Quantum DLT 2000 Handbook page 56

up applications. In this chapter, we will take a look at the DLTtape
system features that make it the most reliable mid-range backup
system on the market today.
Unlike drives based on consumer video or audio recording tech-
nology, such as 8mm and DAT, DLTtape systems were designed
from the start for intensive data storage use in mid-range and high
end environments. DLTtape drive components and media work in
harmony to provide the fastest, most reliable, highest capacity tape
drives in the industry.
The following paragraphs outline the characteristics that give the
DLTtape system the reliability edge over all mid-range competitors.
Head Guide Assembly
DLTtape system reliability begins with a solid foundation: the head
guide assembly (HGA; see Figure 5-1). The patented DLTtape head
guide is a boomerang-shaped aluminum plate. In the DLT 4000,
DLT 7000, and DLT 8000 drives, it has six large bearing-mounted
rollers. These rollers are free-wheeling guides, with the last roller
acting as both a guide and a digital tachometer. The tachometer
controls the system's two drive motors to regulate tape position,
speed and tension. The Super DLTtape drives have four rollers
(see Figure 5-2).
The DLTtape head guide provides a rock solid path for the DLTtape
media to follow. The precise head/tape alignment achieved at the
factory is maintained by the HGA. Other tape drives, particularly
helical scan systems like the 8mm drive, have a much longer and
more complex tape path than the DLTtape system. A helical scan
system must pull its tape out of the cartridge and nearly all the way
around a cylindrical head. In addition, the tape path rollers used on
helical scan systems are small and result in acute tape wrap angles
5.2 RELIABILITY: THE HEART OF THE DLTtape SYSTEM