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RF401-series and RF430-series Spread

Spectrum Radio/Modems

1. Introduction

This manual discusses the RF401-series and RF430-series spread spectrum

radios. Spread spectrum radios spread the normally narrowband information

signal over a relatively wide band of frequencies. This allows the

communications to be more immune to noise and interference from RF sources

such as pagers, cellular phones and multipath. The RF401-series and RF430-

series radios reduce susceptibility to RF interference from other spread

spectrum devices by providing user-selectable frequency hopping patterns.

You do not need a communications authority license for the

RF401-series or RF430-series configurations described in this

manual including U.S. Government Agencies regulated by NTIA

Annex K. Spread spectrum radios, like all FCC Part 15 devices,

are not allowed to cause harmful interference to licensed radio

communications and must accept any interference that they

receive. Most Campbell Scientific users operate in open or

remote locations where interference is unlikely. If there is a

problem, interference can be reduced using methods such as

moving the device, reorienting or using a different type of

antenna, or adding RF shielding.

NOTE

The RF401-series and RF430-series radios can provide up to one mile

transmission range when using an inexpensive whip antenna. The radios can

provide up to 10 mile transmission range when using a higher gain directional

antenna at ideal conditions. Compatible antennas are described in Section 4.4.

Line-of-sight obstructions and RF interference will affect the

transmission distance. See Appendix H for a discussion of

antenna gain and other factors affecting distance.

NOTE

You may test the radio communications onsite by using the 21107 900 MHz

Spread Spectrum Demo Kit; contact Campbell Scientific for more information.

Campbell Scientific does not recommend using RF401-

series and RF430-series radios in networks containing

RF450 radios. The RF450 radios will interfere with the

transmission of the RF401-series and RF430-series radios.

CAUTION

1.1 RF401-series Radios

The RF401-series radios have a CS I/O port and an RS-232 port (see Figure 1).

These radios can serve as a field modem/radio while connected to the

datalogger or as a base station modem/radio when connected to a PC’s RS-232

port. The following models are available:

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Campbell RF400 Manual Pagina 13