Test And Alignment Instructions - Sennheiser HEV 70 Service

Download v. www.rainers-elektronikpage.de ; gescannt von Rainer Fredel

6. TEST AND ALIGNMENT INSTRUCTIONS

No. Measurement, Signal input
adjustment
1 Current AF signal generator to
consumption J1 (R and L channel):
200 mVeff / 1 kHz
1.1 Operating voltage as 1.
2 Reference voltage as 1.
3 Converter as 1.
frequency
4 Operating voltage as 1.
+ 600 V
4.1 Operating voltage as 1.
+ 10 V
4.2 Operating voltage as 1.
– 10 V
4.3 Output stage as 1.
bias voltage
5 Polarisation as 1.
voltage
6 AF amplifier as 1.
6.1 AF amplifier as 1.
6.2 Output voltage if outputs are clipping
decrease AF signal
generator voltage
down to 180 mVeff
7 THD as 6.2.
8 Frequency AF signal generator:
response 60 mVeff / 1 kHz
8.1 Frequency Check frequency
response response with
AF signal generator
from 20 Hz to 20 kHz
NOTES:
Preparations, settings Test point
Switch S1 "ON" Input
volume control current
R104.1 and R104.2 "cw";
DC ammeter
as 1.; TP1
DC voltmeter
as 1.; MP1
DC voltmeter
as 2.; MP2
Oscilloscope
as 2.; MP3
DC voltmeter
as 2.; MP4
DC voltmeter
as 2.; MP5
DC voltmeter
as 2.; MP6 (+R)
DC voltmeter MP7 (–R)
MP8 (–L)
MP9 (+L)
as 2.; MP10
DC voltmeter
as 2.; MP11 (R)
UPM 550 - 1 and MP12 (L)
Oscilloscope
as 2.; MP13 (R)
UPM 550 - 1 and MP14 (L)
Oscilloscope
as 2.; MP15 (+R)
UPM 550 - 1 and MP16 (–R)
Oscilloscope MP17 (–L)
MP18 (+L)
as 2.; MP15 (+R)
UPM 550 - 1 and MP16 (–R)
Oscilloscope MP17 (–L)
MP18 (+L)
as 2.; MP15 (+R)
set indicated value to MP16 (–R)
reference level, adjust MP17 (–L)
UPM 550 - 1 to 0 dB MP18 (+L)
(Uncal. - Adjuster)
MP15 (+R)
MP16 (–R)
MP17 (–L)
MP18 (+L)
Desired value Adjuster
210 - 230 mA R128
(minimum)
24 - 28 VDC
5.1 VDC
> 60 kHz
580 - 600 VDC
10 VDC
– 10 VDC
300 ± 15 VDC
255 VDC
190 - 200 mVeff
190 - 200 mVeff
180 - 200 Veff
k < 0.3 %
U = 0 dB
– 2 ... 0 dB
Remarks
LED D29 "red"
please see
pattern on
page 7
Output voltage
is not clipping
LED D29
"green"
HEV 70
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