Quarter wavelength wire vertical needs no trimming
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- เผยแพร่เมื่อ 11 ธ.ค. 2024
- You don't always need to precisely cut your antenna if you have a part of it coiled up and switched. Here I take 4.6m of thin insulated wire and connected it to five shorter pieces (about 10cm long) wired across a rotary switch. This allows its length to be varied. The advantage of this is that you can cover about a 10% frequency range rather than the 3% that a fixed length antenna covers. This experiment was with a 1/4 wavelength vertical on 14 MHz but if you want to do it for 28 MHz I would suggest using about 2.3m for the vertical element and pieces of 5cm long across the contacts of the rotary switch.
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Nice! Thankyou. What you don't see in most TH-cam videos, are the results from minor adjustments made. It makes a huge difference to see these things, which is what your videos often offer. Thanks again from the UK.
This is a great idea for a temporary antenna and the wee tuning coil on the rotary is also useful for the a bit of adjustment, I was really surprised by exactly how much difference the ground reflection was a factor thanks for demonstrating this and its its usefulness as a portable and or temporary solution for an antenna, cheers Peter.
MM7BXH
That’s pretty slick Peter. I always love seeing what you come up with.
It must be nippy down there Peter, not barefoot and in shorts today! Love your videos....
Just have to wait ten minutes in Melbourne and the shorts can go back on and the shoes off!!
Spain was one of my first DX contacts after getting my novice in 1980. I was using a converted Thorn CB in the car plugged in to a one element 10m quad about 1.5m above the ground. I wish I still had the bits for that Quad, it was a great antenna during the highs of the sunspot cycle.
Yet another great idea from VK3YE thanks Peter 73
This is slick! I approve
Great stuff Peter. This gives me ideas. Thank you very much.
What a neat idea. Thanks for sharing!
I have added different wire lengths to the feed of the antenna without the switch. And found that it will select the lowest resonance on its own. path of least resistance according to the tuned freq in the radio. Makes an antenna that will give a broad band width across the entire band.
Another excellent video and another thing for me to try. Thanks.
Excellent idea
So simple but effective, FT8 & SSB👍🏻
This is an EXCELLENT idea! Great work.
I'm sure this can be adapted. A inverted L on top band at 1.975 covering 1.950 -2.000. Might be 36.5 metre ? Adding a metre might put me on 1.900 mhz ? Adding 2.2 metre might put me on 1.84 mhz ? I would avoid the switch and just add the extra wire with strong conection ?
Also a 40 metre vert GP at 10 metre also works on 15 metre as 3/4 . Adding a1.8 metre would make it a 3/4 on 17 metre ?
Or a 3/4 on 10 metre is 7.5 metre adding 2.5 metre will give you 40 and 15 metre bands ?
Your experiment has given me a few ideas . Great video film .
Nice vid, Sting!
Regards the non resonant antenna comments at the start, I found some amateurs are not consistent. They will reject the idea of an extended double zepp (5/8 either side of the feed point) because it is not a resonate antenna but will embrace a 5/8 vertical even though it is not resonant.
You could also put a bullet connector at the top of the wire and add a bit of wire making a wire pre cut for 10m longer for 15m and another to make it 20m suitable and so on. Still has your clever switch idea, but becomes multiple antenna's in one. Finding a rotary switch that would handle 100+w would be the hardest part I guess. But as a multi band antenna idea for portable one person operation, it's a winner in my book. Now the idea is out in the ether, it will be available from China on ebay in a matter of days......
Great idea, and kudos to you for building your own stuff. I'm sure this is confusing to new hams, when there are videos like this and operators who go out of their way to make a resonant antenna/system, while others buy a wideband "do everything" antenna for >$500usd which requires an antenna tuner and is not resonant on anything. Guess which system works better? Lol 73
Great idea. Thnx.
Great stuff 👍👍
Maybe a 1:64 balun at the feed point and it would be a 10m end fed dipole and the switch could still be used to adjust resonance? I don't know if the resonance purists would accept end feds with their matching units though? 🤔
Could you place about 8 radials of .125 wavelength or 2.5meter radials and left those to get the same results. Having a less foot print on the ground.
☀☀☀☀☀ FOO WAS HERE
Add a relay-motor to it to adjust it from inside the house
That's what I was thinking. Even a few relays might be an alternative where you could switch in or short out the additional little loops to adjust the length.
Fascinating video, yet again. Have you considered putting some sort of makeshift "dead-cat" on your mic to cut the wind noise? Video quality is almost meaningless when you're telling a good story or sharing useful information. On the other hand, painful audio noise can destroy even the best story.
What antenna analyzer are you demo-ing? That looks nice a simple not how some jam pack the display like medical equipment.
Antuino from HF Sigs. Did a video review of it a while back.
What is the SWR meter you were using? Is that the Antuino?
Yes.
@@vk3ye Could you share the SWR meter's documentation, link or maybe do a video (or if you have a video)?
Thanks for making this one--do enjoy your insights and exploits!
@@SpinStar1956 Yes, there's a review video. Link from the review section of my website vk3ye.com
@@vk3ye Thanks Peter for the quick reply. I did look at your video and gave it a 👍
ohh great.
Brush your hair brother . Lol
Our lad’s too busy doing science! 😃
Would you tell Einstein to brush his hair?🤪