What is System Fusion?
System Fusion is a protocol developed by Yaesu for digital communications. When you transmit in one of the digital modes, your signal is sent over the air as a digital bit stream, to be decoded by the radio at the other end. A part of the bit stream is embedded error correction and detection, so that even very weak signal may sound crystal clear.

What modes does a System Fusion radio support?
FM - The current radios support standard FM, as is used on the majority of Amateur Radios in service today. They also support narrowband FM, as is now required in the commercial service in the USA and other locations.
DN - Digital Narrow is a digital mode that supports voice and data. When in the DN mode, the transmitters can include position location, similar to APRS at the same time as voice.
VW - Voice Wide supports only voice. It's advantage is that it is excellent voice quality, some think that it's much better than FM.
DW - The radios use the data mode to transmit pictures. In this mode, the entire bandwidth is used as data to provide the quickest transmission.

How does System Fusion sound?
It actually sounds pretty great, especially in the VW mode. But in a recent test, where FM, DN, and DSW were compared, most people thought that DN sounded better than FM. When you are listening to either of the digital signals, you don't hear any hiss. It's much more pleasant to listen to.
The Repeater
The DR-1 is Yaesu's repeater for System Fusion. The repeater support 144 and 440 MHz and is self-contained, except for the duplexer. The repeater is quite flexible in it's capabilities. want 2M in and 440 out. or maybe FM or Digital in and FM out. It supports most combinations that you can think of. The repeater can quickly and easily replace most existing repeaters and provides a plug and play operation.
Lakeway Area Fusion Repeaters
The Lakeway Amateur Radio Club has purchased two DR-1 repeaters to replace existing repeaters on Clinch Mountain on the existing frequencies of 147.030/630 MHz and 443.450/449.450 MHZ.  The Lakeway Digital Group has purchased two DR-1 repeaters to be place on Short Mountain to go on frequencies 147.390/990 MHz and 444.975/449.975 MHz.  The W4LDG machines are planed to be linked with other machines in upper and lower east Tennessee.  The site will also host the W4LDG DSTAR repeaters on 144.920/147.42 MHz and 444.475/449.475 MHz and an Echolink repeater on the VHF band. 
Invitation to the Future - is an eight page brochure that list the current Yaesu Digital products and their features.  It also discusses the choice of C4FM Digital mode and the use of both analog and digital modes at the same time.  The brochure gives the reader good basic understanding on the technology and the products avaliable for use in the SystemFusion program.  Click here to view or print a copy.