Panasonic RS-612US-D - Frequency Response Charts and Measurement

Overall frequency response
Equipment:
* VTVM
+ AF oscillator
+ ATT
* Test tape
(reference blank tape)
«+-C-RA for Normal
+++ C-RF for CrOz
MEASUREMENT & ADJUSTMENT
5. When the distortion factor does not satisfy the standard, check the
bias current. When the bias current is lower than standard, distor-
tion will increase.
Care should be exercised in the adjustment because the bias current
also has an influence on the overall frequency response. Refer to
“The overall frequency response” and “The bias current adjustment”.
Standard Value: Less than 2.2% (Normal)
Less than 3.2% (CrO2)
Note:
Before measuring, and adjusting, make sure of the playback frequency
response (For the method of measurement, please refer to the playback
frequency response).
1. Test equipment connection is shown in fig. 15.
2. Load reference blank test tape and place UNIT into record mode.
3. Supply 1kHz signal from AF oscillator through ATT to LINE IN.
4. Adjust ATT so that input level is —20dB below standard recording
level (standard recording level =0 VU).
. At this time, LINE OUT level indicates 0.042 V.
. Record each frequency 50Hz, 120Hz, 560Hz, 1kHz, 2kHz, 3kHz,
10kHz and 11kHz (12kHz for CrOz tape) at the same level.
. Playback and express in dB the difference between playback output
level of each frequency based on playback output level of 1 kHz.
. Make sure that the measured value is within the range specified in
the overall frequency response chart.
Overall frequency response chart (Normal)
50Hz 70Hz
9. Set the bias selector to high and equalizer selector to 70S.
10. Measure as same as manner above.
11. Make sure that the measured value is within the range specified in
the overall frequency response chart for CrOz tape below.
Overall frequency response chart (CrOz)
REMARKS
* Record/playback mode
* Record level control
-- MAX
10