0 L . SECTON l SPE:IFlA TIO NS The Ampex Model 350 magnetic tape recordeT is a two-speed audio recorder designed for use with standard 1/4 inch tape. Vlodel 350 is available i o coos o le, two-case poTtable, and rack-mount sty

2、les, all with either full or half ttack heads. The performance specifications and characteristics of the machine are as follows: TAPE SPEED 7-1/2 inches per second and 15 inches per second or 3-3/4 inches per second and 7-1/2 inches per second, FRE-UENCY RESPONSB Speed 15 II Response + 2 db 50 to 7,

3、 500 cycles + 2 db 40 to 10,000 cycles 4 db 30 to 15, 000 cycles + 2 db 30 to 15, 000 cycles SIGNAL-TO-N01SE RATIO Max. Record Level to Speed Unweighted Noise 3-3/4 60 db 7-1/2 Full Tlack 70 db Half Track 65 db 15 II Full Track 70 db Half Track 65 db Peak ecord Level to Unweighted Noise 50 db Full T

4、rack 60 db Half Track 55 db Full Track 60 db Half Track 55 db The peak record level ls defined as that Level at which the overall ( in put to output) total RMS harmonic distortion does not exceed 3% when measured on a 400 cycle tone. Noise is measured when erasing a signal of peak recording 350 -6/1

5、/53 l-l I Level in the absence of new signal. Thus, bias and eTase noise are included as well as playback amplifier noise, AH frequencies between SO and IS, 000 cycles are measured. FLUTT:2R AND wo:-r Speed 3- 3/4 7-1/2 L 5 Flutter and -low 3 % 25 % 2 % The flutter and wow measurements include all c

6、omponents between 0 and 300 cycles using an RMS meter calibrated to r ead the peak value of constant amplitude sine wave flutter, ?LAYING TIJi:S ;nTE NARTE 10- 1/2 IN:H R :.S.i.,3 (2,400 feet of tape) Speed 3-3/4 11 7- 1/2. 15 Half T-rack 4 hrs, 16 min. 2 hrs, 8 m in, 64 m in, :.:ull T ra ck 2 hrs,

7、C m in, 64 mlo. 3 2 min, STARTING TIM:C: Instantaneous (tape accelerates to full speed in less than 1/ 10 slcond. ) STOP:?ING T IME: When playing at the 15 inche s per second spe ed, the tape moves less than two inches after pressing the ,.;top button, PLAY BA:K T IMING ACCURACY: + . 2% or + 3. 6 se

8、conds in a thi.rty mlnute recording, REivIND TIME: Approximately one minute for the full 2,400 foot NA:RTB reel, CONTROL-S: The tape motion is conttolled by four pushbuttons: Start, Stop, Fast Forwa-rd, and Rewind, A separate Record button energizes the r ecord circuits, which will drop out when the

9、 machine is stopped. The tape speed is changed by a ifotoT Speed Switch, An Equalization Switch changes the amp- lifler equalization appropriately for the various tape speeds. A :Reel Size switch provides proper tape tension foT either the NARTB 10-1/2 inch reel Ot the RMA 5 inch and 7 inch reels .

10、1- 2 350 - 12/15/53 I l aECORD INPUT: A switch allows the recorder to accommodate either micro- phone lev-el low impedance input or to bridge a 600 ohm + 4 VU line, balanced or unbalanced, Mi.nus 80 dbm at the microphone input will produce the recom- mended record level, ?LAY BACK CUTPUT: Plus 4 VU

11、output into 600 ohms balanced OT unbalanced, Will feed a high impedance amplifier directly with approximately one volt, PLUG-IN Hi!:AD HCUSJNG: The erase, record, and playback heads are con- tained i.n a single plug-in head housing. MONITORING: Independent recoro and playback systems allow the tape

12、to be monitored whlle recording. A phone jack is provided to monitor either the record input signal befo-re or during recording, or the output signal from the playback head while recording or during playback, An A B switch. is incorp orated ln order that direct comparison can be made between the ori

13、ginal pro- gram and the -recorded program, The same switch transfers a 4 inch VU meter for level comparison and monitoring. The VU meter is also used to read bias and erase current, ?O:!ER RZCUJREMENTS: The half and full track machines require z. 7 amperes at 115 volts A. Machines are available for

14、either 50 or :.io cycle operation. DHv!ENSIONS AND ,fEIGHT: .Rack Mounted: (3tanda-rd 19 inch wide panel with commercial notching,) Tape Transport: 15-3/4 inches o rack space, weight 50 lbs , Electronic Assembly: 7 inches of rack space, weight 13 lbs, Power Supply: 3-1/ 2 inches of rack space, weigh

15、t 8 lbs , Console: Height -4C (maximum) Depth -28r 1/2 (maximum) .-:!idth 24- 1/2 ,vei.ght -168 pounds 350 -6/1/53 1- 3 I Two :ase ? ortable Tape Transport Case Height -13- 1/2 Cepth -17 -!idth -20-1/4 ./eight -:,9 ;0unds Electronic .,ssembly ,ly .:;ase (with extra s;lace or mixer or ca!:le atoraOe)

16、 Height -19 Depth -13 Jidth 21 .!eight -(less mixer) 42 pounds 350 -/1/53 l IN3TA.i.LATION 2. l MOUNTING AND lNTZRCONN:l:CTING - . -. -. -. - livf:?Cl TA NT: Befo,e opera ting the recorder, read the following sections on IN:i!A L- LA TICN and c-=:RA TION .i)o not attempt to Lengthen the head cables.

17、 Additional cable capacity will affect the frequency characteristics. A .:onsole Models: Gabinet and components ate packaged separatety, Assembly hardware ts provided, Assemble as follows: l) Install Tape Transpott in cabinet rame and secure with Coval-head screws and finishin washers. (2) Insert 2

18、springs in holes in electronics frame of cabinet (3) Install :.:.:tec- tronic Assembly, com;Jleting required plug-in connections between it and the tape ttanspo-rt, Use four knutled nuts to secure assembly to cabinet, (4) Re- move back panel of cabinet and install ,?ower :;upply on small shel. at re

19、ar .:;ecure with two round-nead screws :-tug :=ewer :.iupply Cable into lectronic Assembly, (5) :tug input, output, and AC power cables into rear of ;:lectronic Assembly and replace back panel of cabinet so that all cables run freely through the semi-circular cuts in its lower edge. IJVr:.=ORTA NT:

20、The back of the con- s ole cabinet must be spaced a t least 4 from the wall to permit proper ventilation. B, Two Case :i?ortable Models: lhe ?Ortable machine is shipped in a ready to operate condition, except for the connections of interconnecting cables, To operate the recorder lace the Mechanical

21、Assembly Case to the right of the Zlectronic Assembly Case, Unlatch and remove the top cover and open the cable access door on the left side of the Mechanical Assembly -:ase. Unlatch and remove the remove the front and rear covers on the :Slectronic Assembly .:ase. Uncoil the interconnecting cables

22、from behind the cable access door and plug them into mating receptacles at the rear of the .Slectronic Assembly, Gonnect the input, output, and A:, powei-to the rear of the :;1ectroni.c Assembly, l_ 350 -12/15/53 I C, Rack i./Iount i:i.odels: The rack mount machine should be mounted on a standard 19

23、 inch relay rack with the Mechanical Assembly above the main Electroutc Panel. The Electronic ?ower .Jupply Panel should be mounted dlrecUy above the Mechanical Assembly to eliminate the possibility of 60 cycle fteld from entering the Electronic Assembly. If two Model 350 Recorders are to be mounted

24、 on a Standard rack, the following placement is recommended (starting at the top of the rack): 1, Install a spaoer panel at the top of the rack if deeired. 2, Install below this panel the 1 ,1echanical Assembly for machine #1, 3. Install the Electronic Assembly for machine /fl. 4;. ns tall a spacer

25、panel. 5, Install the Mechanical Assembly for machine f2. 6, Install the Electronic Assembly for machine f2, 7. Install a spacer panel, 8, Install both Power Supply Panels at the bottom, (the cable on the power supply for the upper recorder will have to be extended in length, Extension cable #3814 i

26、s available for this purpose,) The numbers set off In parentheses in the followin text are refer- ence numbers that refer to the Parts List (:ection 6) and the figures In the rear of this book, 2. 2 AC PO NER: Connect the Fower Cable, Catalog #2413, from the AC Power Input Connector (J409 P) on the

27、Electronics Assembly to a source of 115 Volt AC power, IMPORTANT: This machine is available for either 50 or 6C cycle operation, The power line frequency is indicated on the serial number plate wnich ts lo- cated on the Power G upply Panel for rack mount machines, on the exterior of each case ln the

28、 portable machines, and on the back of the console cabinet. 2. 3 OUTPUT: .Refer to Figure 1 or 2. A, For Studio Line: Plus 4 vt:, 600 ohm line output, balanced or unbalanced, is a- vailable across Terminals 2 and 3 of the t.ine Out Connector, (J4041?), Pin 1 is the chassis ground, If uni,alanced out

29、put Is desired, tie either sfde of the 2-2 350 - 4/ 11/55 1 line to ground. It is necessary to supply 600 ohm termination to tllis ot1tput at all times in order to maintain correct meter calibration while recording 01 playlng back. Therefore, if the output Is not feeding a termtnuted line, or if the

30、 output Is not connected, such as on remote plckups, tho Une Gut Termination Switch, (!:404), must be switched to CN. B. For Connection to High Impedance Al!lPlifie . lQPt1 Connect pin 3 of the Line Gut Connector, (J404P), to the higt1 side of the amplifier Input. :itrap pins l and 2 of the connecto

31、r and connect to the ground side of the amplifier input. The Line Out Termination Switch (S404), must be left in the position designated ON at all times, as explained ln A above, 2. 4 lNPU T: Refer to Figures l or 2 and 5. The tollowing inputs a.re provided, Any low tmpedanc:e microphone, the nomina

32、l impedance of which le in the range of 30 to 250 ohms can be plugged in directly, Connect the microphone to pins 2 and 3 of the Input Connector, J401S), Connect cable ehteld to pin 1. Place the Input Transfer Jwttch, (5401), to the MIC position, The mlcrorophone input transformer ls strapped for th

33、e optimum step up for a 150 to 250 ohm source. In the case of microphones having 50 ohms or less impedance, 6 db additional gain can be obtnint!d by strapping the Input as shown in Figure SB. This is not usually necessary, however, and should not be done unless insufficient gain Is found to exist sh

34、ould the In- put be fed from a source impedance greater than 50 ohms. llViPOR TA NT, R402 and R403 will have to be changed to 24 ohms and R401 and R404 to 88,000 ohms to maintain a flat response on Balanced Brldg1ng when the transformer is strapped for 60 ohm source impedance. High impedance microph

35、ones are not recommended for use In this e- quipment. In geoeral, the quality obtainable from high Impedance microphones ia not satisfactory for professional work, In the event that l.t becomes neces- sary to connect a high lmpedance microphone, the Input circuit wlll have to be re-wired as shown in

36、 Figure 5A. Connect a balanced line to p!ns 2 and 3 of the Input Connector , (J401S) . Pin l is ground. Place the Input Transfer Switch, (3401), in the BALANCED 350 -4/11/55 BRIDGE; position, Input levels of minus 10 to plus 10 VU can be accommo- dated, The load placed on the line is approxi11ately

37、300, ooo ohms. For brldglng higher or lower level lines, an 1;1xternal brid2e can be wired in the line lo the machine. This would consist of two resistors, the value of which should be from 15, 000 to 30,000 times the RMS program volt- age, tn series with each side of the line. A 24 ohm 5% r1;1si.st

38、or should ter- minate each leg of the output side of the two bridging resistors, The junction or the two 24 ohm resistors should go to chassis ground. The output of the bridge must be fed to the microphone input of the recorder. The Input of the recorder may be connected for any impedance from 50 to

39、 250 ohms, C, Bric!.siJll an Unbalanced Source: Connect an unbalanced line, radio tuner, etc, , to pins 1 llnd 3 of the Input Connector (J401S, Pin 1 ls the ground side, ?lace the Input Transfer :3witch, (5401), in the UNBALANCED BRIDGZ position, This connection pro- vides a 60,000 ohm bridging inpu

40、t for any R.(C proram vol tagt connc-ctcd, the 1)t,ny Plug (l?502P, supplied with the machine, must be plu$!1;ed into J502G. 350 -4/11/55 2. 7 60 :Y:L:J: AM?LI:TI:SR: (:?or Drive Motor Fower) l. .Che Ampex Model 37!3 :?recisio,1 :0 cycle amr,lifier or hfodel 3GlA Speed Lock Zquipment can be plugced

41、in directly at J503,:;. Jo other con- 1,ections a.re necessary. If either of these units is used with the ,ecorcler, the :ontrol :ircuits Fuse (F402) ,.1ust be increasecl to! Amperes, uo not remove the Dummy Ph.ig (?503 P )unless one of these units is to be connected, 2. Q A.:z.:3 1C, :Oi!GCL -:A3l.

42、MZT: ,TARNlNG: Before opening the console or (,ottable cases, disconnect AC-power. :omplete accessibility or inspection or service is novided to he top and bottom of the :lectronic Assembly and bottom of the Mechanical Assembly, Gee Figure l 6 for an illustration of the :onsole :abint o,ened for ful

43、l accessibility. 1. .!emove the four ca:, nuts Gecuring the :Llectronic Assembly to the :abinet. 2. :?ull the Zlectronic Assembly u, unti.l the runners are free of the slots. einsert the runners in the short slots immediately in front of the two lower studs. 3. Remove the two set screws holding the

44、chassis 1lotto:.1 plate. The bottom plate hinges separate at the rear Hit is desired to remove the plate completely. 4. lhe frame on which the Mechanical Assem1:ly is mounted can be raised 90 degrees ot more, and held in place by a slide bolt on the lower left mderside of the frame, 5. The Powel .Su

45、pply is acceosible through the rear of the console when the slidincr panel is removecl. 2, 9 A:EGS T UND:.R:;IDJ1: ClT 1vl:S:EANI:AL ASSll:ivJEL-Y lN T .!: :;A.:;:s POrlTAB.Lli: ,.;tand Mechanical Assembly :ase on end as shown in ):igure 17. elease the latches holding the center divisions of case. C

46、pen to ap:,roxi- r,1ately c;o, Care must be taken to ins1.n-e that cables can pass through cable compartment into the main cabine, freely. 2. !C CVZi:lALL :?:i:Rl-O:U1:ANC:.,; :r:.r:.:;K: (ead .iection 3 on C,:F:.:.:RA 1I:.t before n1aking these checks.) 350 -12/15/53 2-5 I The following procedure i

47、s recommended for checking the performance of this recorder at the time of installation and as neccssarytherca!ter, A , Overall Frequency Response: - Thread a new reel of tape on the machine. :qualiz.ation cu1ves for the Record and Playback Am pli.flers are shown in Figures 6 and 7, Zntirely satisfa

48、ctory results can be obtained from any professional Gt:ality tape. l, 3-3/4 and 7-1/2 Inch Response - DUE TO THE NATURZ OF THE PRE-EMPHASIS IN THE RZCO.RD :.:IRCUIT, TAPE SATURATION :TILL OCCUR AT THE HIGH FR:EQUZNCIES UNLESS THE RESPONSE yHECK IS .MADi: AT LEAST 20 OB BELO,.r NORMAL OPERATING Li:VC:L, Therefore, check the tespons c with a sensitive meter such as a Hewlett-Packatd 400C connected to the output, In absence of a sensitive meter, a standard VU Meter pre- ceded by a flat amplifier with at least 20 db gain can be used, Response will be within the limits indicated in th