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Monday, July 26, 2010

Easy Eggbeater Antenna
For Amateur Radio to work with Satellite
Requirements :-
1) Copper or Aluminum Tube or solid Rod (4 to 5mm)
2) Cable RG 58 ( 50 OHMS)
3) Mast PVC
4) PVC Base
5) Nut, bolt etc.
          Eggbeater Antenna consist of two Loops , Both the loops are connected to each other with RG 58,(50 ohms) it should be quarter wave length , Solder outer shield at both the end and the center conductor connects to the loops as shown in the Fig.1 . The impedance of the phasing line is 100 ohms. So point 1, 2 and point 3, 4 is 50 ohms

Circumference for Each Loop Should be 215.28 CM For VHF
Phasing Line should be 34.15 CM For VHF

Circumference for Each Loop should be 75.90 CM For UHF
Phasing Line should be 11.38 CM For UHF

          For better understanding The above Fig.1 show the loops are separated , Both the loops are full wave mounted at right angle to each other and coupled together and one inside another, Fig 4 shows about mounting these loops This antenna is omni directional circularly polarized.,( FIG 2) this design is good for Low Earth orbiting Satellites also by adding the reflectors “GAIN” can be improved , At point “X” a nylon washer or any isolator is to be use, Both the loops should not be touching each other

           To match the unbalanced source(RG 58) to a balance load (antenna )We will use BALUN that will be 4:1, This BALUN will give an impedance step up ratio of 4:1 as the impedance of the feeder is 50 ohms it will provide a match for 200 ohms terminating impedance, also to convert the high output Impedance of the BALUN(200 ohms) to 50 ohms impedance of the antenna balanced line that is QSECTION must be added to it Refer to FIG 3
Length of the Q section should be 34.15 CM for VHF
Length of the BALUN 4:1 should be 68.20 CM for VHF

Length of the Q section should be 11.38 CM for UHF
Length of the BALUN 4:1 should be 22.76 CM for UHF
Eggbeater Antenna View From Top

Have try to simplified the idea OF 0n6wg/f5vif (thanks for everything ) for better understanding ,
DE JAYESH (…- ..- ..--- .. …- …-)