Beams

This chapter is called beams because it will handle all antennas wich are capable of producing a beam with the radiation pattern. Just think of a beam as a flashlight where you point the flashlight. There is light. With a beam antenna it is almost the same.

The patterns are for receiving aswell as transmitting....again...in the antenna pattern there is no difference betweeen those looked at gain or F/B.

 Looking at Front to back (especially with the high numebers) for any figure above 30 dB you can not forget that this is at its highest point 100khz besides the design frequencie the FB maybe dropped 10 dB. If you want to know more about a design let me know through email .
With this diagram you can see what your antenna system is producing when looked at the gain.

THE BELOW DESIGNS ARE DESIGNED WITH THE COMPUTER PROGRAM EZNEC,
5 different designs are tested. I could not find any proof that figures were not real and the antennas were running as expected....GREAT!
For the future I hope to test all models, but as always time is limited. Please read the other chapters to understand more about beamwith, gain, front to back etc.

2 elements yagi                        5 elements Yagi                 6 elements Yagi
3 elements Yagi                        4 elements Yagi                 7 elements yagi

2 elements Quad                     4 elements Quad              6 elements Quad
3 elements Quad
                          5 elements Quad              7 elements Quad
 
Yagi         Yagi versus Quad


expected gain

This diagram is what you could expect from your antenna, not what the manufacturer is telling you!
When compared the below diagram to the diagram in chapter manufactureres please NOTICE that the last mentioned is in dBI in stead of the below dBD (so +2,14dB).

The above diagram (gain versus boomlenght) you will find  figures based on real life measurements and computer simulation.
Figures in real live could difference with what this diagram is telling, but the bounderies are within a single dB!

Remember it is NOT the number of elements on a Boom that makes the gain.
For its biggest part gain comes from BoomLENGHT!                                                                                                                 

BACK