User's Manual

ARCell IF cables
(3 downstream + 6 Upstream)
Lightning protectors
for ARCell IF cables
Figure 5-11: Details of Fig 5-10 IF cable protection.
5.3.2 DC Power
The Hub Transceiver requires 8.0 – 8.5 Vdc at the transceiver modules and draws
approximately 900 mA of current.
In a one or two sector installation a small variable voltage linear DC power supply capable of
supplying at least 1000 mA is employed. Arcwave has successfully tested the following power
supply in a one or two sector configuration:
Agilent model E3610A
The voltage (IR) drop of the power cable is calculated and the output of the DC supply is set
appropriately.
In a multi-sector installation the DC power supply is chosen with sufficient capacity to deliver at
least 1000 mA for each Hub Transceiver. The DC+ lead is sized to provide reasonable voltage
drop between the DC supply and the Outdoor Junction Box (OJB) installed near the Hub
Transceivers. [It is the installer’s responsibility to furnish, assemble and install the OJB].
The DC power supply is then adjusted to provide 8.0 – 8.5 Vdc at the Transceiver connector.
A power supply with an ammeter is a great help when trouble-shooting a Hub since experience
has shown that a bad transmitter or receiver module may be “dead” or it may be drawing half its
normal current. In either case it is usually very noticeable.
5.3.3 Transmit (Downstream) Signal Path
In the BSR1000W the Downstream upconverter is internal, and the output level can be set via
the command line interface or network management software.
In the V3000W, the downstream signal is connected to the external upconverter (normally
mounted in the rack with the W-CMTS). A 10 dB pad is inserted at the input to the upconverter
to set the proper level.
June 2003 Page 5-11