HR
X
-C-HB-3
V
IA
L
ITE
HD
C-B
AND
L
INK
H
ANDBOOK
19
3
External Feed from chassis connector 0 to +28V at 350mA
5
Internally gen13.4 ± 1 or +18.5 ± 1 selectable 350mA (up to 7.1GHz)
L
Internally gen13.4 ± 1 or +18.5 ± 1 selectable 700mA (up to 6.0GHz)
2.5.7
Manual configuration of LNA/LNB and BUC feeds, plug-in modules
Some modules can be configured either by jumper or by switch to provide an LNA/LNB or BUC feed
either from an internally generated voltage or from the rear connector in the
ViaLiteHD
chassis. The
diagram below shows how these are set.
Units with LNA/ LNB internal power supplies (options 1, 2, and 5)
will be delivered set to “internal”.
Units with external LNA power (option 3) will be set to “external”. Units with no LNA/LNB or BUC feed
(option 0) will normally have no headers fitted to positions J15 or J16.
Manual configuration of LNA/LNB/BUC DC power feeds
2.6
Module Interface ratings
2.6.1
Susceptibility to DC pulses from ViaLiteHD receivers
All receiver modules will create a 1-
2Vpeak DC transient from the RF output at start up into a 50Ω
load (approximately 5V into a 1MΩ load). This may cause failure in some very sensitive spectrum
analysers or similar equipment. Please check before connecting your equipment. Contact
ViaLite
Communications
for more details.
2.6.2
Protection of ViaLiteHD equipment from DC pulses
All modules have AC coupled inputs and/or outputs and will be sensitive to large transients (>5V)
applied at the RF connector. This may result in permanent damage to the modules, particularly to low
frequency or wideband modules. DVB-T and L-Band HTS modules are designed to survive non
repetitive DC pulse of up to 36V. To increase protection, BUC feed option “B” can be specified for
GPS receiver modules to increases their robustness to DC pulses see section 2.5.6. Contact
ViaLite
Communications
for more details.
2.6.3
Logic interface, TTL 5V
Absolute maximum voltage rating
-0.5 to +5.5V
No damage
Input, Logic Low (max)
<0.8V
Input, Logic High (min)
>2.0V
Output, Logic Low (max)
<0.4V no load
TX
J4 (LNB)
up = external
down = internal
open = not connected
RX
up =
J10
(
BUC)
up = external
down = internal
open = not connected
