Sony TC-252 - Page 8

Sr ea won ae ee
i
Item | Signal Source Output Connection Remarks
pearance eset |
1. Record/play back PONS Alignment Lape J-19-F 1) yryM and 8a resistor in azimuth alignment screw |
Head Azimuth Ist tone, JOkKHZ(AMPEX Align-| parallel with SPEAKER playback See Fig. 1. Adjust for maximum VTVM reading. |
tone,
15
kHz)
or
equivalent
|
| 2, Bias Trap | | hee L101 (for CH-L) 1. Set CH-L (CH-R) VOL control to MAX and CH-R (CH-L) to MIN, |
Aaieaenent no signal same as ltem | P . “ns : L201 (for CH-R) | 2. Place CH-L (CH-R) in playback mode and CH-R (CH-L) in record mode.
| | | poe ne See Fig. 2. : 3. Adjust L101 (L201) for minimum VTVM reading on CH-L (CH-R).
ee re eg ar errr fb —— - ~——— — —- es eee
3. Level Meter 1 kHz, -60 dB (78 nV) | R145 (for CH-L) | 1. Adjust CH-L (CH-R} VOL control to obtain 0 dB (0.775 V) on VIVM.
Calibration to MIC jack | same as Item | record R245 (for CH-R) 2. Adjust R145 (R245) so that the level meter indicates 100 on the scale.
| see Fig. 2. | |
i
a
reny
4. Recording Bias
Adjustment
i. Before making adjustments, be sure to clean heads with cloth or swab
dampened with denatured alcohol and to demagnetize record/playback head
with a head demagnetizer (SONY HE-2).
The adjustments should be made in numerical order.
The switches or controls should be set in the following positions:
SOS switch: OFF SPEAKER switch: 2 TONE control: HIGH
4. The adjustments should be made at 74% ips (19 cm/s) tape speed.
5. After adjustment, apply lock paint to the parts adjusted,
Lad IND
head azimuth atignment
screw
Fig. 1 Adjusting parts location for item 7
VTVM across record/
playback head
record
CCE Bs oe
tap of bias osc.
transformer T302
or more. See note 7 below.
Make sure that bias voltage across record/play back head is 20 V
| If not, change taps of osc. transformer T302. |
6. The following test equipment is to be used for the adjustments:
* Audio signal generator _ * Resistor 82 10W 7
* Attenuator 6002 * SONY Alignment Tape J-19-F 1 (AMPEX
* WVITVM : Alignment Tape 01-31321-04) or equivalent.
7, Bias voltage across heads should be read on VTVM as follows:
record/playback head: approx. 21 V
erase head: | approx. 45 V
“ Rias (for CH-L meter level adj.}
£101
(for
CH-L
bias
trap
edj.}
Fig. 2. Adjusting parts location for iterns 2 and 3
Thy omy oy care ties fepey rd ;
Redd BAGE gists feeariy re
afar Ea P57) oy an
AIAG, BIB a
Fig. 3 Mounting diagram of bias osc. section