11 meter dipole problems

[Robb]

Sounds like you are on the right track. I agree with Doc too.

Don't give up now; you are closing in on it. Shorten it by 1 inch on both sides - change it equally. Don't cut anything; just re-fold it on the ends - that way you can change it back a little if you have to. Re-calibrate. Re-test. Repeat. You're almost there!!!!!!

 

[arkie guide]

If it is still 9' long on each side it is too long, too.

I agree that the dipole needs to be tighter, flattened out horizontally, or the middle higher than the ends.

Sir, is 16' +_ are 8' per side, the right length? 108"is 9' are 1/4 wave. what is the problem with the 108? Thank you.

 

[arkie guide]

Not to steal the thread. I have A DIY, 3 element 11-meter antenna. DR is 16' +- is that wrong? Also is 18' a good height with 18' of co-ax? to check the antenna out.
Thank you sir.

 

[Crawdad]

Not to steal the thread. I have A DIY, 3 element 11-meter antenna. DR is 16' +- is that wrong? Also is 18' a good height with 18' of co-ax? to check the antenna out.
Thank you sir.

Sir, is 16' +_ are 8' per side, the right length? 108"is 9' are 1/4 wave. what is the problem with the 108? Thank you.

Coax length is not important in this case. Don't fall for the old CB myth that your coax needs to be some certain length.

468/Freq in MHz= half-wavelength dipole

234/Freq in MHz= one half or "pole" of half-wavelength dipole

Those formulas will always leave your wire longer than necessary to allow trimming for tuning to resonance or low VSWR, whichever blows your skirt up.

 

[BJ radionut]

 

[Crawdad]

View attachment 64680

Gary, do you have a link to that Yagi calculator?

7 3

 

[BJ radionut]

https://www.wa2ooo.com/yagicalculator.html

4 Element Yagi Building - IW5EDI Simone - Ham-Radio

4 Element Yagi Building This article contains discussion of all the different antenna principles previously described elsewhere on this website. A thorough reading and understanding of the other sections are necessary to comprehend all the terms used on this page. It is not necessary to...

www.iw5edi.com

 

[BJ radionut]

Yagi calculator

Maple Leaf Communications - Antenna Calculator - 3-Element Yagi

Use our simple calculator to determine approximate dimensions of materials needed to build a 3-element Yagi/Uda antenna, and then shop for your needs on our other pages and select from our inventory of aluminum, fiberglass, coax, connectors, and other parts and accessories for amateur radio and...

www.mapleleafcom.com

 

[arkie guide]

I averaged 8 different measurements for a 27 mhz. 3 element beam, results.
R=18.15' //// DE=17.19'////D=16.19' - I used the above chart ad using 27.5 mhz. came out with these R=18.22'////DE=17.2'////D=16.18'. This chart comes out to close to the averages I figured. I may change mine to - R=18.20 ///DE=17.2
D=16.2 --- I have been out for many years just trying to catch back up. Thanks.

 

[Ranch55]

8.5' long for each wire, put up in an inverted "V" formation with a minimum 90* included angle at the coax connector.......

 

[jtrouter]

Sir, is 16' +_ are 8' per side, the right length? 108"is 9' are 1/4 wave. what is the problem with the 108? Thank you.

Just A FYI the thread is 12 years old. Just so you know the dates are on the threads.

 

[HomerBB]

Sir, is 16' +_ are 8' per side, the right length? 108"is 9' are 1/4 wave. what is the problem with the 108? Thank you.

The problem with the 108" is it's too long.
Also, if it is a yagi you're building the driven element length is affected by the parasitic elements on the boom with it, their diameters, the spacing between, and proximity to the earth, and other influential structures nearby.
Some of these same things can affect a simple dipole, too. As for 9' being a 1/4ʎ, it is if your center frequency is around 26mhz.

 

[Ranch55]

468/27.205 = 17.2027 ft. /2 = 8.601 ft per leg .......

468 divided by frequency = total dipole length
total dipole length divided by 2 = length per leg