Difference between 2-element Yagi vs. Dipole
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- Опубликовано: 9 фев 2025
- Difference between a homebrew 15m 2-element Yagi and a homebrew rotatable Dipole on my roof in Seoul, Korea. The Yagi was actually a bit quieter than this yesterday, but I've been playing with the length of the elements, and the coil, to make for stronger transmit. This boom is only 1.5m long. I would like to extend it to 2.3m long, so I can make it about 50 ohms with no coil inductor. The elements are fiberglass fishing poles, and 16 gauge solid house wire. When cutting house wiring such as this, which as a plastic coating, you need to reduce the element sizes by 3% from normal calculations. The plastic coating makes the elements electrically longer than bare wire. This change is due to "velocity" of the wire. I use an app called, "Antenna Tool" from the Google App store.
Nice video. Thanks for posting. Until two days ago I ran a homebrew rotatable dipole on 20M and had great results with it. It was up on the tower about 3 years. I fed it with exactly 3 wavelengths of LMR400 and a dual core balun mounted right at the dipole.
Tuesday afternoon (going on three days ago) I finished putting up a 20M mono band hexbeam, taking the dipole down, as I wanted my hexbeam mounted on top of my small tower, right at 35 feet where the dipole was. Interesting also is before I moved into the house I am in now, I ran a homebrew 2 element yagi - a driven element and a director on this same tower at 35 feet. I fed the two element yagi with a gamma match. Seemed to work very well but for some reason I got to tinkering with it and ended up taking it down some years ago.
I have noticed a real difference in performance in the hexbeam over my dipole and have asked several times in QSO if others have noticed a marked up-tick in 20M activity and no one has made any comment that they think the band is better recently than it has been for some time - and with sun spots at a low, 20M has not been too active for quite some time. Well, I am here to tell every one, 20M is sure a lot more alive at my QTH than I have seen it in any recent memory. I am truly surprised and pleased with the performance of the hexbeam. I run a homebrew amp using a 4CX1000A and about 1200 watts PEP to the antenna and get fabulous reports. Actually, I got great reports with the dipole too.
Just thought I would throw my 2 cents in about the hexbeam and compliment you on your homebrew antennas - especially building a yagi - nice job. 73 WA4QGA El Paso, TX
Great video. The reduction in noise is a huge benefit that operators don't mention. If you can boost your RX by 2 s points and drop the noise by 2 s points then that's effectively a 4 s point improvement!
I remember going from a dipole to homebrew 3 el. Yagi for 15 m. in 1967. My rcvr had no S meter, but the difference in performance was huge. My 1st QSO was with Japan, my first outside NA! 73 K5RX
Not surprised the Yagi has noticeable gain over the dipole but a bit surprised at the noise on the dipole. I wonder how the noise varied as you rotated the dipole and Yagi? The dipole would pick up signals and noise off both sides while the Yagi does not. I suspect there is one direction where the noise would be worse on the Yagi ( due to its gain.) However it could be the location of the dipole (nearer to a noise source) or the feedline routing. The dipole should have nulls off the ends whereas the Yagi has both front to back and usually nulls off the back quarters or the sides, depending on exact design.
Merci très intéressant ce comparatif
73's to France
I'm impressed with the dipole :)
Dipole does pretty good.
I have since taken this yagi down, built another, and taken that down... both worked well. The reason for removing them was because I left on a long vacation before storm season, and wanted to take my antennas down. I haven't bothered to put a 15m beam back up. I have since built a 20m Moxon antenna, and it works great. Even though it's a 20m monobander, I can tune it and use it on 15m and 17m. I would rather have dedicated 2-el antennas for those bands, but as much as I use those bands in this sun cycle, I get along fine with tuning the 20m moxon down to them. I was able to make 4 longpath contacts on 17m today, using the 20m moxon (although I know receive isn't as keen as an actual dedicated 2-el). I highly recommend hams try building a 2-el yagi antenna. They are pretty simple. I will be adding some plans for wire yagis on my blog: TheStingyHam
Great video 73 Tony Ridlen KC9QVE Marion,Indiana
Hi Derek, I just reduced my antenna mast height 2 weeks ago, fear of extreme weather condition nowadays. SO while it is summer I had the chance to bring some pipes down. It is just around 30ft now. Maybe I can start that homebrewed HF antenna that you shared with me not so long ago hihihi...Many thanks 73 and MABUHAY !!!
I use fandipoles for 160 thru 6 meters
Good demo
Hello, good job 👏 would you please write down the yagi 2 elementals dimensions, i will try to make one ...73
My 3 elemrnt yagi is sometimes noisier than my vertical. As far as recieve and transmit it depends on propagation. I flip back and forth to determine which is right for the contact.
Would help to see S meter difference if you use Slow AGC for SSB. Also change the filter BW to 3kHz. Enjoyed the video K9RJ
Could you please draw a plan for your 2 element yagi cheers Garry
I am on vacation overseas for a few weeks. I'll look for it when I return. Sorry!
That would be fantastic God Bless and besafe
Hi Derek. Nice comparison, tnx for video. But i have to say, that on 15M band you should set RX on p.amp1. Because of accurate S value, due to manufacturer instructions. With IPO-ON is your background noise level very small and not accurate :)
Derek i very hope to will speak with you sometime on the band. I never had QSO with HS. 73, good luck and happy new year!
OMOET It is difficult to quantify S-meter improvements between radios, I am learning
Is that a full-size yagi? if it is can you provide me the measurement please,i will like to build a copy of that antenna...73 k3ibm
Same op under another account, here. I don’t have the original plans for that, but what I did was took the 20 m Yagi template from Managal software and modified it to the 15 m band. Yes it is a full size Yagi on 15. After playing around with different antennas my suggestion would be to build a 15 m Moxon Yagi instead, and just follow the Moxon design software which is free on the Internet. I made another video about Moxons under this channel.
On your YAGI, have you chosen a reflector or a director
Honestly cannot remember which. I have tried both.
вполне предсказуемый результат.
Spider quad. Light. Cheap. Gain and super quiet.
2 S Points ? 12db..hmm must be like a 4 element quad then hey :)
Better you try make this comparasion in weak signals.
The guy was over 5,200 miles away, and the only other choice was EU over the pole (which was not coming in that day). We work with what we have available.
@@thestingyham1188 i know. But with sinal s3 for example try compare it its better
These ant ennas r to close together r affecting each other to b accurate
The greater the number of parasitic elements you have, the greater the rejection you will achieve.
your "H" call sign must be a vanity, am I correct?, couldn't locate it through data base. Just curious.
Thanks for sharing!
Kind regards, Eric Dee.
I am on qrz.com as HL1ZIX. I am living and working in South Korea. The call is issued here in Korea. As for your comment about parasitic elements and rejection, you are correct, but for a moment, I thought you were commenting on my dating life before marriage. :)
73 de 14PAT83
Just turn up the power going out will pick up the 2 s units
Doesn't help me on Rx, to raise power. I have made more efficient yagis than this, now that I have more experience. I am amazed at how I can hear DX signals and just QSO with them, while hearing nothing with the dipole. This can mean a day of making 15 contacts from Korea to Europe, vs maybe 3 or 4 contacts to the same area on the dipole.
Great video! de W2CSI