Ampex-300-Service-Bulletins-1953 电路图 维修手册.pdf
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1、JPIEX CORPORATION . 93-4 CHARTER ST. EMERSON 8171 TWX REDWOOD CIJY CAl 41 CAILE AO DRESS, AMP EK, REDWOOD CITY R E D W O O D C I TY, C: A l I F O R N I A MAGNETIC RECORDERS l)Alf, MOCH, IUllET1N NO, ,i,0 NO, SERVICE BULLETIN 20 March 1953 300 2 l 1. Erase Auatmenta For proper erase current the erase
2、 trimmer is adjusted to provideOO tom m. a. instead or the 2.50 m. a. originally stated in the Instruction Book. Actually, 160 m. a. will erase peak recording level with.ill specificatiorus. In checking erase, alway-a check with both record and erase heads connected, as the bias on the record head p
3、rovides part ot the erase. ,. I JPIEX CORPORATION 934 CHARTER ST. EMERSON 8-171 FWt. REDWOOD Cl1Y CAl 41 CABLE ADDRESS, AMPJL REDWOOD CITY RE DWOOO CITY, CA LI FOR NIA DAU:. MOOEI, IUlLH1H HO, ,._GE NO, SERVICE BULLETIN 2J :.:i:-c 195) soo 3 . 1. Reels. It haa been found in aoma isolated caaee that
4、wen the tape is allond to run all tha Wily out at the end of a fast wind a aeotion over a toot long will ba broken ott the end. Upon investigation. this was found to be due to the aharp edges on the alot opening ot the reel hub through which the ta.pa ia threaded. The sharp edges appaNntl;y provided
5、 high Motion and did not allow the end ot the tape to lID. out .freely. When these sharp edge11 were filed ott. the b.,ak:age no longer oooulted. Thia intorma.tion is being fon111.:rded to the NARTB Sub-Comittee tor the standys be placed on both tunrtablee. In using the small RA 7 inch reels. abno11
6、1l8.l hold- llaok ten1ion1 will ooour at the end f the reel d to the Blllllll hub diameter. This may oause trouble due to slippage at the capetu idler (see item No. 8 below). It the small type reels are to be used ezolusively, resistors R401 and R403. in seriee with the Rewind and Takeup 1110tors re
7、spectively. should be inoreased to the 111U:innun aetting. See Senioe l!ulletin Oto add switch for-both 7 and 10-1/2 reel1. It is Noomme:aded that the smaller s reels not be used for recording or playbaak. (To play the s reels,. erlarnal resiston would have to be added to R401 and R40! tor proper te
8、nsions.) 2. Thread!. In threading the tape1 be sure to remove any adhfll11lvi. that may-have been usad toaeal the end. It this adheaiT 111 not removed the first layer 1118.Y stick and oausa the end to bleak ott at the end of Rewind. I - MIIPIEX, : C OR PO RAT l ON I 1lol (ITV (Al ,1 0:At, f A(:(:l!H
9、 .VolllflC. f ,vOOO (lh l?EOv,OC : C ,.Ca.I OR.,.,., SERVl(E BULLETIN MA(;r,_TJ(: R.F.(.ORDr-.R:. .,.,. 20 lla. bu1t111C ot tho olello14 .td oll. O,.fttft i. oa,et:t tbo.ll 110 -tho oi.td lo a-t.4, the -ot polm: ot ti. .,_,. on mi tho ilfkn:ttwt1.,.11 Nd11ot111 tlla - ara 7 a oon14erabl - ODd tho,.t
10、o,. -.v, .ii ,.tt,. to . to 11 tt.d I) tho oolao14, !la 11111PD21M or -.at.11111 aw. -.i. I llolow 110 ,. ol.J n,.,i,. dl-4 oad St t, ,otlbJ. tlla41 -II.tao 1-Te ,_ obSpp-4 la 11101!. .,Ill., . -e. MU ,l:o T AI-J o we. C.C.-.P:.A.T-E:.O. I - SERVICE BULLETIN C ORPO RATION 93 CHARTER ST. EMERSON 8-14
11、71 TWI( REDWOOD CITY CAl I CA9LE ADDRESS: A MP E . RE DWOOO CIT t , E D W O O D C I T Y, C A L I f O R lI I A ll)I)JL SOO COISOLB CABillllI OAU, MODEi, IUUITIN HO, PAG! NO, 20 March 19.3 300 6 l l. The toU teat ot the oonaole aabiut an adjua-table, 10 tbat the oabinet -.,. be lneled on =: :10:-i it
12、bcco?:es wam. The excess oil ;resent cliabs up the capstan when the n;ichine is o-e:rated. Jrrlinaril:v, thiG oil is caught by the felt raser on to, of the be:i.ri. :ig housing. (!he necl:-re:-ie ,7as1er shami in fig. 2 of t1-ie instruction book 1,aa eli!.li.nated in : rori.1ction because it prod.:c
13、e:i f1;tter.) If this Tasher !eCOl!leS saturated 11i t.h oil, lhich usuaily happens, then it 1nll !lo lonF,er behave an an effective sea.l. Therefore after the first ,;eek or so of operation, nhen !lost of the excess oil has had a chance to :1:irl: ,t, te felt wa3her should be removori and ,ashed ou
14、t in carbon tetracl:)ride. Siply remove the capstan dust cap (see fig. 2, instruction bJok) i;o reno1e tc felt -;,:asher. If txis ,rasher is l:ept reasonably dry, then no troul-ile should be experienced ri th oil creeping up t?le capstan. I - l PEX 1 CORPORATION -. - _ _J 3 CHARTER ST. eesoN a-1,11
15、rwx lfOWOOI) CITY CAL 41 CAB LE DOR ESS: AMP EX, REDWOOD CITV R E D W O O D C I T Y, C A l I F O R N I A 0411!: MODEL: IUlUTIN NO: SERVICE BULLETIN 20 March 195.3 JOO 8 2 L._-!E:MOVE:. t:APSTA.t-J OU.ST COVER S. -FE:.LT 1,./ASE:.R A.S GOWW POSlTlOJ Ct-.PST.J ASSE:J. So T-A.T CE.1-,fie:R LNE. BE.TVE:
16、E. BOT4 l-0.E.S l$ VElitTIC.A. wrr L RGE. C OLE. 0 Tl- E BOTTOM AS S CW-.!. I C.A.P$TA.t-.l ;il-lOULD NEED PO$TOtJll.1G $E E 6 vc. a,J. 4 TA.P lc.-3.2. .l, C:. I L,._!iGaE: C.SK. .-40LE. I ScQT 6-3 )(. Y4 L:. i=LA. T -1.D. MA.C lt.lE. SCR-E.W, I PEX CO RPO RATION 934 CHARTE!I ST. EMERSON 8-1,71 TWX
17、RfOWOOO crrr CAL CA8LE AOORESS, AMPEX. REDWOOD CITY R E D WO O D C I TV, C AL I F O R N I A MAGNETIC 11.ECOROE.RS DAff: ,.ODEl, IULlETIH NO, PAGE NO, SERVICE BULLETIN 20 t!a:-ch 1953 300 9 l 1. eter in-out and terminals the line: Control Panel. !he r:eter Control anel was designed for balanced outpu
18、t. If i.t is desired to operate unh1:anced, the following on the 1:eter Control Panel should be used as tho r.ro1.:.:-.ded side of :o. 2 on the Line In co:,nections. No. 1 on the onitor co:mections. No. 15 on the Line Out connections. I CORPORATION 9J4 CHARTER ST. EMERSON S-1471 TWX REDWOOD CITY CAL
19、 - CITY. CALI FO NI A MAGNETIC RECORDERS DAT!: MODEi., ltlll!TII NO, PAC NO, SERVICE BULLETIN 2 );.3.rch 19S3 JJO l. Tape Slippage. Various u3crs have reporte,i th c -+JE) :-eel when1 the hold-back tP.nsi o:n is r:.rhc st. :he co.lii tio.l ! ; it:-ter exagp:er- ate:! if a sall P.TI.A: type ree 1 is
20、i.:sed in .-hich :ase t:he !:.ll-:-J:.1ck .e:-,sio:i is even hiP-her. :!:!fee ti ve capr,ta.n idler d!i 11!1f. f :i:-ce is :-euce,1 1S t1r: .: ip:.-1:-: idler r,radually pi:ks up t:le lubr-caton with ,vhic:1 l.inr:e:;:itsi tion. :-:e i,iler p:-essu,e s:-i:)1,1:i :,e s 1.1fficient to just :ief:irn. t
21、he tape. The rress:.re can hfi i :-i-,:;cc as de- scribed n t:ic instruc.ion b?ok. Care :nust .)e taker. r,o :!.:il Y:-loading the capstan idler soleoid if aurli ,le hu:n is to he aso-:. ie. S:ic; h: r.as no ef!ect on t:,e perf:ire.a:-ice of the re-or-ler. I PIEX -,.-t-.M I G N E T I C R E CO R D I!
22、 R S C OR PO RAT I O N 93 CHARTER ST. EMERSON 8-1,71 TWl( RfOWOOD CITY CAL 41 CAILE ACCESS: AMPEX, RE OWOOC CITV R E D W O O I) C I T Y, C !. L I F O R N I A OATIE MOOEl: uLLETIN NO, .iGE NO SERVICE BULLETIN 20 liarch 1953 30:J 11 l l. Bias Ad ustment. As stated in the ins:.r.1ction book, paragraph
23、4, p.2, section , tie bas is set at a current at which the overall output at 1000 CY(:les is 2 db below the axirnlllll. For serial numbers above 1605 see Service Bulletin #19 paragraph B. T!le bias curre!lt is Yer-y .lncri tial as far as affecting distortion, once a certain minimum is exceeded. Abov
24、e this minimmr. point, the output remains constant for the. same pistortion over a very IVide range. e only effect of excessive bias current is to erase high frequencies, Actually, the optimum current for the bias setting is that which pr:duces maximum sensitivity at 1000 cycles, The bias setting is
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