E F Johnson Company 2422001-1 Benutzerhandbuch

2-1

August 2000

Part No. 001-2001-200

Information in this section tells how to set up the 

repeater for operation in an LTR system.  It is assumed 
that the repeater has been previously aligned at the 
factory or as described in the alignment procedure in 
Section 7.

Even though each repeater is thoroughly aligned 

and tested at the factory, it is good practice to check 
performance before it is placed in service.  This 
ensures that no damage occurred during shipment and 
that the repeater is otherwise operating properly.  Per-
formance testing is described in Sections 7.1, 7.2, 7.3 
and 7.4.

2.1.1  SITE PREPARATION AND ANTENNA IN-

STALLATION

Site preparation and antenna installation are not 

within the scope of this manual.  Basic installation 
requirements are discussed in the "Dealer Guide To 
Site Preparation", Part No. 004-8000-100.  Factory 
installation is also available.  Contact your Johnson 
representative for more information.

The following conditions should be considered 

when selecting a site for the Repeater.

Operating Temperature.

-30

°

C to +60

°

C (-22

°

F to +140

°

F).      

Humidity.

Less than 95% non-condensing relative humidity 

at 50

°

C.

Air Quality.

For equipment operating in a controlled environ-

ment with the Repeaters rack mounted, the airborne 
particles must not exceed 30 

µ

g/m

3

.

For equipment operating in an uncontrolled envi-

ronment with the Repeaters rack mounted, the air-
borne particles must not exceed 100 

µ

g/m

3

.

When the repeaters are installed in an environ-

ment that contains small airborne particles, e.g. grain 
dust or salt fog,  the repeater cabinets need to be 
sealed.  A heat exchanger, i.e. air conditioner, is then 
required to cool the cabinets.  The air conditioners 
must be suited for the environment.  Each repeater 
(110W) requires >2400 BTU/hr dissipation to main-
tain exterior cabinet temperature.

The RF modules and the power supply are 

equipped with fans, controlled by thermostats, that 
force air through the equipment for cooling.  The air 
flow is from the front to the back of the equipment.  
This permits the Repeaters to be stacked or rack 
mounted (see Figure 2-4).  There are a few consider-
ations when installing Repeaters to provide adequate 
air circulation.

1. The Repeaters should be mounted with a minimum 

of 6 inches clearance between the front or back of 
the cabinet for air flow.  The power supply requires 
a minimum of 18 inches at the back of the Repeater 
for removal.

2. Cabinet enclosures must provide air vents for ade-

quate air circulation.

3. Temperature and humidity must be considered 

when several Repeaters are installed at a site.  This 
might require air conditioning the site.