VA-700
I.R.T. Communications Pty Ltd | www.irtcommunications.com
Page 5 of 23
Revision 10
GENERAL DESCRIPTION
The VA-700 is a video distribution amplifier of modular Eurocard construction having facilities for cable
equalisation, longitudinal hum reduction, and clamping.
The input is a bridging loop through type to facilitate connection to other equipment. Ten 75
Ω
outputs are
provided on the rear with an additional output on the front panel for ease of monitoring.
The input and output grounds are separated to provide rejection of longitudinally developed hum. The input is AC
coupled and the output DC restored with options for no clamping or clamping to the internal or an external signal.
The external clamping facility may be used to provide correct DC restoration in YUV & 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 rejection, and stage output DC voltages.
Cable equalisation is provided for up to 300 metres of 75
Ω
high quality cable with adjustment via the front panel.
The VA-700 may also be used as a pulse distribution amplifier. (Only 6 outputs may be used for 4 Vp-p)
The VA-700 is manufactured on an extended Eurocard board for mounting in IRT Eurocard frames.
Standard features:
•
IRT Eurocard construction
•
Loop through input
•
Ten BNC outputs on rear
•
>30 MHz bandwidth
•
Front panel monitoring output
•
Cable equalisation to 300 metres
•
Various clamping options
•
Longitudinal hum stripping
•
Front panel EQ & gain adjustment
BLOCK DIAGRAM VA-700 SIGNAL PATH
CABLE
EQUALISATION
& HUM
REJECTION
VDA
+ DC OFFSET
O/P 1
O/P 2
O/P 3
O/P 4
O/P 5
O/P 6
O/P 7
O/P 8
O/P 9
O/P 10
MON O/P
ANALOGUE
VIDEO I/P
CLAMPING
CCT