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.
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
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.
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.
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.
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 !!.
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?
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....
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 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.
Thanks John for this brilliant presentation! Have you tried the rules to design a HF Yagis?
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.
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
Excellent presentation! Thanks for sharing your knowledge.
Great video. I love your presentation style. Great Job!!!
Love this approach!
What impact does the different diameters most store-bought yagis use for reflector, radiator, and the parasitics?
Thank you so much, cheers from the U.A.E
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.
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.
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.
Thanks for the video!
Super video, thanks for posting.
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 !!.
Thanks for sharing!
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?
Thank you 😃👍
Many thank's for this video John ! How calculate the gain of the antenna ? Thank you for your response,
best 73 !
F5JXS Louis
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....
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 ??
antennas work on radio frequency, not light. optics and mirrors. have nothing to do with this.
@@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.
It's just as easy to drill PVC pipe as wood.
It is harder to keep the elements centered in plane