Black Box May-95 Cable Box User Manual


 
37
APPENDIX: Cable Recommendations
Appendix: Cable Recommendations
The Multi-Function LD Card has been performance-tested using twisted-pair
cable with these characteristics:
Wire Gauge Capacitance Resistance
19 AWG 83 nf/mi. or 15.72 pf/ft.* 16.3 /1000 ft. (53.5 /km)
22 AWG 83 nf/mi. or 15.72 pf/ft.* 32.6 /1000 ft. (107 /km)
24 AWG 83 nf/mi. or 15.72 pf/ft.* 51.65 /1000 ft. (169.5 /km)
26 AWG 83 nf/mi. or 15.72 pf/ft.* 82.35 /1000 ft. (270.2 /km)
*Alternatively, 51.6 nf/km or 51.6 pf/m
If you use the Multi-Function LD Card with a different type of twisted-pair
cable, make sure that the cable has characteristics similar to, or better than,
those listed above (for example, lower capacitance or lower resistance).
Bench tests yield the following data-rate/maximum-distance results:
Data Rate Maximum Distance in miles (km)
in bps 19 AWG 22 AWG 24 AWG 26 AWG
57,600 12 (19.3) 7 (11.3) 5.3 (8.5) 4 (6.4)
38,400 13 (20.9) 7.5 (12.1) 6.2 (10) 4.2 (6.8)
28,800 14 (22.5) 8 (12.9) 6.6 (10.6) 4.6 (7.4)
19,200 16 (25.7) 8.5 (13.7) 7 (11.3) 5.1 (8.2)
14,400 17 (27.4) 11 (17.7) 9.2 (14.8) 6.5 (10.5)
9600 18.5 (29.8) 13 (20.9) 10.4 (16.7) 7.5 (12.1)
7200 19 (30.6) 13.5 (21.7) 10.9 (17.5) 8 (12.9)
4800 19.5 (31.4) 14 (22.5) 11.3 (18.2) 8.8 (14.2)
3600 20 (32.2) 14.5 (23.3) 11.5 (18.5) 8.8 (14.2)
2400 20.5 (33) 15 (24.1) 11.6 (18.7) 9 (14.5)
1800 20.5 (33) 15 (24.1) 11.5 (18.5) 8.9 (14.3)
1200 20 (32.2) 15 (24.1) 11.4 (18.3) 8.9 (14.3)
Many environmental factors can affect the maximum distances obtainable at a particular
site. Use this table as a general guideline only.