TX antenna - 2EL antenna array 4 direction

This revision is from 2018/05/16 22:27. You can Restore it.

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This is TX-RX antenna mainly for lower bands. It is based on classic 4SQ with 90deg phase hybrid.

Quick Start Guide

  • ⚠ NOTE: Input SWR of the hybrid is not SWR of the antenna!!!

Connector description

  • There is standart RJ45 (ETHERNET) connector with shielding

  • There is standart D-SUB 15 female connector with shielding

  • Table

There is a few ways how to do the right antenna elements tunning.

  • With SWR LED bar indication
    • Do *SWR LED bar settings at first
    • TX with your TRX on RTTY (FSK) and tune TRX over the band
    • You can see, where is the minimum power in dummy load = best SWR
    • You can increase PWR (use PA) and find the minimum
    • So if you set full scale of LED bar graf to 200W, and you TX with 2 KW into the antenna, you can see SWR 2:1 range
  • With 2-port VNA or Spectrum Analyser with TG
    • Very nice way how to SEE antenna parameters is with VNA or SA
    • Connect TX and RX port with short cable and do calibration
    • Than connect TX port of VNA (TG on SA) to the IN port of hybrid
    • RX port of VNA (IN of SA) connect to Dummy LOAD port on hybrid
    • Connect all antenna elements
    • Connect controller
    • Now you cas see S21 parameters of antenna
    • This will change with direction switching
    • You can see the minimum of S21 what is the best SWR of antenna
    • Frequency where there is that minimum, there is best SWR of antenna
    • For example S21 = -20dB means 1/100 of Input power to dummy load
    • On right tunned elements you can have more than -30dB ! what is 1W from 1kW !!!

- Return loss (RL) in dB to SWR:

ONLINE calculator RL to SWR

ToDo

  • Cable wiring circuits