Black Box ME759C-RJ11, May-95 Appendix Cable Recommendations, Wire Gauge Capacitance Resistance

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	Ω/1000 ft. (53.5 Ω/km)
22 AWG	83 nf/mi. or 15.72 pf/ft.*	32.6	Ω/1000 ft. (107 Ω/km)
24 AWG	83 nf/mi. or 15.72 pf/ft.*	51.65 Ω/1000 ft. (169.5 Ω/km)
26 AWG	83 nf/mi. or 15.72 pf/ft.*	82.35 Ω/1000 ft. (270.2 Ω/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.

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