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Moonracker YG5-4 transformations

Moonracker YG5-4 transformations. 1/ Original Moonracker YG5-4 2/ YU7EF transformations 3/ SWR meas. Original Moonracker YG5-4. Measures at 70.2 MHz using Mmana simulator. Whole aspect. Dimensions. F/B ratio. SWR. Original Moonracker YG5-4. Original Moonracker design.

griffin-townsend
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Moonracker YG5-4 transformations

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  1. Moonracker YG5-4 transformations 1/ Original Moonracker YG5-4 2/ YU7EF transformations 3/ SWR meas

  2. Original Moonracker YG5-4 Measures at 70.2 MHz using Mmana simulator Whole aspect Dimensions F/B ratio SWR

  3. Original Moonracker YG5-4 Original Moonracker design • Equal spacement between elements • Gamma Mach feed (serious problems with humidity and torque) • F/B ratio not optimised Lboom =2.66m Impossible !!! What’s dBb ?? Gain =7.83 dBd F/B=14 dB

  4. Original Moonracker YG5-4 Gamma mach feeding Gamma capacitor

  5. Original Moonracker YG5-4 Zoom on gamma mach feeding : too much distance !! Difference between diameters 19,85 – 19,07 = 0.78 mm, that’s far too much !!

  6. Original Moonracker YG5-4 Zoom on rear of feeding box Silicon compound Plastic cap

  7. Original Moonracker YG5-4 Zoom on front of the feeding box : All the water can enter here !! Shield contact NOT reliable in the time ! Metal screw WITHOUT dedicated nut part (very ugly) !! Box front (UHF feeding)

  8. Original Moonracker YG5-4 Initial elements fixing on boom and adjusting

  9. Moonracker YG5-4 transforming from YU7EF Measures at 70.2 MHz using Mmana simulator Whole aspect Dimensions F/B ratio SWR

  10. Moonracker YG5-4 transforming from YU7EF Finished antenna • No more equal spacement between elements • Direct 50 Ohm feed

  11. Moonracker YG5-4 transforming from YU7EF Construction of a brand new isolated dipole - Dipole substitution - New elements spacements Gain =7.86 dBd F/B = 18 dB

  12. Moonracker YG5-4 transforming from YU7EF Dipole feeding details Lucoflex plate 300x100 h=4 mm No rain can enter Diam 12/10 mm N connector Plastic box 70x70 h=40 Dipole fixing parts

  13. Moonracker YG5-4 transforming from YU7EF 50 Ohm dipole ends Split on length 30 mm No rain coming from both ends Diam 12 Diam 10

  14. Moonracker YG5-4 : last improvements against rain Aluminium Scotch on all previous holes (here dipole and gamma feeding)

  15. Moonracker YG5-4 measures

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