Teac A-4070G - Page 28

ERASE EFFICIENCY
Nh
LEVEL VARIATIONS
NOTE
To measure erase efficiency, a 1 kHz band pass filter must be
used.
Due to the high level of this signal, it is recommended that
only a short recording be made (approximately 30 seconds) to
prevent damage to the VU meter.
Apply a 1 kHz signal at 0 dB to the LINE IN jacks.
. Place the unit in record mode and record this signal at l5ips.
. Rewind the recording to the beginning and remove the AF oscil-
lator from the LINE IN jacks.
. Place the unit in record mode and record over this portion of
tape again.
. Rewind the tape to the starting point and connect a level meter
to the LINE OUT jack through the 1 kHz band pass filter.
Play the erased protion of the tape.
The level meter should indicate ~70 dB or less.
IMPORTANT
Using Scotch 203 test tape, recorded at the specified
level setting, during playback the output level vari-
ations should not exceed those shown in the below
chart.
7-1/2ips | 10kHz | 1.5dB or less
3-3/4ips 1dB or less