Trio VT-126 User manual

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VT-126
(VT-125)
HIGH SENSITIVITY VOLTMETER
(NOISE METER)
INSTRUCTION MANUAL
~TRIO

2
GENERAL
The Noisemeter is an ultra-sensitive electronic voltmeter
having a maximum sensitivity of 1O#V fullscale (:lO pV, tor
the VT -125) Its wide frequency range covers from 10 Hz to
500 kHz (1 mV ~ 300V) and the five types of weighting are
selectable. In addition, DIN or CCI R quasi-peak or average
detection
with RMS display is selectable. making possible
S/N and noise measurements in accordance with JIS-A.
DIN NOISE, DIN AUDIO. CCIR and CCIR/ARM standards
The
units are also provided with an overload indicator and a
10 dB range relative reference adjustment. AC and DC out-
puts are provided and remote control of range switching is
available to facilitate use on the production line.
CONTENTS
GENERAL .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. .. .. .. . 2
FEATURES ................................................. 2
SPECIFICATIONS...................................... 3
CIRUIT DESCRIPTION .............................. 9
CONTROLS AND INDICATORS ................ 10
OPERATION .............................................. 13
PRECA UTI 0 N ............................................ 14
MAINTENANCE ......................................... 15
ADJUSTMENT ........................................... 15
APPENDIX ................................................. 17
PARTS LIST ............................................... 21
P.C. BOARD AND
CIRCUIT DIAGRAM ................................ 30
* VT-126: 10 J.N fullscale maximum sensitivity with 0.2
J.N graduated scale for measurements down to
-120 dB
VT-125: Maximum sensitivity of 30 J.-tV fullscale.
*Button selection of JIS-A DIN NOISE. DIN AUDIO. CCIR
and CCI R/ ARM weighting filters make possible noise
measurements and
S/N measurements in accordance
with a variety of standards.
* In addition
to average detection and RMS display, DIN
and CCI R semi-peak detection with R MS display is
available for measurements in accordance with those
standards.
*
AC OUT and DC OUT terminals are provided to facilitate
waveform observation, recording of measured values or
use
of the unit as an amplifier.
* A relative reference
adjustment from 0 ~ - 10 dB
makes possible relative measurements
of signals with
respect to an arbitrarily set reference level. particularly
useful in
S/N measurement.
*
An overload indication prevents measurement errors
caused
by distortion not detected by the operator by
viewing the meter level for use with the weighting filters.
* Logic control is used
for range selection making this func-
tion remote controllable (option).

ITEM
VOLTMETER
t----
Voltage ranges:
Display accuracy:
Frequency response:
SPECIFICATIONS
VT-126
101N -~ 300V
I10,.tV/301JV/1001'V/3001'V/1 mV/3 mV/10 mV/
30 mV/ 100 mV/300 mV/1 V/3V/10V/30V/100V/
300V fullscale)
dB - 100 -~ t 50 dB IO dB =c 1 V)
dBm -98 ~ +52 dBm IO dBm = 1 mW/600)
With average detection, in FLAT mode
10 11 V and 30 11V range within :+: 5% of fullscale
1 0011V -~ 300V range within ±3% of fullscale
With quasi-peak detection and DIN NOISE.
DIN
AUDIO or CCI R weighting filter
10 11V range: withm 17% of fullscale
30
11
v -~ 300V range within ±5% offullscale
With average detection and RMS drsplay
10
11
V range: 20Hz -~ 10kHz
10Hz~ 30kHz
30
11
V -~ 300 11V ran~w 20Hz ~ 20kHz
10Hz-~ 100kHz
1 mV ~ 300V range 20Hz ~ 100kHz
15 Hz ~ 300 kHz
1
0 Hz ~ 500kHz
With quasi-peak detection and RMS display
1011Vrange 30Hz-~ 15kHz
20Hz ~ 20kHz
10Hz-~ 30kHz
+5%
±10%
t 5%
_1_10%
±3%
_t5%
±10%
+5%
+10%
+20%
j
VT-125
301'V ~ 300V
130 11V/100 IJV/300 11V/1 mV/3 mV/10 mV/
30 mV/100 mV/300 mV/1V/3V/10V/30V/100V;
300V fullscale)
dB -90~t50dBIOdB=1V)
dBm -88 ~ +52 dBm IO dBm = 1 mW/600)
t-------~--------------------------~-----
With average detection in FLAT mode
30 11V range: within t 5% of fullscale
10011V -~ 300V range wrthrn +3% of fullscale
With quasi-peak detection and DIN NOISE,
DIN
AUDIO or CCIR weighting filter
301'V ~ 300V range within t 5% of fullscale
'- ----------------~
With average detection and RMS display
30 11V ~ 300
11
V range 20Hz ~ 20 kHz
10Hz~ 100kHz
1 mV ~ 300V range 20 Hz ~ 100kHz
15 Hz ~ 300kHz
10 Hz ~ 500kHz
With quasi-peak detection and RMS display
+5%
±10%
±3%
t5%
+10%
3

ITEM
VT-126
VT-125
30 llv ~ 300V range: 30Hz ~
20kHz
±5%
30 llv ~ 300V range: 30Hz ~
20kHz
±5%
20Hz~
50 kHz
±10%
20Hz~
50 kHz ±10%
10 Hz ~ 100kHz
±20%
10Hz~ 100kHz
±20%
------------·---------
Input impedance:
1 Mil ±5%
1 Mil ±5%
Parallel capacitance: Less than
50pF
Parallel capacitance: Less than 50pF
-~--------·---
Overload voltage
10pV
~
300pV range: AC
10 Vrms
30 pV ~
300!-lV range: AC
10Vrms
level:
DC 500V
DC 500V
1 mV
~
300mV range: AC 80 Vrms
1 mV
~ 300 mV range: AC 80 Vrms
DC +AC peak 500V
DC +AC peak 500V
1V
~ 300V range
DC +AC peak 500V
1V -~
300V range:
DC r- AC peak 500V
-------
Relative reference
0 ~ approx. -12 dB 0
~
approx.
-12 dB
adjustment:
----------·
. ----------~--------- --
Over level:
Lights up or fl1ckers when a signal of more than + 15
Lights up or flickers when a signal of more than + 15
dB for max1mum value is applied
dB for maximum value is applied.
This indicates that there is a possibility of erroneous This indicates
that there is a possibility of erroneous
Indication due to over input when a level weighting
indication due to over input when a level weighting
filter is used
filter is used
Residual noise:
Average detection:
Average detection:
10 llV range input shorted
Below 1.5 llVrms (1.0 pVrms TYP.)
30 llV range input shorted
30pVrange input shorted
Below 5 llVrms (3.0 llVrms TYP.)
Below 5 llVrms (3.0 llVrms TYP.)
4

ITEM
Full operating range:
Distortion:
VT-126
Peak detection:
10 11V range input shorted
Below 2.0 11Vrms (1.0 11Vrms TYP)
30 11V range input shorted
Below 5 11Vrms (3.0 11Vrms TYP)
0 08%/' C or less (Minimum 1 mV range)
35"C. 80% maximum.
0 ~ 50 'C. 80% maximum.
Approx. 1 00 dB
1
Vrms ±10%
600!1 ±10%
Below 1% of fullscale at 1 kHz
This
distortion is determined by the S/N for
the ranges
10 11V ~ 300 11V
VT-125
Peak detection:
30 11V range input shorted
Below 5 11Vrms (3.0 11V TYP.)
-~-------~~---------------~~--·-~----t
or less (Minimum 1 mV range)
·---~----~~------!
15 .~ 35°C, 80% maximum.
0
50"C. 80% maximum.
----------~~------------4
Approx. 90 dB
-- ---~--·---- -----~--- -----4
1 Vrms ±10%
---- ------------------~---j
Below 1% of fullscale at 1 kHz
This
distortion is determined by the S/N for
the ranges 30!1V ~ 300!J.V.
5

6
ITEM VT-126 VT-1:25
f-----
S/N:
-----------~~--t-- --------- --
With respect to fullscale:
With respect to fullscale:
1 mV ~ 300V range: 40 dB minimum 1 mV ~ 300V range: 40 dB minimum
300!-LV range: 30 dB minimum 300 11V range: 30 dB minimum
10011V range: 25dBminimum 10011V range: 25dBminimum
30 11V range: 20 dB minimum
30 11V range: 20 dB minimum
10 11V range: 16.5 dB minimum
!--------· --·-··---------· ·--------··-··--·-------- ·------ ------·--·---t----···- -------------
e-.
Frequency response: 1 mV -~ 300V range: 10Hz ~ 500kHz 1 mV ~ 300V range: 10Hz ~ 500kHz
within ±3 dB
30 11V ~ 300 11V range: 10Hz~ 150kHz
within ±3 dB
range
10 H ~30kHz
within ±3 dB
DC OUTPUT AMPLIFER:
within ±3 dB
30 11V ~ 300 11V range: 10 Hz ~ 150kHz
within ±3 dB
c-~:;u-t--v--o-lt_a_g_e--:~~~-.-1-V_±_1_0_'7<_o_fo--r--f;;l,;:;l;- - -- - -- ---- f;_; f 10% fo;f"ll;;~,,
1---~~--~------- --1-----------~------- -------------- --------- --- ----- ---~
Output resistance: 600\l ± 10% 600!1 ± 10%
~--- -----------+------- --------------------- ------~----- ----- --------~
f-~r~q~_EI_~~~-res_JJ_onse: _ Approx_the sa_me as the_ m_e~e~-~~~lcat~n- __ __ A~prox~~~~-e_ as !h_EJ _rr~~~~~~~~~tiOn ____ _
POWER SUPPLY SECTION
1-~~~~~-~---- ---------- --- ------- --- --------------- -------------------~-----~~-1
Supply voltage: 1 00/120/220/240VAC ± 10% 50/60Hz 1 00/120/220/240VAC ± 10% 50/60Hz
1--~--------- j-------------------------------~---------r------------------ ----- ----- ------------
Power consumption: Approx 15W Approx 15W
-------- -- ------------- j----- ------------- ---------------- - - ------
Dimensions: Width 128 mm Width 128 mm
Height
190 (214) mm Height 190 (214) mm
Depth 285 (315) mm Depth 285 (315) mm
( ) dimensions include protrusions from the basic
case. ( ) dimensions include protrusions from the basic
case.

ITEM
---------------- --------
Weight:
Accessories:
4 6 kg
Power cord ..
Input cable (CA-41) .
Instruction manual.
VT-126
4 6 kg
_1 Power cord ..
Input cable (CA-41).
Instruction manual
VT-1 25
7

CIRCUIT DESCRIPTION
il . FIRST ATTENUATOR
A reststive dtvtder attenuator which IS relay switched
between 0 dB ( 10 pV ~ 300 mV range) and ·· 60 dB (1V
~ 300V ran~Je). For the other ranges tt is not 111 the circuit
3. IMPEDANCE CONVERSION CIRCUIT (01 ~ 03)
Used to convert the output of the f1rst attenuator to a suf·
ftctelltly low Impedance to dnve the second attenuator An
FET tnput voltage follower is used in this circuit. (1 mV ~
300V range)
5. SECOND ATTENUATOR
A reststtve dtvtcier attenuator tn two secttons. 0 dB or 30
dB rr)lay selected and 0/ 10/ 20/ 30 dB four step FET
swttched selected sectton Thts attenuator outputs a
1
mVrms stgnal for fullscale meter deflectton.
2 AND 4 PRE-AM~LIFIER AND FILTER (04~08.
0201,0202) For the 10 /J.V. 30 /J.V. 100 !IV and 300 J.LV
ranges the signal ts ampltfied 1 00 times and passed to the
filter. (0201 and 0202 ts not used in VT·125)
6;. MAIN AMPLIFIER (011 ~ 014)
A wtdeband non mvert1ng amplifter Wtth a d1fferent1al 1nput
of ht(lh trnpedance and low output 1mpedance The (Jilin tn
40 dB and the output ts 40 rnVrms for a fullscale deflectton
7. FILTER AND FILTER SELECTION CIRCUIT
FLAT. DIN NOISE. DIN AUDIO. CCIR and CCIR/ARM
wetohttn~J filters and the associated selection circuitry.
,g. OVERLEVEL CIRCUIT (IC2, IC3, 015)
Thts ctrcutt uses peak detectton of a full-wave recttf1ed stgnal
to detect excr;sstvely htgh stgnal tnput levels An LED dts·
play warns of excesstvely htgh tnput
c9). IMPEDANCE CONVERSION CIRCUIT
Thts ctrcult converts the filter output to a sufficiently low im·
pedance
·10). AVERAGE DETECTION CIRCUIT (04 ~ 09)
Tilts circuit detects the average absolute stgnal value and
provtdes a meter drive stgnal for an RMS display of stgnal
level
C11!. QUASI-PEAK DETECTION CIRCUIT (IC1 ~ IC4)
Thts ctrcutt detects the peak-to-peak stgnal value and
fj8nerates a meter drive signal representing the RMS value
of the stgnal tn accordance with CCIR standards.
1?). AC OUTPUT AMPLIFIER (010 ~ 012)
Thts ctrcutt amplifies the signal from block@ to prov1de an
output s1gnal of 1 Vrms for fullscale deflection of the meter
(JJ). DC OUTPUT AMPLIFIER (IC5. IC6)
Thts ctrcuit ampliftes the St(Jnal from the meter terminals to
provtde a DC output of 1V for fullscale meter deflectton.
9

10m
(4)
10
CONTROLS AND INDICATORS
NDISE:MfT£R VT~1(?6
'<,> ~J
___:.:,,_'_:_' ---l~-(1 0)
RANGf
f.'
]On, lOOn•
IOOro
JOOV
-
(3)
Fig. 1
FRONT PANEL
1. POWER
AC power switch.
2. POWER LAMP
Indicates the VT-126 (VT-125) is powered up. Lights when
POWER is depressed.
3. RANGE
Attenuator selector switch. 16 positions ( 15 for the VT-
125) in 10 dB steps. To prevent excessive inputs, this
switch is started in the highest. 300V range and gradually
worked down range to provide an easily readable meter
deflection
4. INPUT
BNC signal input connector.
5. RELATIVE REF AND 6. UNCAL LAMP
Sensitivity adjustment and uncalibrated annunciator. More
than 10 dB of adjustment is possible. When the control is
turned fully clockwise. the set range is calibrated. This con-
trol can be used to adjust the meter to an appropriate level
for relative measurements. When not set at fully clockwise
the UNCAL lamp lights to warn the operator.
7. OVERLEVEL
When using weighting filters the effect of the filter is to
mask from the operator the presence of an excessively high
input level. Thus distortion and the resulting errors can oc-
cur
without the operator being aware of this condition To

prevent this the OVERLEVEL warning lamp alerts the
operator when the 1nput level goes I 15 dB above the full
scale level (0 dB)
8. AVERAGE/PEAK
Th1s sw1tch 1s used to select the detection method. In the
released pos1t1on average detection and RM S display are in
effect Depressmg the switch selects either DlN or CCI R
quasi-peak detection and RMS display of the signal level.
When CCI R/ ARM is selected the detection method IS
automatically switched to average detection and R MS dis-
play regardless of the position of this switch.
9. WEIGHT
Th1s s1x posit1on select1on SWitch group allows selection of
one of FLAT or JIS-A. DIN NOISE. DIN AUDIO, CCIR or
CCIR/ARM we1ghted response. Selection of the FLAT posi-
tion turns the un1t into a wideband AC voltmeter. If no but-
ton IS depressed. the mode is automatically CCIR/ARM
JIS-A Used for noise level measurements 111 accordance
with JIS C1502A. JIS C5551A, IEC-A. and IHF-A stan-
dards.
DIN NOISE. Used for no1se level measurements in accor-
dance w1th DIN standard 45405.
DIN AUDIO. Used for 10Hz~ 20kHz aud1o level
measurements 111 accordance with DIN standard
45405
CCIR Used for measurements of no1se level 111 accordance
w1th CCI R standards for measurements.
CCIR/ARM Used for no1se level measurements in accor-
dance w1th CCIRiARM standards for DOLBEY B type
no1se reductiOn systems. When the CCI R/ ARM filter IS
used. average detection is used regardless of the posi-
tion of the AVERAGE/PEAK switch.
The appropriate AVERAGE/PEAK switch settings for the
va
no us filters are:
Filter AVERAGE PEAK
~ ------· ----------· - _ _._. ______ .. __ f----------
JIS-A 0
:..:..=...:....: __ ~--------1-----~=--------- -------------
DIN NOISE 0
------~--------+-------~-------- .. ---
DIN AUDIO 0 0
CCIR
---~--- ----- ------r--------------t-------~---~-
CCIR/ARM
0
10. METER
11

(I
Fig. 2
12
REAR PANEL
11. AC OUTPUT
This output IS used for waveform observation or for used of
the VT-126 (VT-125) as an amplif1er.
12. DC OUTPUT
This output is used for recording off-line measured values
13. GND
Ground connection
14. FUSE HOLDER
Use a screwdriver to open this holder for replacement of the
fuse of specif1ed ratmg
For 100 or 120V 05A
For 220 or 240V 0 3A
15. AC POWER CONNECTOR
Th1s IS the AC power 1nput connector Use the power cord
provided w1th the unit.
16. AC LINE VOLTAGE SELECTOR
Set the plug of this selector to the local lme voltage
(1 00/ 120/220/240V AC)
17. BLIND COVER
This cover protects the remote control mountmg hole

OPERATION
1 Check the mechan1cal zeromg of the meter.
2 Connect the s1gnal cable to INPUT (4)
3
Set the RANGE switch (3) to the 300V range.
4
Connect the power cord and press the POWER ( 1)
sw1tch to turn the un1t ON. The red LED (2) should l1ght
md1cat1ng
the un1t IS ready for use.
5
Input the s1gnal to be measured and 1f necessary
(Jradually sw1tch to lower (more sensit1ve) ranges until
an easy to read meter deflection IS obtamed.
USING RELATIVE REF
To make measurements With respect to some arbitrary
reference level, rnput the signal to be used as the reference
level and use RELATIVE REF (5) to obta1n a 0 dB meter
deflect1on Without chang1ng the RELATIVE REF setting
measurement of other s1gnals can be made and read d1rectly
off the dB scale 1n dB w1th respect to the reference level.
The adjustment range of the RELATIVE REF control IS from
0 to -- 12 dB (negative only) so to set 0 dB for signal under
0 dB sw1tch1ng down range must be done
READING THE METER SCALES (See Fig. 3)
1. VOLTAGE SCALES
These scales consist of a 0 ~ 10 and 0 -~ 3 scale which are
used to read ranges which are multiples of 10 and 3 respec-
tively. The range setting always refers to the meter fullscale
deflection. The ranges are designed to overlap to allow
values on the lower portion of one range to be more ac-
curately read on the upper portiOn of the next more sensitive
range.
2. dBm SCALES
A level of 1 mW 1nto a 60011 resistance is take as 0 dBm
(0 775V) and read1ngs are made 111 0 dBm with respect to
th1s standard reference level.
VOLTS DECIBELS
Fig. 3
13

14
PRECAUTIONS
1. To assure accurate measurements allow a five minute
warming up period before actual measurements are
begin.
Note that switching between 1V and 300 mV
and between 1 mV and 300 11V and 10 11V upon power-
ing the unit up may result in the deflection of the meter.
2. To preserve the high
sensitivity of this unit, be sure to
use either the input signal cable provided or another low
capacitance shielded cable. Use of stngle conductors or
other unshielded cables or high impedance s1gnal
sources can result in noise being introduced into the
measurement circuit.
3
Be sure to take care not to exceed the maximum
allowable input levels:
10 1N ·~ 300 11V ranges: AC: 1OVrms
(30 11V ~ 300
11
v range DC: 500V
for VT-125)
1 mV -~ 300 mV ranges: AC: 80Vrms
DC+ AC peak 500V
1V ~ 300V ranges: DC+ AC peak 500V
For excessively high inputs in the 10 11V to 300 11V
ranges the input impedance drops to approximately
10011
4 Please note that this unit OVEF!LEVEL LED lights when
the input exceeds 15 dB above the fullscale reading for
use with weighting filters to warn against distortion due
to highly excessive signal levels. It also normally l1ghts
when switching between the 300V and 1V or between
the 300 11V and 1 mV ranges. but this is normal and not
an indication of excessive signal level.
5 The dynamic range of the units is 40 ~ 80 dB making it
impossible to measure the internal weighing filter's
frequency response while they are installed in the unit.
6. A signal or DC voltage should never be placed between
the instrument case and ground.
7. When this instrument is used in a location where the AC
line has pulse noise of a level higher than the internal
filter can handle, performance may be affected Con-
sideration should be given to providing a clean power
source in such a situation.
8. Temperature coefficient ( 10 11V ·~ 300 11V range for the
VT-126 and 30 11V ~ 300 J.N range for VT-125) is
0 1 %/°C TYP.

MAINTENANCE
Removing the CASE
Using a screwdnver. remove the two screw each on the left
Side. nght Side and top of the mstrument Open the bottom
of the receptacle shaped case to remove the cover
Removal of the four screws retarnrng the bottom cover will
expose the shreld
Selection of Power Line Voltage (See Fig. 4)
To set this instrument up for use wrth 100, 120V AC re-
insert the power lrne voltage selector plug at the rear panel
to appropnate position. Note that for use at 100 or 120V
the fuse should be changed to a 0.5A unit
·-·~·
........
' I
Fig. 4
ADJUSTMENT
Although this rnstrument is shipped 111 a calibrated and ad-
JUSted state. should recalrbratron be necessary, perform the
procedures outlrned below usmg calibrated rnstruments after
venfyrng that the lrne voltage settrng rs correct
Meter accuracy adjustment
1 Remove the case and bottom cover.
2. Wrthout applying power mechanrcally zero the meter
usrng the zero adjustment screw.
3 Usrng a meter calibrator apply erther a 400Hz or 1 kHz
Signal to the INPUT (4) of thrs rnstrument
4 Set the AVERAGE/PEAK switch (8) to AVERAGE and
the WEIGHT swrtch (9) to FLAT
5 Set the meter calibrator output to 10 mV and the meter
RANGE swrtch (3) to 10 mV Adjust VR2 of the Output
Unrt (X73-1390-00) for a fullscale deflection of 10 mV
6 Set the meter calibrator output level to 30 mV and the
meter range swrtch to 30 mV Adjust VR4 on the Input
Unrt (X73-1 380-00) (bottom side) for a fullscale
deflectron
Next set the meter calibrator output level to 1V and the
meter range switch to the 1V range. Adjust VR 1 of the
Input Unit for a fullscale deflection.
7 For adjustment of the 10 ,,v to 300 ,,v ranges (30 1N to
300,uV ranges for the VT-125). use a calibrated
resrstive attenuator to obtarn an output of 100 ,uV. Set
the meter range to 100 ,uV and adjust VR2 of the Input
Unit for a fullscale deflection.
15

16
8 To adjust the 10 11V range of the VT-126, set the
calibrator output to 10 11V and set the meter range
switch to the 10 11V position. Adjust VR201 of the In-
put Unit for a fullscale deflection.
9 Depress the AVERAGE/PEAK sw1tch and leave the
WEIGHT switches in the FLAT condition. As was done
in step 5, adjust VR7 of the Output Unit for a fullscale
deflection.
10 Remove the calibrator and connect a wideband os-
cillator to the IN PUT. Set the oscillator frequency to 1
kHz and the meter range switch to 1V Adjust the os-
cillator
output level for a fullscale deflection in this con-
dition.
11. Shift the oscillator frequency to 100 kHz and use the
TC 1 on the Input Unit to adjust the meter for fullscale
deflection
12 Repeat the above procedure
AC-DC OUT adjustment
Depress the AVERAGE/PEAK switch on the panel and leave
the WEIGHT switches in the FLAT condition.
AC-OUT adjustment
Apply a signal so that the meter reads for fullscale.
Adjust VR8 so that the AC OUT is 1 Vrms.
DC-OUT adjustment
Short circuit the input and adjust VR 10 so that the DC OUT
is OV Apply a signal so that the meter reads for fullscale.
Adjust VR9 so that the DC OUT is 1 V. Repeat above
procedure until the specified value is obtained.
Adjustment of Weighting Filter Reference
Level
The reference level of each filter is adjusted so that th1s level
(the 0 dB level on the weightlllg curve) yields the same
measured value as the FLAT cond1ton Use a frequency
counter to accurately set the frequency of the oscillator for
this adjustment.
Filter Oscillator
We1ghtmg
Unit
frequency
Control
---------
JIS-A
VR1 1kHz
DIN NOISE VR2 1kHz
---------- r------ -------------
DIN AUDIO VR3 1kHz
Adjust
For
OdB
indication
----------
OdB
tnd1cat1on
0 dB
indtcat1on
----------+------ ------------ -----f--- -----------
CCIR
VR4 63kHz
12
·2 dB
md1cat1on
------+-----f-----·--------· -1---- ------
6.6 dB
CCIR/ARM
VR5 6.3kHz
1nd1cat1on

APPENDIX
W1th regard to CCIR recommendations and DIN 45405
standards for sem1-peak detect1on of no1se levels. the follow-
Ing charactenstJcs are specified
1 One tone burst 1s to be mput and the measured value to
be venf1ed to be w1thm the l1m1ts surnrnanzed below
The tone burst is to be sine wave of 5kHz frequency.
The duration times are listed in the table below.
2 Input a tone burst s1gnal as shown below and venfy a
1esponse W1th1n the IJmJts shown below The tone burst
frequency 1s 5 kHz
1) Noise Measurement Filter JIS C1502A, JIS
C5551A IEC-A, IHF-A
Frequency
Response Responsed
Frequency
Response Responsed
tolerance
tolerance
(Hz( (dB) (dB) (Hz)
(dB)
(dB)
r--
;! ~)
2000 I 2 I I 0
f-----
- --------
il
~ J 2:000 2 I 0
-------
40 31:10 "
1.0
- ,_
-------- --
---- --
-----
~,C)
4000 I
()
I
()
---- ------
(d
5000
() :,
1.0
1---
--
so
6300
0 I I I I
()
---
---
](I()
8000 I I
()
------
----
12'-,
10000 2 ~ 1.0
---- -
160 13 2 12')00
~
? I 2 0
-------
-- ------
?00 10
8 lbOOO 6 " 2
()
2~J0 i:l .6
Jl :,
(,
cJ
~Otl 4
i:l
',()()
:1
2
(J.l()
_q
800 0.
8
1000 0
12:)0
0. b
1600
_()
1.0
17

2) Noise Measurement
Filter DIN 45405 (NOISE)
Frequency Response Responsed
tolerance
(Hz) (dB) (dB)
0 I 0. 5
I C>.3 . 5
I 8.2 .5
I 8.4 I 0 5
20000
31500 30
18
3) Noise Measurement
Filter DIN 45405 (AUDIO)
Frequency
(Hz)
1--------
4
1---·--
10
1----
31."
1----.
1000
1------ , ....
20000
1--..
25000
Response Responsed
tolerance
(dB) (dB)
........ -+- ·-·--
20
---·--·- ----
5
-·-·-··- .......... -
0 I 0 5
.......... -1-- ,....... -
0 I 0. 5
---- ... ...... ----
0 I 0. 5
3
50000 40
4) Noise Measurement Filter (CCI R standard).
(Rec 468-2)
Frequency Response Responsad Frequency Response
tolerance
(Hz)
(dB) (dB)
(Hz)
(dB)
1----
31
.5
29.9
20000
22
.2
31o•OO 42.
1. 9
0
~) b
I 9 0
I
10.5
10
I 11.7
12. 2 0
I 12
.0
11 .4
I 10.
I
8.
0 I I .2 Ill
5.3
I I 11t
16000 11.7
' 1 6511'
Responsed
tolerance
(dB)
......... _
I 2.0
....... -
' 2. 8 II)
00

5) No1se Measurement Filter
(CCIR/ARM standard)
Frequency
)Hz)
ll
~)
(,:,
100
200
401)
j
20000
Response
(dB)
-)r_)
'>
?Cl
:,
j~)
~
]CJ 4
J:i 4
:,
b
0
3 4
4. 9
(J
(,
(;
4
')
s
,,
?
,,
')
b
10 y
I 7 j
~! 1 s
Responsed
tolerance
(dB)
I ? 0
·?
Frequency Response Responsed
tolerance
(Hz) I dB)
(dB)
~- -
11 •,oo
~H.:'
I t 8
rx:
19

+10
0 I
..
I
• t.
I
I I 1
•• j
! '
' t I
-40
Frequency (Hz)
N01se
. Weighting
Characteristics
20