User's Manual

ADCP-75-348 • Issue 1 • 04/2008

Page 5

• Converts incoming digital signal to analog, filters, amplifies and up-converts

• Provides bi-directional interface between parallel digital RF (to D/A and from A/D) and

Serial RF (SeRF) to/from SeRF board

• Performs digital up/down conversion and adjustable delay processing

• Non-contiguous bands and receive diversity is implemented with multiple DART Cards

3.3.1 RF Signal Connections

The RF signal connections between the HU DART cards and the BTS are supported through

two (FWD RF IN and REV RF OUT) QMA-Type female connectors. One connector is used for

the forward path RF signal. The other connector is used for the reverse path RF signal. In some

installations, it may be necessary to install a Conditioning Panel and/or Duplexing Panel

(accessory items) to support the interface between the HU and the BTS. The HU should be as

close as possible to the BTS to minimize cable losses.

3.4 System Card

The System Interface Card gives additional front panel space for the SeRF card. The System

Card front panel also provides connections for alarm outputs, 10 MHz output, and status LEDs.

This card may be used to provide a 10 MHz clock reference to which the SeRF's Master clock is

frequency locked from the internal crystal oscillator. When the internal clock is not used the

clock can be obtained from an external 10 MHz input.

3.5 Power Supply

HU is powered by a modular DC to DC power supply located on the lower left side of the

chassis. An On/Off switch is provided on the HU power supply module front panel.

HU is powered by ± 20 to ± 60 VDC power (nominal ± 24 or ± 48 VDC), power is fed to the HU

through a connector located on the front of the module. Power to the HU must be supplied

through a fuse panel (available separately). Each HU must be protected with a fuse.

3.6 User Interface

The HU user interface consists of the various connectors, switches, terminals, and LEDs that are

provided on the HU front panel. The HU user interface points are indicated in

Figure 4 and

described in Table 2.