Thursday, April 15, 2010

UHF Yagi Uda antenna

Addendum, here's the complete antenna (overstatement)...built in 30' with coat hanger wire.
Does it work? Look's so but no QSO so far with Arecibo radio telescope...

Heading to the moon...
Soon as I heard the some crazy guys (KP4AO) are going to frie the moon via EME (http://dxinfo.ea3bhk.com/Special-events/KP4AO-Arecibo-Observatory-Amateur-Radio-Club-on-432-EME.html) I had to do something, at least for some reception.
I like making antennas so here is the oportunity to make one and probably operate something (don't expect that 5w will be enough but since they have big ears we never know) since I never operated SSB on 70cm band... I hope both my capable radios are still working :)

Here's my drawing:


Driver element is feed "live" on the lower side and "ground" on upper side (in the drawing)
and made in #10 copper wire... whatever that means :)... I will get the first wire that look's easy to work and has some style... which is very importan in antenna design

Elements are made of 1/8" diameter which is 0.31cm (3.1mm)

Boom will be made of wooden.

Antenna is made to operate at 432Mhz.... don't try at 20m

Made conversion from "inches" to "cm" based on 2.54cm/Inch, enough accuracy for me.

Original design from here: http://www.wa5vjb.com/yagi-pdf/cheapyagi.pdf

Here's the same design in html format:
http://www.fredspinner.com/W0FMS/CheapYagi/vjbcy.html

Here's another with dimensions rounded from the original article and some construction details: http://personal.inet.fi/koti/olavi.vahamaki/LowCost_432MHz_Yagi.jpg

There's small diferences in sizes... I based my design in original article.

Testing was not done yet...use at your own risk

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