Rixon LDM710 Modem

The Rixon LDM710 Limited Distance Modem is a copper-line data modem designed for long-reach links between sites over two- or four-wire metallic circuits. In point-to-point or multipoint configurations, it supports asynchronous transmissions up to 9,600 bits per second and can operate in half- or full-duplex mode, enabling flexible communications over copper lines. It is rated for distances up to 24.5 miles on AWG copper, making it suitable for connecting distant facilities without digital leased lines, and catalog listings identify an LDM710-L1 variant. Documentation from the era notes compatibility with Bell System references, specifically AT&T Tech Ref Pub 43401, underscoring its role as a standalone modem rather than an integrated data terminal. The LDM710 is part of Rixon’s historical line of modems, reflecting late-20th-century copper-based data communications technology for remote serial links.