IRT VA-100NC User manual

I
IR T ElectronicsPty.Ltd. A.C.N. 000832575
26 Hotham Parade, ARTARMON. N.S.W. 2064 Australia
National: Phone: [phone]Fax: [phone]
International: [phone] [phone]
VA-100NC
VIDEODISTRIBUTIONAMPLIFIER
Telecom Serial 347 Item 55
802995
21-10-1991
DESIGNED AND MANUFACTURED
IN AUSTRALIA
IRT Communications
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VA-100NC
VIDEO DISTRIBUTION AMPLIFIER
INSTRUCTION BOOK
Serial 347 Item 55
Section Contents Page
1. General Description 3.
2. AccessoriesAvailable 4.
3. Technical Specifications 5.
4. CircuitDescription 6.
5. Installation 7.
6. Setting up Procedure 7.
7. Maintenance 8.
8. Table of Voltages 9.
9. CircuitDiagrams
10. PartsLists
WARNING
OPERATION OF ELECTRONICEQUIPMENTINVOLVES THEUSEOF VOLTAGES
AND CURRENTSWHICH MAYBE DANGEROUS TO HUMANLIFE.OPERATING
PERSONNELSHOULDOBSERVE ALL SAFETYREGULATIONS. DONOT CHANGE
COMPONENTS OR MAKEADJUSTMENTSINSIDE THE EQUIPMENTWITHPOWER ON
UNLESSPROPERPRECAUTIONS ARE OBSERVED. NOTETHATUNDERCERTAIN
CONDITIONSDANGEROUSPOTENTIALS MAY EXIST IN SOMECIRCUITSEVEN
THOUGHPOWERCONTROLS AREINTHEOFF POSITION.
802995
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GENERAL DESCRIPTION
The VA-100NC isa B.C. poweredVideoDistributionAmplifier
of modularconstructionhavingfacilities for cable equalization,
longitudinal hum reduction and clamping.
The input is designed to provide a bridgingloopimpedance
over the videobandwidthwithrespect to75 ohm. Six75ohm D.C.
coupledoutputs are provided.
The input and outputgrounds are separated to allow for
rejection of longitudinallydevelopedhum.
Cableequalization is provided forupto300 metres of75ohm
videocable.
Front panel controls allow the videogain tobe varied bya
minimum of+/- 3dB, andthe cableequalisation tobe
independently setto compensate forthe appropriatelength of
cable.Internal pre-set controls allowadjustment ofthe
amplifierhighfrequency response, optimization ofthe
longitudinal hum rejection, and outputstageD.C.component.
The VA-100NC is operatedfromnegative 48V D.C.
Equipment provided:-
1 VA-100NCVideoDistributionAmplifier
1 SlideTray
1 RB-1NRearAssembly
802995
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ACCESSORIES AVAILABLE
F-100D ModuleMountingFrame :-
Providesmounting forupto10
VA-100NCamplifiersside by side
in 134mm of standardRackspace.
(3 Rack Units)
TME-1AModuleExtender:Enables a module
to be operated in position and provide
access toall circuitboards,transistors
and internaladjustments.
RB-1NRearAssembly: An additionalrear
assembly maybe purchased to permit
benchtesting and servicing ofthe
amplifier withoutdisturbing the
rearassembliessuppliedwith the
amplifiers.
802995
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SPECIFICATIONS
Inputpower
INPUTCHARACTERISTICS
Inputimpedance
Inputconnector
Longitudinal hum rejection
Maximum level
TRANSFER CHARACTERISTICS
Overallgain
High Frequency response
Differentialgain
Differentialphase
Noise
Operatingtemperaturerange
Cable equalisation
OUTPUT CHARACTERISTICS
Number
Impedance
Returnloss
Overload
DC on output
OutputConnector
FRONT PANELFACILITIES
47to53VDC (+veearthed) @
125mA in accordancewith
Telecom AustraliaSpec1002.
Bridging loopinputwith
returnloss>40dB to 6MHZ
1.6/5.6
>40dB
>2V p-p( OdB gain)
>+ 3dB
+ O.ldB to 10MHz
+ 0.2dB to 20MHz
bandwidthexceeds30MHz
<0.5% at 4.43MHz
o
<0.5 at 4.43MHz
>70dB 10kHz to 5MHzunified
weighted
oo
10 C - 55C
Frontpanelcontrolequalising
up to 300m of 75ohmcable
6, dc coupled
75ohms, sourceterminated
>40dB to6 MHz
3.0V p-pon 4.43MHz sinewave
2.5V p-pon pulse
adjustable to0V
1.6/5.6
* Gainadjustment
* Cableequaliseradjustment
* Clamp on/off indication
* Fuse
* Power onLED
802995
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CIRCUITDESCRIPTIONRefer to Drawing no. 802995.
The blockdiagramshowsthat the VA-100NCcomprises :-
(a)An input stage:- which hasa highinputimpedance to
bridge the videosource, an equaliser for correction of input
coaxial cablelosses, anda 75ohm sourceterminatedoutput.
(b)A "plug-in1 area: - for accessories not
Link 2 bypassesthis feature.
yet defined.
(c)An output stage:- with 6 75ohm sourceterminated
outputs.Thisstage may have its blacklevelclamped to0Vby
placing LK1 inthe 'On' position.
(d) Clamp logic:- a syncseparator and backporchsample
pulse generator isfed from the output ofthe Inputstage.Video
from the output ofthe Outputstage is firstly low passfiltered
(to removechroma and noise) and thenapplied toa sampleswitch.
This switch, undercontrol ofthe samplepulse stores ina sample
and holdcapacitor the backporcherrorsignal. If LK1 isinthe
'On' positionthiserror is applied tothe invertinginput ofthe
Outputstage to correct the offset.
(e) Power Supply:- the -48V DC inputvoltage isfedviaan
on boardfuse toa DC-DCconverter. The output ofthe converter
is + and- 15V.Thesesupplies are furtherregulated to+ and-
12V by3 terminalregulators. TheLEDonthe frontpanel is wired
in series with a zener diodebetween +12and-12 Volts. The zener
is to ensurethat theLED extinguishes ifanyoneofthe
regulatorsfails.
Video Clamp
On
LK1
enablesback
porchclamp
Off
disables back
porch clamp
Accessories
Inserted
LK2
by-passes
accessories
Removed
accessories can
be inserted
802995
6
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INSTALLATION
The VA-100NC is suppliedwith a slidetray,rearassembly and
associated hardware, for mounting inan F-100D frame.
SlideTray
The slidetray isa shallowtraywhichsupports the amplifier
in the frame. Itis mounted onthe front and rearcrossmembers
of the frame andis fixed in placewithsteelclips(speed nut
type)provided.
RearAssembly
The rearassembly is mounted onthe rear ofthe framewith
the screwsprovided.Careshould be taken notto overtighten
thesescrews, as excessiveforcewilldamage the thread inthe
mountingframe.
SignalConnections
Signalconnections are made via coaxialconnectorsmounted on
the rearassembly. The inputloop, ifnot usedshould be
terminated in75ohmas should any unusedoutputs ofthe
amplifier.
SETTING UP PROCEDURE
The amplifiershould besetupinthe position in which itis
intended tobe operated.Adjustments can then be madeusing the
intendedlengths of cable and with all outputsterminated as they
would bein service.
The cableequalizingshould besettoits minimum andthe
gain controladjusted to give the required low frequencygain.
Using a suitabletestsignal,such as pulse and bar,multiburst
or sweep, the cableequalization canbe advanced to compensate
for inputcablelosses.
It should be notedthat the equalizers are factory setto
match Beldentype8281 75ohm cable.
Whilst for short runs thisequalizerwill be satisfactory for
most 75ohm soliddielectriccables, for longerruns of some
cables the equalizer may have tobe reset (a factoryadjustment)
or replacedwith a speciallydesignedmodule.
If backporchclamping is required LK1 should beputinthe
'Clamp On1 position andthe Clamp OnLEDonthe frontpanel
802995 7
IRT Communications
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shouldilluminate. If clamping isnot required LK1 should bein
the 'Clamp Off position.
802995 8
IRT Communications
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MAINTENANCE
Oncehavingbeenadjusted the VideoDistributionAmplifier
will needlittleattention. Itis wisehowever to occasionally
check the adjustments as describedearlier.Thiswillalso be
necessaryafter a component has beenreplaced.
Mostfaults canbe readilytraced by checking the B.C.
voltages at variouspoints inthe circuit. The table of voltages
given in this book canbe used asa guide but deviations
sometimes inthe vicinity of +/-1volt canbe expected in some
units. The voltagesshould be checkedstartingfrom the input as
the B.C. conditions ofthe wholeamplifier aresetinthe first
stage, thus a faultearly inthe circuitwillcauseerrors atthe
output.
InternalAdjustments
The followingadjustableresistors and capacitors are
factory setand should notbe adjustedunless a component has
beenchanged.They arenot 'operational1 controls.Before
adjusting anyof thesecontrolsallowtime forthe VA-600 to
reach temperaturestability.
RV3 Hum:-
Adjusted to bestcancel humonthe inputcable. The clamp
must notbein operationduringthisadjustment.
RV1 BC Offset:-
With no inputsignalapplied RV1is used tosetthe junction
of R12R14to zerovolts.
C2 Freq Resp:-
Used tosetthe frequencyresponse ofthe inputstage to
maximal flatnesswhenobserved atthe junction ofR12 R14.
RV4 BC Offset:-
With no inputsignal and with LK1 installed and after
adjustment of RV1, RV4canbe adjusted so that the junction
of R29R30is zerovolts.
C5 FreqResp:-
Used tosetthe frequencyresponse ofthe outputstage.
Maladjustment of thiscapacitor can causeinstability inthe
amplifier underextremeconditions.
802995
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TABLE OF VOLTAGES
Q Emitter Base Collector
1 -0.72 ~0 11.2
2 -0.66 ~012
3 12 11.30.82
4 0.240.82 12
5 -0.25-0.85 -12
6 -0.67 ~0 11.3
7 -0.66 ~012
812 11.31.65
9 0.3 0.98 12
10 -0.2-0.85 -12
11 1.0312.6 12
120 0.670.21
130 0.670.26
14 0.6 0.46-11.97
15 0.981.65 12
16 -0.68 ~012
U12345678
3 ~00 ~0-12 -11.9-0.5 12 -0.14
4 11.94 0 0 -12 -11.65 0 12 11.94
5 150 12
6 0 -15-12
All voltagesmeasuredwith a highinputimpedancemultimeter
under conditions of unitygain. All voltages are measuredwith
respect to earth.Supplyvoltage is -50.0V B.C. Testsignal is IV
P-P compositeStairStep andthe Clamp is off.
802995 10
IRT Communications
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IV P -P
TERMINATED
0-SV P-P
OPTIONAL
PLUG-IN BOARD
f-J ! I
iI I
SAMPLE SWITCH
IV P-P
TERMINATED
6 OUTPUTS
- *6V
INPUT
DC -DC CONVERTER
+ I5V
~*
-ISV
+
-
1
1
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IRT
DftAWN 3&AA Q*TE
•IXI SCALC
VA-lOO NC
BLOCK DIACKAM
8OZ9S5
SHEET
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IRT Communications
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/T PART OF VA— 1OONC CIRCUIT
/ \G CHANGEDCOMPONENTS
IFOR SPECIFICATION 1227
H RV2
, J 2SOR
FT EQ*
R62
1 CUD f '
51R
C16 I
82PT ?
SPECIFICATION 1 5S7
R63
p cm! T — 1
243R
aci7 ciaj_ _
"* 6Op1 SOpT" ^
R64
1 J f
1K1
2C19 C2O_|_ _
"" 6Op 82p~T '
R65
l==l 1
12K
2 C21 C22|
60p 22p |
i
1
9
g
2
© COPYRIGHT
DO NOT COPY NOR
DISCLOSE TOANY
THIRD PARTY
WITHOUT WRITTEN
CONSENT
DRAWN K.N.
CHECKED
ENO. APP.
CONTRACT No.
DLEU
SIZE:
SCALE
TITLE: VA— IOONC
CABLE COMPENSATION TO
SPECIFICATION 1227
SPECIFICATION 1 557
DRAWING No. 8O29B5
SHEET
3OF3
IRT Electronics Pty.Ltd.
ARTARMON NSW AUSTRALIA 2O84-
IRT Communications
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ORIGINAL ISSUE
DATE IT. -3- 84
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IRT Communications
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I.R-T - ELECTRONICS
»TY . LTD .
Replacement PartsList 802995 VIDEODISTRIBUTIONAMPLIFIERASSEMBLY VA-100NC Page 1 of4
! Part No.
PC802994
SFR16T-1R8
SFR16T-4R7
SFR16T-22R
SFR16T-27R
SFR16T-33R
SFR16T-68R
SFR16T-75R
SFR16T-100R
SFR16T-120R
SFR16T-150R
SFR16T-220R
SFR16T-270R
SFR16T-360R
SFR16T-470R
SFR16T-820R
SFR16T-1K
SFR16T-1K2
SFR16T-1K5
SFR16T-3K9
SFR16T-4K7
SFR16T-5K6
SFR16T-10K
SFR16T-12K
SFR16T-22K
SFR16T-33K
SFR16T-47K
SFR16T-82K
Description.
PCS VA-100NC
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM . 25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM .25W 5%
RESISTOR METALFILM . 25'W 5%
RESISTOR METALFILM .25W 5%
Qty
1
1
2
7
1
1
1
2
2
1
1
2
3
1
4
3
5
4
3
2
4
3
1
1
i
1
1
1
Get Ref.
R8
R29,30
R5, 6, 12,13, 19, 20, 61
RIO
R27
R60
R14,17
R62,67
R74
R18
R3,4
R22,46,71
R63
R15,16,25,57
R7,21,72
R28/41-43,69
R9, 11,64, 70
R23,24,75
R2,68
R48,51,54,65
Rl,49,52
R26
R56
R50
R53
R55
R58
Sup!
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802995 17/10/91
IRT Communications
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I.R.T . ELECTRONICS I»TY . LTD-
Replacement Parts List 802995 VIDEODISTRIBUTIONAMPLIFIER VA-100NC
Page 2 of4
1 Part No.
SFR16T-100K
SFR16T-270K
RMF255-3M3
RMF251-75R
ASW-2-6R8
WA2G024S251U
3329H-101
3329H-102
CC4P7
CC8P2
CC47P
CC100P
CC120P
CC150P
CC390P
CC10N
CC22N
CC47N
CC100N
CP10N/63V
TT1/35
TT22/16
RT47/63
RB220/16
TZ032070E
TZ03P600E
Description.
RESISTORMETALFILM .25W 5%
RESISTORMETALFILM .25W 5%
RESISTORMETALFILM .25W 5%
RESISTORMETALFILM .25W 1%
RESISTORWIREWOUND 2W
RESISTORVARIABLE 2 5 OR
RESISTORVARIABLE100R
RESISTORVARIABLE IK
CAPACITORCERAMIC 4 . 7pF
CAPACITORCERAMIC 8 . 2pF
CAPACITORCERAMIC 47pF
CAPACITORCERAMIC lOOpF
CAPACITORCERAMIC120pF
CAPACITORCERAMIC150pF
CAPACITORCERAMIC390pF
CAPACITORCERAMIC10nF
CAPACITORCERAMIC22nF
CAPACITORCERAMIC47nF
CAPACITORCERAMIC lOOnF (Z5U)
CAPACITOR POLY 10NF 63V
CAPACITOR TAG TANT luF/35V
CAPACITOR TAG TANT 22uF/16V
CAPACITORELECTRO47uF/63V
CAPACITORELECTRO220uF/16V
CAPACITORVARIABLE2-7pF (BLUE)
CAPACITORVARIABLE 10-60pF (BROWN)
Qty
1
1
1
6
1
2
1
2
1
1
1
3
4
2
1
5
1
1
7
2
2
7
1
1
2
3
Get Ref .
R44
R47
R45
R31-36
R73
RV2,5
RV3
RV1,4
C13
C4
C6
C9, 11,22
C7,14,15,20
C16,18
C8
CIO, 31,32, 33, 34
C24
C12
ClOO-103,106,107,110
C35,36
C26,29
C27, 30, 104, 108, 109, 111, 112
C37
Cl
C2,5
C17,19,21
Sup|
•
•
58:
58:
58:
92:
•
•
•
*
•
•
•
•
•
•
•
•
58:
58:
58:
58:
58:
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51:
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•
•
•
•
•
•
81:
81:
51:
51:
802995 17/10/91
IRT Communications
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.T - ELECTRONICS
Replacement PartsList 802995 VIDEODISTRIBUTIONAMPLIFIER VA-100NC Page 3 of4
! Part No.
1N4148
1N4004
BZT03C68
BZX79C15
LEDGN5MM
2N3904
2N3906
2N2222
2N2905
2N2907
2N4959
2N3866
7812
7912
CA3080
LM310N
UM915
IM-2 4.7
IM-2 10
IM-2 100
IM-2 150
26-4100-24P
1100-1-124-03
ZTMJB505
2270B
Description.
DIODE 75V 100mA
DIODEPOWER 1A
DIODEZENER 68V
DIODEZENER 15V
LED GREEN
HF TRANS TO-92 NPN
HF TRANSTO-92 PNP
HF TRANS TO- 18 NPN
HF TRANS TO-39 PNP
HF TRANS TO- 18 PNP
RF TRANS TO- 18 PNP
RF TRANSTO-39 NPN
1C REGULATOR 12V1A
1C REGULATOR -12V 1A
OPERATIONAL TRANS COND AMP
OP AMP BUFFER
DC/DC CONVERTER 48/2x15
INDUCTOR 4.7uH
INDUCTOR lOuH
INDUCTOR lOOuH
INDUCTOR 150uH
CONNECTOR 24PIN
PC HEADER
PC HEADER (GOLD)
SHORTINGLINKS 30u GOLD
HEAT SINK
Qty
5
1
1
1
2
8
2
1
1
1
2
1
1
1
1
1
1
5
3
1
1
1
.66
.12
1
2
Get Ref.
Dll-15
Dl
D2
D10
LD1,2
Ql,2,6,7,12,13,15,16
Qll,14
Q4
Q10
Q5
Q3,8
Q9
U5
U6
U3
U4
XI
L3-7
L9,10,ll
LI
L2
PL1
PL2,3
LK1
Sup!
•
•
*
•
81:
81:
51:
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97:
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99:
99:
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802995 17/10/91
IRT Communications
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- R.T ELECTRONICS . H.TD .
Replacement PartsList 802995 VIDEODISTRIBUTIONAMPLIFIER VA-100NCPage 4 of4
! Part No.
E803183
W3108T
L1426
20x5 .250
SL48
021-1220
040-1620
5022
801576
800028
800029
801775
SBV1700/14/16
SNU/0520/17/4
Description.
ESCUTCHEON
1C SOCKET 8 PIN
OPENFUSEHOLDER (PCB)
FUSE250mA
LED HOLDER
KNOBBLACKWITHLINE
CAP BLACKWITHLINE
CO-AXIALCABLE
HANDLE S/W
COVER S/W MODULE
FRAME S/W MODULE
SIDECOVER
BRASSSTUD
"U" NUTS
Qty
1
2
1
1
2
2
2
.3
1
1
1
1
1
1
Get Ref.
SupJ
62
99
1
62
99
1
1
1
1
802995 17/10/91
IRT Communications
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T*
m JL •
Replacement PartsList 801180 REARASSEMBLY RB-1N ISSUE 2 Page 1 of1
! Part No.
26-4200-24S
AC40334-A76-A14
25.106.0253
PC801957
PC801171
800319
800320
CAP SCREW 4BA
Description.
CONNECTOR 24PINS
CONNECTORCOAXIAL 1.5/6
TERMINALBLOCK
PCB I/P LOOP COMP
REAR PLATE RB-lN
CHASSISREARASSY S/W
SIDEPLATEREAR ASSY
SCREW ALLENHEAD 4BA BLK
Qty
1
8
1
1
i
1
1
2
Get Ref .
Jl
TB1
LI
Sup|
*
*
54:
86:
61:
68:
26:
26:
26:
4 :
80118017/11/87
IRT Communications
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