IRT VA-700 Скачать руководство пользователя страница 17

 

CVA-3120

 

 

VA-700 

I.R.T. Communications Pty Ltd | www.irtcommunications.com 

 

 

Page 17 of 23

 

Revision 10 

REMOTE GAIN CONTROL SUB-MODULE

 

 

(NOTE: Obsolete – No Longer Available. Information for existing modules only) 

 

GENERAL DESCRIPTION

 

 

 
The  CVA-3120  is  a  video  gain  sub-module  designed  to  be  fitted  to  the  IRT  VA-700  general  purpose  video 
distribution amplifier to provide remote access to the gain of the VDA. 
 
The  control  signal  is  completely  separate  to  the  video  path  and  so  does  not  cause  noise  in  the  video  path.  The 
control signal is damped to prevent noise on the external control causing short term gain variations. 
 
Control may be by either a DC control signal or via a simple potentiometer connected to the VDA. This makes the 
control suitable for both direct manual use or for operation at remote locations using other methods to generate 
the required DC control voltage. 
 
The high performance of the sub-board results in no significant degradation in the performance of the VDA. 
 

Standard Features: 

 

Fits standard VA-700 Eurocard VDA. 

 

Gain range 

±

3 dB. 

 

Noise free remote control via DC level. 

 

Control by potentiometer or DC input. 

 
Applications: 

 

Centralised control for fast set-up of levels in: 

 

O.B. vans. 

 

Master control. 

 

Camera gain matching. 

 

CVA-3120 Sub-module

DC gain

controlled

amplifier

2

3

1

+12 Vdc

1 KOhm

0 to + 12 Vdc

Buffer amplifier

Input from

VA-700

VDA

input

stage

Output to

VA-700

VDA

output

stage

Содержание VA-700

Страница 1: ...VA 700 I R T Communications Pty Ltd www irtcommunications com Revision 10 Analogue Video Distribution Amplifier User Manual...

Страница 2: ...handle omitted S N 9500000 04 27 11 1996 AJP CVA 3120 sub document included S N 9500000 05 12 01 2001 AL IRT Border page added for PDF format 00COMMON doc file contents added S N 9500000 06 05 07 2002...

Страница 3: ...es only 11 DL 700 Delay filter sub module 11 General Description 11 Technical Specifications 12 Configuration 13 Installation 13 AVD 3120 Video sync failure detector 14 General Description 14 Technica...

Страница 4: ...onditions dangerous potentials may exist in some circuits when power controls are in the OFF position Maintenance personnel should observe all safety regulations Do not make any adjustments inside equ...

Страница 5: ...RGB signal situations The video gain may be varied by 3 dB from the front panel Internal preset controls allow adjustment of the amplifier frequency response optimisation of the longitudinal hum rejec...

Страница 6: ...ential gain 0 1 at 4 43 MHz 12 5 87 5 APL Differential phase 0 1 at 4 43 MHz 12 5 87 5 APL Noise 70 dB unweighted Cross talk 75 dB between modules Transit time 22 at 4 43 MHz Cable Equalisation Up to...

Страница 7: ...e using the VA 700 to distribute pulses or sub carrier the clamp feature should be disabled LK 1 installed otherwise LK 1 should be removed External clamp reference An external video signal can be use...

Страница 8: ...s of the R 70 position the R 71 position and the rear pad of the R 80 position The external clamp reference from the GREEN VDA can be looped through from output connector 10 on the GREEN VDA to output...

Страница 9: ...ge specified Earthing The earth path is dependent on the type of frame selected In every case particular care should be taken to ensure that the frame is connected to earth for safety reasons See fram...

Страница 10: ...VA 700 I R T Communications Pty Ltd www irtcommunications com Page 10 of 23 Revision 10 Front rear panel connector diagrams O P 1 O P 3 LOOPED I P O P 9 O P 5 O P 7 O P 2 O P 4 I P O P 10 O P 6 O P 8...

Страница 11: ...the delay when in operating configuration The DL 700 provides two sockets for fitting DIL delay lines or filters one of up to 40 pins and one of up to 48 pins Pins normally used for grounding connect...

Страница 12: ...fier only Input Type DC coupled Impedance 75 Maximum Level 2 V p p 0 dB gain Output Type DC coupled Impedance 75 source terminated Gain 3 dB Adjustable by fitting programming resistor Power requiremen...

Страница 13: ...supporting VDA Variable delay To configure the variable delay section use the link pads located near SK 2 Enable Connect LK 1 LK 2 and LK 3 LK 4 Disable Connect LK 2 LK 3 and cut links LK 1 LK 2 and L...

Страница 14: ...tribution amplifier for indicating loss of incoming video signals to the VDA An LED is fitted to the sub module which extends through the front panel of the VA 700 and a relay closure alarm output is...

Страница 15: ...s after sync loss Alarm reset 800 ms after sync return Indicators alarms Visual indicators VIDEO FAIL ALARM LED Alarm output Relay circuits operated from alarm logic Changeover relay contact set Relay...

Страница 16: ...the VDA in order to fit the AVD 3120 and the performance of the VDA will not be affected by the inclusion of the AVD 3120 AVD 3120 If a second equaliser sub module is fitted to the VA 700 as is the c...

Страница 17: ...n variations Control may be by either a DC control signal or via a simple potentiometer connected to the VDA This makes the control suitable for both direct manual use or for operation at remote locat...

Страница 18: ...emote control connector on rear panel of VA 700 DC 0 12 Vdc connected to pin 3 of 3 pin remote control connector pin 1 Gnd on rear panel of VA 700 Response time constant 0 1 seconds Power Requirements...

Страница 19: ...N Where VO is the output voltage and VIN is the video input signal Maximum attenuation If greater attenuation is required the value of R 2 may be adjusted to provide the necessary gain range Please no...

Страница 20: ...o remote connection on rear assembly using the three pin IDC socket provided The remote gain control potentiometer should be wired as follows Gain adjustment Under normal circumstances no adjustments...

Страница 21: ...provided Standard EQ 1227 equaliser sub module Optional Instruction manual included in VA 700 VA 700T manual TS01ABE tiny slide switch for mounting on VA 700 PCB to switch between EQ 1227 and VA 700 i...

Страница 22: ...iser and position 2 to the EQ 1227 equaliser If only EQ 1227 equalisation is to be required the PCB track connecting one side of switch SW 1 should be cut and a link soldered between the centre contac...

Страница 23: ...Warranty on components shall be extended by IRT only to the extent obtainable from the component supplier Equipment return Before arranging service ensure that the fault is in the unit to be serviced...

Отзывы: