___tmt_ _l _ m
^CTI. 5
L TROI 5 JD
The Ele,ctonic Assembly consists of ecord Ampliie
Playback Amlifie and a Bias nd ßase Ocillao on one chassis
The iowe upply is mo.unted o_ a 5epaae chassis
Recod Amp1ifie
The Recor Amlifie consists o our 5tages; a hih-ga. in
penode pe-mp1iie for microphone and blanced bridge inuts
(V01, l2SJ73, wo triode-connected-entode ampliiers (VO,
VO, two l 2SJ7) , and constnt-current riode outu age (VO,
/6J5} ,
0ne o hree vailable input cicuits cn be elected by the
Inpu ansfer switch (qOl ), Vhen Ol is in the UBALA C D
IDG position, the inpu ansformer (TqO l3 and the inpu pe
mpliie (VOl) ae bypassed, and the signal is fed to the grid of
V02 th-rough h3 Recod Level Control (O).
Separate high requency pre-emphsis o each speed i5 po
vided by the ecod quali2ers (C. or CO7 and R4-l3) between
V4-O2 nd VO3, and the C combintion in the cahode retur-n o
VO. ßqualiion is changed b.y the quli2ation witch (O2).
The ouput of Xhe consan curent mpliie (V) is fed
to he ecod Iead hough the co.upling condense (C2}, h. e
Yoise alance. Bidge (22, R23, -R2, 25) serves to
counerbalance any leahage curent rom Cl2 o ny symmery
in the ias scillator (VO) outut, eihe o which would tend
-o magneti2e the ecord ead pemanently and eslt in n in
c.. rese o 5 to 3O db in noise level, and he intoducion of second
hrmonic dis tartion.
Vhen the Recod uton (O3) is pr'essed, he ecod elay
(Ol) is energied through contct K5O2- l o he ly _ely
(in its eegied position), K503- l o the Fast oward Relay
(demenegi2ed), nd K5O4-3 o the Rewind elay (de-enegi2ed)
The ecod elay herore cannot be energi2ed unless he
machine is in the PLA mode. .See igures l o 2, nd 3.)
- //53 5-3
To Next Page
Loading...
