Antenna construction cross Yagi, VHF band, 6 elements, 2 meters long, circular polarization, 9dB gain

Useful links:
Notes on 6-Element Wide-Band 2-Meter Yagis
http://on5au.be/content/a10/vhf/32m.html
Antenna Circular Polarization
https://www.qsl.net/sv1bsx/antenna-pol/polarization.html
Yagi Uda Antenna Calculator
https://www.changpuak.ch/electronics/yagi_uda_antenna_DL6WU.php
Coaxial Power Split Calculator
https://www.changpuak.ch/electronics/coaxial_power_split.php
Calculate the extra length of coax feeding the other dipole for circular polarisation
http://dg7ybn.de/Building/xpol.htm

Drawings…
VHF antenna design, 6 elements, 2 meters long, 9dB gain


UHF antenna design, 2 meters long, 12 elements, 12dB gain

Be aware of the cable loss!!!
I used this Antenna (Vector-Network) Analyser to measure the cable loss…

Here you see the loss of a 15m long, RG58 (50Ω, Ø4mm, ordinary) cable.
The loss is considerable in VHF – 5dB, and enormous in UHF – more than 9dB.
-9dB means that only 10% of your power is passing thru.
Almost the entire antenna gain is lost over the cable.
So a high quality, thick, expensive cable is mandatory, especially in UHF. RG58 is to be used for short connections, of less than 3 meters.

2 comments

  1. Hi,

    Thanks for very useful information.

    Is it possible to sell a pair of VHF & UHF satellite antenna qty 01 each ?
    Please let me know the delivery period and cost ?

  2. Hello Kumar,
    Sorry, I can’t do that.
    The materials are very cheap, but the manufacture is entirely done by hand, no automation at all, and this will be very expensive. Plus the shipment is very complicated, because of the big size.
    I hope you can find someone near you, who can do it for a more convenient deal.
    Sincerely,
    Racov

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