Product manual

XStream-PKG-R™ RS-232/485 RF Modem Product Manual v4.2B5
Antennas
(Refer to Appendix A for a list of FCC-Approved Antennas)
Factors that determine wireless link range:
Ambient RF noise (interference)
Line-of-sight obstructions
Transmit power
Receive sensitivity
Antenna configuration
XStream Antenna Connector Options
To comply with the FCC rules and obtain a “modular” certification, it is required that XStream
Modems utilize a “non-standard” connector. This is to ensure the modems are used only with
approved antennas.
RPSMA
The Reverse Polarity SMA (RPSMA) connector uses the same body as
a regular SMA connector. In order to be a “non standard” connector,
the gender of the center conductor is changed. The female RPSMA
actually has a male center conductor.
Antenna Cables
RF cables are typically used to connect a radio installed in a cabinet to an antenna mounted
externally. As a general rule, it is best to keep the RF cable as short as possible. All cables
promote signal loss which is usually measured in dB loss per 100 ft. Digi provides LMR-195 rated
cables. Common cables and dB losses are included in this table:
Table B.2. Potential Signal Strength Loss due to Antenna Cable Length
Cable
Type
Loss at 900 MHz per 100’
(loss per 100m)
Loss at 2.4 GHz per 100’
(loss per 100m)
Diameter
RG-58
14.5 dB (47.4 dB)
25.3 dB (83.2 dB)
0.20” (4.95 mm)
RG-174
25.9 dB (85.0 dB)
44.4 dB (145.8 dB)
0.10” (2.54 mm)
RG-316
24.7 dB (81.0 dB)
42.4 dB (139.0 dB)
0.10” (2.59 mm)
LMR-195
11.1 dB (36.5 dB)
19.0 dB (62.4 dB)
0.20” (4.95 mm)
LMR-240
7.6 dB (24.8 dB)
12.9 dB (42.4 dB)
0.24“ (6.10 mm)
LMR-600
2.5 dB (8.2 dB)
4.4 dB (14.5 dB)
0.59” (15.0 mm)
© 2014 Digi International Inc. 42