34
APPENDIX B
CABLE RECOMMENDATIONS
All Patton Electronics Company Short Range Modems are tested to the
distances published in our Catalogs and Specification Sheets on twisted-
pair cable with the following characteristics:
We fully expect that the Short Range Modems will operate on lines with
specifications different from those tested, but to reduce the potential diffi-
culties in the field, one should ensure that the cable being used has sim-
ilar or better characteristics (lower capacitance or lower resistance).
Wire with capacitance of 20pF/ft. or less is suitable for all our Short
Range Modems however, distances may vary from those published in
our catalog. Resistance will also affect distance but not functionality.
Wire should be 26 AWG or larger (smaller AWG#).
Patton products are designed to withstand normal environmental noise
and conditions however, other environmental factors too numerous to
discuss in this format may affect proper operation of the SRM’s.
Wire Gauge
Capacitance
Resistance
19 AWG
83nF/mi or 15.72 pF/ft.
.0163 ft.
22 AWG
83nF/mi or 15.72 pF/ft.
.0326 ft.
24 AWG
83nF/mi or 15.72 pF/ft.
.05165 ft.
26 AWG
83nF/mi or 15.72 pF/ft.
.08235 ft.
Model 1080A Distance Table (miles)
Wire Gauge
Data Rate
19
22
24
26
57,600
12
7.0
5.3
4.0
38,400
13
7.5
6.2
4.2
28,800
14
8.0
6.6
4.6
19,200
16
8.5
7.0
5.1
14,400
17
11.0
9.2
6.5
9,600
18.5
13.0
10.4
7.5
7,200
19.0
13.5
10.9
8.0
4,800
19.5
14.0
11.3
8.8
3,600
20
14.5
11.5
8.8
2,400
20.5
15.0
11.6
9.0
1,800
20.5
15.0
11.5
8.9
1,200
20
15.0
11.4
8.9
