DV/IP digital radio systems may be interfaced to existing analog radio systems. This makes it possible to selectively "cross patch" communications from legacy FM systems to digital DV/IP systems. DWC's DC-500 Analog Repeater Digital Gateway allows DV/IP digital radios to control FM repeaters, SSB radios, AM aircraft radios, paging systems, and many other communications devices.

Using the same DV/IP digital protocol used in DWC's mobile, portable and base station radios, the DC-500 connects to an analog mobile (or control station) radio or a base station repeater. The DC-500 provides transmit audio and PTT to the analog radio, and digitally encodes receive audio from the analog station. It uses COR from the analog station to initiate digital transmissions.

The DC-500 connects to a DV/IP network through a rear-panel RJ-45 Ethernet connector using TCP/IP protocol. Consequently the DC-500 may be located anywhere in the world where the Internet (or a private Intranet) is available, and communications linked to the DV/IP system. Two or more DC-500s may be used to link two or more analog repeaters into a wide area network.

The DC-500 is programmed to become a "phantom" mobile unit on a DV/IP digital network, with an individual unit ID, as well as group and fleet IDs. Consequently, a DC-500 (and consequently an analog FM channel) may be assigned as a group on a DV/IP digital system, allowing DV/IP radios to selectively access the analog system.

Typical applications include cross patching of an analog channel to a digital group during transition from analog to digital communications, interoperability between a modern DV/IP system and one or more analog channels, monitoring of a remote audio source, such as an off-air receiver or security microphones, and selectable access to an in-plant or campus public address system.

Analog receive audio is compressed and limited to compensate for poor audio quality typical of analog systems. The unit can be programmed to interface using either "active high" or "active low" PTT and COR. The unit's low impedance 600 ohm audio output may be connected to almost any mobile radio or repeater, and both low and high impedance inputs are available for receive audio. A band pass filter cleans up analog receive audio and eliminates low frequency coded squelch.

The DC-500 is powered from an externally provided 13.6 VDC, is constructed in a 19" rack-mounted, industrial grade chassis 1.75 inches high. It features a front panel vacuum flourescent display. The display provides a maintenance technician with operation and test information. The unit is programmed through a rear panel technican test connector.

An standard cable is available that connects a DC-500 to a low cost Motorola 1225 mobile radio on a plug-in basis.