Designing Homebrew Yagis is Easy

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@chuckrann6282 6 күн бұрын

Excellent. I built a 4 element quad for 10 meters back in the 80’s on a 16 foot square aluminum boom that rocked. Everyone told me that it was spaced incorrectly, even though I was 20 db over 9. I spaced the 2 directors the driven and the reflector evenly, and did the 5% rule. This was based on a book of quads from Bill Ohr w6 something. So yes the basics you talked about work. Thank you !!!! Now back on the air and working on a 40 m yagi design. Here we go!

@kiweekeith 4 ай бұрын

Thanks So Much for your Wonderful 'Simplistic' Approach .... I 'Sucked Up' Every Word .....Just could not get enough ..... :-) :-) :-) Very Best to You, Yours and All from ChCh, NZ

@bill-2018 Ай бұрын

This does make it easy. You're right, there's all different dimensions of element spacings for Yagi's. Perhaps we should more correctly call them Yagi-Uda beams. I made a note for a five element Yagi for 2m years ago from a design in the ARRL Handbook with element spacings of R to D.E. 16", D.E. to 1st D 12", then two spacings of 20". Three directors reducing by ½" going forwards. It was fed with a coax delta match. It worked okay. I think I'll give this one a go, 5 elements maybe, the hairpin match look easier and the overall design simpler. Thank you. I no longer have the first one or it would have been interesting to compare the two. G4GHB.

@kostyanetrebenko1953 Ай бұрын

Thanks John for this brilliant presentation! Have you tried the rules to design a HF Yagis?

@graphicventures 2 ай бұрын

Thank you so much, cheers from the U.A.E

@hubercats 8 ай бұрын

Excellent presentation! Thanks for sharing your knowledge.

@Joe-ho6fo 19 күн бұрын

Great ideo

@johngraham5521 19 күн бұрын

You state a Gamma Match is hard to adjust. Maybe try this method. Water proof box to hold your air spaced capacitor, Attach rod and adjusting strap. I have a Rig expert AA600, because I have one.no other reason. (working or purchasing a VNA.) I go to all modes and adjust adjusting strap for 50 ohms. Then dip capacitor for close as to 1:1. Then look at dB return loss and see where best spot is. Adjust driven element length accordingly if required. and repeat resistance and capacitance as necessary. . Should put tune spot on quite quickly. Capacitor can be measured and replaced with a fixed capacitor ensuring the correct voltage is used Your thoughts please. John.

@G5MCL 4 ай бұрын

Great video. I love your presentation style. Great Job!!!

@peterfong2241 4 ай бұрын

Well you guys say it's easy, you say it not me, can I have the specification for the 2,3,4,5 element yagi flat side antenna for 11 meter, please an thanks watching from Jamaica west Indies !!.

@W6IWN_Radio 10 ай бұрын

Thanks for the video!

@tomcatmeow69 3 ай бұрын

interesting and useful info. I am surprised with the hairpin system as I thought it would short out the coax and hence transmission signal and blow the transmitter.

@migalito1955 5 ай бұрын

Hmm, I always set my spacing to give a 12.5 ohm impedance where the 12.5 ohms was transformed to 50 ohms by using as the driven element a folded dipole with a wire spacing that multiplied the 12.5 by 4. This turned out to be common speaker wire. As far as being flimsy wire, it was taped to dowels similar to the fiberglass rods. Any method you know that works is good enough and I do like the simplicity of the method shown here.

@dylanschulz2404 3 ай бұрын

By fiddling around with some modeling software, it brought me to the 12.5 ohm impedance for an optimum gain and FB ration 3 element. Using the simple 2 rule tactic made my 20 meter project over 24' long for a 3 element beam! haha Modeled out pretty good but I was able to get the FB ration better by moving the driven closer to the reflector. The .2 WL on the director does work out pretty close to maximum gain though.

@NVRMTmotion 3 ай бұрын

Love this approach! What impact does the different diameters most store-bought yagis use for reflector, radiator, and the parasitics?

@magnusterminus4728 7 ай бұрын

Thank you 😃👍

@kylemauseth7579 9 ай бұрын

Thanks for sharing!

@davidnewman7490 10 ай бұрын

Super video, thanks for posting.

@LCSRacing 9 ай бұрын

Thank you, do you need to consider the width of beam when deciding on the element lengths? I.e.. is it simply the amount exposed or includes material passing thru the beam?

@tomstrum6259 9 ай бұрын

I still Don't completely Understand exactly How the 3 Element yagi works....Would a 3 Element Optical Equivalent using a Mirror reflector, 360° light bulb Source & Convex Lens produce an Easier to understand & Improve 3 Element yagi antenna ??

@Gabaab 4 ай бұрын

antennas work on radio frequency, not light. optics and mirrors. have nothing to do with this.

@JDBolt1958 2 ай бұрын

@@Gabaab The question is indeed a good one. Radio waves and light waves share the property of traveling at the speed of light. Light and radio waves being part of the electromagnetic spectrum exhibit constructive and destructive interference. This property of constructive and destructive interference is the behavior which the Yagi takes advantage of to focus a radio wave in the forward direction. The frequency of the light from a filament light bulb has an exceptionally low frequency as the typically supplied AC household current oscillates at 60Hz, not 3500 (80 meter band) or 144,000 (2 Meter Band) thousand. In fact, turning a light switch on can produce a radio wave due to the spark which is created within the switch when contact is broken. So light and the principles of optics are indeed closely related to radio waves and can be helpful in illustrating how a Yagi works.

@tomstrum6259 9 ай бұрын

My accurately Calculated & precision Built/Cut & feed Match 10 element Vhf & Uhf yagi antennas Based on your Recommended model Performs only 75--85% as good as Commercially available 10 Element yagis.....What's wrong & how can I Recover the Lost 15--25% Gain potential ??.....Thx for all your Helpful info....