Khuyến Nghị Sử Dụng Máy Đo Antenna Feeder – Viavi JD745B

Testing devices are mainly used for the following testing requests: 

 

 

  • Distance to Fault (DTF):

This is an important testing way for the process of installation, operation and Broadcast station maintainance. The purpose of this testing article is to determine abnormal positions on the feeder antenna system. For example: cables bent, cables twisted, connector defected, antenna defected…

 

 

The values of Voltage Standing Wave Ratio (VSWR) or Return Loss values are often measured and displayed.

Normally VSWR is accepted with Feeder 1.05 and antenna is 1.3.

  • Always use calibration kit along with the machine in order to calibrate before testing. Only use testing cables along with the machine.
  • Cable loss

Determine loss value of the cables with different frequencies. The goal is to ensure the loss which is caused by feeder is within the acceptable limit.

  • Power measurement

 

 

Determine in two directions: direction = transmitter power of the broadcast stations; Direction: power obtained from the antenna.

  • Mount the load to the OUT head of the power meter first
  • Connect the IN port of the power meter to the transmitter station or RRH

 

 

 

  • Channel scanner

Measuring and determining power level of chanels with different frequencies and different mobile technologies.

 

 

Notice:

  • Signal input power > +25 dBm / 50V DC (RF In / Cable and Antenna Analyzer);
    > +40 dBm / 50V DC (RF In / Spectrum Analyzer port); > +37 dBm / 50V DC (Reflection / RF Out / Cable and Antenna Analyzer) can damage the meter
  • Continuous usage time: about 3 hours
  • Store the equipment in a temperature range of 0-40 degrees.

 

 

Connecting computers:

Can connect with computers through JDViewer dedicated software with USB cables or LAN cables in order to:

- Control, configure, measuring from a far distance.

- Take the saved results in the meter.

- Make reports

- Analyze measuring results.



Tin khác