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MHX 920 Operating Manual: Chapter 2 Configuration 

 

2. Configuration 

 

 

 

 

 

 

 

 

 

 

2.0

 

Overview 

This chapter provides a detailed description of the various operating 
parameters of the MHX-910A. 

2.1

 

Output Power Level 

The Output Power Level determines at what power the MHX-910A 
transmits. The MHX-910A’s sensitive receiver can operate with very low 
power levels, so it is recommended that the lowest power necessary is used; 
using excessive power contributes to unnecessary “RF pollution”. 

The allowable settings are: 

0 1 

mW 

1 10 

mW 

*2 100 mW 

3 1000 

mW 

Ideally, you should test the communications performance between units 
starting from a low power level and working upward until the RSSI is 
sufficiently high and a reliable link is established. The conditions will vary 
widely between applications; the output power settings can be calculated 
based on following information. 

 

Transmitter antenna gain 

 

Cable loss 

 

Effective radiated power (ERP) requirement by FCC Regulations 

Power Setting = 36 – Antenna Gain – Cable Loss 

The power setting must be no more than the above calculation value. Any 
higher is a violation of FCC rules. 

Summary of Contents for MHX-910A

Page 1: ...ual i Operating Manual MHX 910A 900 MHz Spread Spectrum OEM Module Revision 0 10 November 1 2004 17 2135 32nd Ave N E Calgary Alberta T2E 6Z3 Phone 403 248 0028 Fax 403 248 2762 www microhardcorp com...

Page 2: ...TIONAL WARRANTY Indemnification The Purchaser shall indemnify Microhard Systems Inc and its respective directors officers employees successors and assigns including any subsidiaries related corporatio...

Page 3: ...more information or would like to order an antenna WARNING MAXIMUM ERP FCC Regulations allow up to 36 dBm effective radiated power ERP Therefore the sum of the transmitted power in dBm the cabling lo...

Page 4: ......

Page 5: ...FIGURES VII 1 INTRODUCTION 1 1 0 PRODUCT OVERVIEW 1 1 1 FEATURES 2 2 CONFIGURATION 4 2 0 OVERVIEW 4 2 1 OUTPUT POWER LEVEL 4 3 INSTALLATION 7 3 0 OVERVIEW 7 3 1 ESTIMATING THE GAIN MARGIN 7 3 2 INTER...

Page 6: ......

Page 7: ...MHX 910A Operating Manual History v History Revision Date Action FW Rev Note 0 10 2004 11 01 Created For FCC Approval...

Page 8: ......

Page 9: ...Operating Manual Tables and Figures vii Tables and Figures Tables Table 1 Path Loss 8 Table 2 Cable Loss 10 Figures Figure 1 Gain Calculation 7 Figure 2 System Deploying 8 Figure 3 Suggested Internal...

Page 10: ......

Page 11: ...rformance of this product makes it ideal for many applications Typical uses for this module include SCADA Remote Telemetry Surveillance Traffic Control Industrial Controls Remote Monitoring Fleet Mana...

Page 12: ...aximum allowable transmit power 1W Low power consumption in Sleep Mode Real Time Clock wakeup 32 bit CRC selectable forward error correction with retransmission Separate diagnostics port transparent r...

Page 13: ...MHX 910A Operating Manual Chapter 1 Introduction 3...

Page 14: ...ecessary RF pollution The allowable settings are 0 1 mW 1 10 mW 2 100 mW 3 1000 mW Ideally you should test the communications performance between units starting from a low power level and working upwa...

Page 15: ...any user or member of the public IMPORTANT FCC Regulations allow up to 36 dBi effective radiated power ERP Therefore the sum of the transmitted power in dBm the cabling loss and the antenna gain cann...

Page 16: ......

Page 17: ...ter receiver pair The number can be calculated based on knowledge of the equipment being deployed The following four factors make up a system gain calculation 1 Transmitter power user selectable 0 20...

Page 18: ...equate for reliable communication Path loss is a very complicated calculation which mainly depends on the terrain profile and the height of the antennas off the ground The following table provides pat...

Page 19: ...s MCX connector to a reverse TNC bulkhead connector on the chassis of the equipment as shown in Figure 3 This cable can be purchased from Microhard Systems Figure 3 Suggested Internal Cabling Cable lo...

Page 20: ...MHX 910A equipment is powered down during installation At all time a distance of 23 cm must be maintained between the antenna and any person when the device is in operation Surge Arrestors The most ef...

Page 21: ...the antenna connector surge arrestor The cable must be supported at the top with a hose clamp or wrap lock and at 5 ft intervals down the length of the tower Over tightening the fasteners will dent th...

Page 22: ...ground for vertical polarization In applications where there are multiple units that you must communicate with or units which are in motion you may select an Omni directional antenna with appropriate...

Page 23: ...to the maximum power setting of 30dBm Example 2 What is the maximum power the MHX 910A can be set to comply with FCC and IC given the following equipment given a Yagi Antenna Gain 12dBd and cable and...

Page 24: ...14 MHX 920 Operating Manual Chapter 3 Installation...

Page 25: ...00MHz Yagi Directional Antenna Bluewave RPTNC Pigtail MHS031501 9dBd 900MHz Yagi Directional Antenna Antenex RPTNC Pigtail MHS031441 10dBd 900 MHz Yagi Directional Antenna Bluewave RPTNC Pigtail MHS03...

Page 26: ...16 MHX 910A Operating Manual Appendix A Approved Antennas...

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