Teac A-2300SR - Overall Performance Checks and Adjustments; Overall Signal-to-Noise Ratio; Optimum Erasure Measurement; Channel Separation Check

8-19 SIGNAL-TO-NOISE RATIO —OVERALL—
Using blank Test Tape ........... YTT-8013
1.
2.
3
Output and Line controls should be at the specified posi-
tions.
Remove the AF oscillator from the LINE IN L, R jacks.
Place the deck in the Record mode with “no signal”
applied. Note the point on the index counter where re-
cording begins.
. Rewind the tape to the beginning point and play it back.
. The noise level as indicated on the VTVM should be
readings listed below.
... HIGH (7-1/2 ips)
... LOW (3-3/4 ips)
~55 dB, or more
—53 dB, or more
NOTE: This —55 dB/—53 dB corresponds to the Signal-to-
Noise Ratio of 47 dB/45 dB (minimum): the dif-
ference between residual noise of —55 dB/—53
dB and specified output level —8 dB.
NOTE: Since this measurement method and the measure-
ment methods used to obtain the catalog and
owner’s manual S/N spec, are different, the values
here and in the catalog and Owner’s manual will
be different.
8-20 OPTIMUM ERASURE MEASUREMENT
Tape SPEEDSW.......... HIGH
3 Thread the TEAC YTT-8013 Test Tape on the deck.
2. Apply a 1 kHz signal at 10 dB above the operating level
of —8 dB (308 mV) to the LINE IN jack.
. Make a 30 second recording of the above signal while
reading and noting the level of output, then rewind to
beginning of this recording.
. Disconnect the 1 kHz signal source (AF oscillator) from
the LINE IN jack.
. Connect a VIVM to the OUTPUT jack, through a 1 kHz
Narrow Band Pass Filter.
. Put deck in the Record mode and “record” (erase) over
this previous recording, then rewind to beginning again.
. Put deck in Play mode and monitor the output on the
VTVM.
. Difference in output level, between the 1 kHz signal and
the “no signal” section level should be more than 68 dB,
NOTE: Filter loss should be considered.
20
8-21 CHANNEL SEPARATION
1. Be sure tape is completely bulk erased prior to doing
these checks.
2. Apply a 1 kHz signal at —8 dB (308 mV) to L chan.
3. Place deck in Record mode.
4. While recording, measure the OUTPUT on R chan with
VTVM connected through a 1 kHz Band Pass Filter.
Spec. should be 50 dB.
OSCILLOSCOPE
DECK
under TEST
LUNE IN
ra)
“shies IkHz FILTER
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T-39m
Fig. 8-12 Test Connections for Channel separation check
8-22 TRACK-TO-TRACK CROSS TALK
REJECTION
Following is the measurement procedure at 7-1/2 ips using
the TEAC standard tape, Type YTT-8013:
1. Thread the TEAC YTT-8013 Test Tape on the deck.
2. Apply a 125 Hz signal at —8 dB to the righi channel
LINE IN jack.
3. Make a 30 second recording of the 125 Hz signd.
4. Interchange the left and right reels and rethreal tape on
the deck.
5. Connect a VTVM to the right channel OUTPUT jack.
6. Playback the recorded signal portion of tape and moni-
tor the level on the VIVM.
7. Spec. should be 40 dB or better.
8-23 DISTORTION CHECK
Tape SPEED .......... 7-1/2 ips
BIAS and EQSW ............ 1
1. Thread the TEAC YTT-8013 Test Tape on the wit.
2. With Line and Output Controls at Operating (pecified)
Level, apply a 1 kHz signal to LINE IN jacks, atO VU.
3. Place the deck in the record mode for about 10seconds.
Rewind and play this recorded section of the taje -
4. Read the indicated value on the distortion analyze r.
5. The distortion factor should be 1.0% or less.