Erase head (15B) should be so positioned that its
face ia parallel with the holes in mounting bracket (15C)
andparallel to the tape. The vertical height of the head
should be 0.584", measured from the mounting bra-
cket to the top of tle erase head gap. If the head is too
high, the recording may not be erased completely; if
the head is too low, part of the lower track may be
erased.
Record-Playback Head
l. Threadastandardfrequency tape (RCA 12-5-
61T or equivalent) on the tape recorder. Con-
nect output meter acrosg left-channel speaker
lead terminals.
2. Record-playbackhead(i5A) shouldbe so pos-
itionedthatthe front of the head is parallel
to the edge of mountlng bracket (l5C).
3. Adjust right-hand tape guide post (18) for
maximum output while playlngthe 1,000-cycle
portion of the tape. Adjust left-hand tape
gutde post (18) so that the tape is approximate -
lylevel across front of head. Repeat right-
hand tape guide post (18) adjustment.
4. AdJust right-handhead mounting screw (15R)
for maximum output. Left-hand head mount-
ing screw (l5L) must be tight.
Recording Level I ndicator
Recording level settings are obtained by two neon
bulbs, Type NE-51. .Adjustment of tlrese bulbs are
necessaryonlywhenthe bulbs or components in these
circuitsarereplaced. Thefiringlevelon the record-
ing indicator is adjusted by means of two adjustable
controls (R3) and (R4). The controls are accessible
aJter tlte cabinet bottom cover 1g removed.
To adjust firing level of recording indicators,
the mechanism must be in the cabinet. Refer to
Fig. 3 for location of adjustments.
l. Connectan audio signal generator to the ra-
dio-Phono jack. Set generator frequencyto
approximately l, 000 cycles.
2. Connect a VTVM to teet point TP-3.
3. Depress Monitor push button.
4. Ground test point TP-I. Adjust generator
output and,/or tape recorderLoudness con-
trolto provide approximately 2. 3 volts rms
reading on the VTVM.
ELECTR ICAL ADJU STMENTS
5. Bemove ground from test point TP-l and ad-
justNormal lndicator control (Ra) by turning
counterclockwise and then clockwise until
the Normal neon bulb barely lights.
6. Ground test point TP-I. Adjust generator
output andr/ or tape recorder Loudness control
toprovide approximately 6. 8 volts rms read-
ing on the VTVM.
7. Remove ground from test point TP-l andad-
just Overload indicator control (R3) byturn-
ing counterclockwise and tlen clockwise
until the Overload neon bulb barely lights.
Gain Control
Gain control (R5) enablesthe volume levelof the
external speakers to be equallzed with the volume level
of the internal speakers.
To set the gain control:
1. Thread a standard frequency tape on the re-
corder.
2. Connectanoutputmeter across the terminalg
of the left channel speaker contained in the
recorder.
3. Turn on recorder and allow to warm up for
geveral minutes. Set volume control at nor-
mal playrng position. Set switch (M9) to
Stereo-Single.
4. Depress the Stereo and Play push buttons
and, while playing the 1,000-cyclepartof the
tape, note the output meter reading.
5. Depress Stop bar and reverse tape reels to
turn tape upside down.
6. Disconnect the output meter from the re-
corder and connect to the terminal of right
channel speaker contained in the companion
speaker unit.
7. Depress the Stereo and Play push buttons
and, while playing the l,000-cycle part of
the tape, note the output meter reading.
8. Adjust gain control (Rb) to obtain the same
indicatlon on the output meter as $/as noted
in Step ?. For locationofgaincontrol, refer
to Fig. B.
t/r-
P'3
,.6 <
u!a
-lJ
PO
a-
A=
ro
PH
UIF
LUI
$F
--6
la
ata
dt"
\@
TT
o
a-
(D
l\t
TP-I^
osc (D
,?0, tl'i3o
TP - 3Ci)
AUD IO-
OVER-LOAD NORMAL
ee
RECORDING
INDICATOR
A RIGHT CHAN.
- GAtN EQUALtzER
FIG. 3 AMPLIFIER ADJUSTMENTS
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