PairGain 150-1141-05, Manual, Page: 10 / 78

Overview 150-388-105-05, Revision 05
2 March 25, 2000 HLU-388 List 5
C
OMPATIBILITY
The HLU-388 List 5 is designed to mount in DDM+ T1 repeater shelves. For a list of compatible shelves, see
“Appendix C - Compatibility” on page 63 .
All generations of HiGain HLU and HRU modules are compatible with each other. To take advantage of the
enhanced features of newer HiGain doublers, refer to
“HiGain Doubler Circuit Deployment” on page 63 .
A
PPLICATIONS
HiGain systems provide a cost-effective, easy-to-deploy method for delivering T1 High Capacity Digital Service
(HCDS) over metallic pairs.
• The service is deployed over two unconditioned, non-loaded copper pairs, yet it demonstrates a quality that
is competitive with fiber optics.
• Conventional, in-line, T1 repeaters are not required.
• Cable pair conditioning, pair separation, and bridged tap removal are not required.
Each loop has no more than 35 dB of loss at 196 kHz, with driving and terminating impedances of 135
Ω
.
Table 1 provides a loss guide for the various cable gauges at 196 kHz and 135
Ω
. The table applies to the HDSL
cable pairs between the HLU, HRU, and HDU modules. In the absence of specific insertion loss measurement
data, add 3 dB for each bridged tap and 1 dB for each cable gauge change.
Table 1. HDSL Loss Over Cables
Cable Gauge
(AWG/mm) Loop Loss at
196 kHz (dB/kft) Loop Resistance
(
Ω
per kft)
26 / 0.4 3.88 83
24 / 0.51 2.84 52
22 / 0.61 2.18 32
19 / 0.91 1.54 16