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MHX-920 Operating Manual: Chapter3 Installation

 

3

 

3. Installation 

 

 

 

 
 

 

 

3.0

 

Overview 

Qualified and experienced personnel must carry out the 
installation, removal or maintenance of all antenna 
components. 

The N2420B complies with FCC part 15 at the modular level for operation 
in the license-free 2400-2483.5 MHz ISM band.  This chapter provides 
guidelines for installing and deploying equipment which incorporates the 
N2420B module. 

3.1

 

Estimating the Gain Margin 

Successful communication between N2420B modules is dependent on three 
main factors: 

 

System Gain 

 

Path Loss 

 

Interference 

System gain is a calculation in dB describing the performance to be 
expected between a transmitter-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) 

2.

 

Transmitter gain (transmitting antenna gain minus cabling loss between 
the transmitting antenna and the N2420B module) 

3.

 

Receiver gain (Receiving antenna gain minus cabling loss between the 
receiving antenna and the module) 

4.

 

Receiver sensitivity (Specified as -108dBm on the N2420B module) 

In the following illustration, the transmitting antenna has a gain of 6 dB, 
and the receiving antenna has a gain of 3 dB.  The cable loss between the 
module and the antenna is 2 dB on both the transmitting and receiving side. 

 

 

 

 

 

 

Transmitter

30 dBm

Output Power

Receiver

Sensitivity =

-105 dBm

Cable Loss = 2 dB

Cable Loss = 2 dB

Antenna Gain = 6 dB

Antenna Gain = 3 dB

Summary of Contents for n2420B

Page 1: ...Operating Manual n2420B 2400 MHz Spread Spectrum OEM Transceiver Revision 0 60 August 16 2011 Phone 403 248 0028 Fax 403 248 2762 www microhardcorp com Model N2420B Microhard Systems Inc ...

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 corporations or affiliates shall be released and discharged from any and all manner of action causes of action liability losses damages suits dues sums of money expenses including legal fees general damages spe...

Page 3: ...ration of Conformity procedure without a transmitter certified module and a module is added the host manufacturer is responsible for ensuring that the after the module is installed and operational the host continues to be compliant with the Part 15B unintentional radiator requirements Since this may depend on the details of how the module is integrated with the host the grantee the party responsib...

Page 4: ...tu de la Déclaration de la procédure de conformité sans un module émetteur et d un module certifié est ajouté le fabricant d hôte est responsable de s assurer que les fois que le module est installé et opérationnel de l hôte continue à être conforme à la partie 15B exigences rayonnement non intentionnel Depuis cela peut dépendre des détails sur la façon dont le module est intégré avec l hôte le bé...

Page 5: ...ected Consult the dealer or an experienced radio TV technician for help FCC Avis utilisateur Sec 15 105 REMARQUE Cet équipement a été testé et trouvé conforme aux limites pour un appareil numérique de classe B conformément à la partie 15 des règlements de la FCC Ces limites sont conçues pour fournir une protection raisonnable contre les interférences nuisibles dans une installation résidentielle C...

Page 6: ...Rights ii N2420B Regulatory Requirements iii CONTENTS VI 2 GENERAL 1 2 0 PRODUCT OVERVIEW 1 2 1 OUTPUT POWER LEVEL 2 3 INSTALLATION 3 3 0 OVERVIEW 3 3 1 ESTIMATING THE GAIN MARGIN 3 3 2 ANTENNAS AND CABLING 5 3 2 1 Internal Cabling 5 3 2 2 Installing External Cables Antennas and Lightning Arrestors 6 ...

Page 7: ...pectrum1 this means that it can be used without access fees such as those incurred by cellular airtime a serial I O data port with handshaking and hardware flow control allowing the N2420B to interface directly to any equipment with an asynchronous serial interface ease of installation and use the N2420B module uses a subset of standard AT style commands very similar to those used by traditional t...

Page 8: ...power levels so it is recommended that the lowest power necessary is used using excessive power contributes to unnecessary RF pollution 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 set...

Page 9: ...between a transmitter 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 2 Transmitter gain transmitting antenna gain minus cabling loss between the transmitting antenna and the N2420B module 3 Receiver gain Receiving antenna gain minus cabling loss between th...

Page 10: ...ween system gain and path loss Referring to the same example suppose the path loss is 100 dB the gain margin would be 40 dB which is more than adequate 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 path loss numbers for varying antenna heights and antenna ...

Page 11: ... procedure for installing cabling and antennas for use with the N2420B module 3 2 1 Internal Cabling The most common method for installing the module is to run a cable from the module 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 losses are negligi...

Page 12: ...stors The most effective protection against lightning is to install two lightning surge arrestors one at the antenna the other one at the interface with the equipment The surge arrestor grounding system should be fully interconnected with the transmission tower and power grounding systems to form a single fully integrated ground circuit Typically both ports on surge arrestors are N female External...

Page 13: ...quipment If the equipment is in a fixed location and is to communicate with only one other unit also in a fixed location then a Yagi antenna is suitable Choose a Yagi with enough gain to ensure adequate gain margin When deploying the Yagi point the antenna towards the intended target ensuring the antenna elements are perpendicular to the ground for vertical polarization In applications where there...

Page 14: ...em to the maximum power setting of 30dBm Example 2 What is the maximum power the N2420B can be set to comply with FCC and IC given the following equipment given a Yagi Ant Gain 12dBd and cable and connector loss of 4 5 dB Max EIRP 36dBm Max TX power EIRP Ant Gain dBi Cable Connector loss dB Ant Gain dBi Ant Gain dBd 2 15 dB Yagi Gain dBi 12 2 15 14 15dBi Max TX power 36dBm 14 15dB 4 5dB 26 35dBm W...

Page 15: ... Microhard Systems Inc could void the user s authority to operate the equipment This device has been tested with MMCX and Reverse Polarity SMA connectors with the antennas listed in Appendix A When integrated in OEM products fixed antennas require installation preventing end users from replacing them with non approved antennas Antennas not listed in the tables must be tested to comply with FCC Sec...

Page 16: ...e d antenne et son gain de sorte que la puissance isotrope rayonnée équivalente p i r e ne dépasse pas l intensité nécessaire à l établissement d une communication satisfaisante Le présent émetteur radio IC 3143A 11P31 a été approuvé par Industrie Canada pour fonctionner avec les types d antenne énumérés ci dessous et ayant un gain admissible maximal et l impédance requise pour chaque type d anten...

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