Ham Radio Antenna: Simple 3 Band No Radials Vertical for 20, 15 & 10 Metres

Рет қаралды 3,351

Күн бұрын

I have been looking forward to building and testing this antenna out for a while!
It tunes well and spoiler alert.. It radiates well too (that video will be out soon!).
Connect with my channel by subscribing & commenting. Also, if you have an antenna question, email me: TimG5TM@icloud.com
73
Tim

Пікірлер: 43

@badlychosenwebname 15 күн бұрын

Worked fine with minor adjustments. Mine was too. sharp on 20 metres. I will have another go when time permits, as it is a great solution at one of my sites. :-)

@alzeNL 2 ай бұрын

I'll be quite honest, antenna building is my least favourtie part of the hobby, but i always enjoy your videos and explanations, feel like I've learned something and look forward to the practical demo. Thanks all your hard work on the amateur radio front, its great how you do nice antenna theory and live broadcasts... dont know how you find the time :D 73 2E0FWE

@timg5tm941 2 ай бұрын

You are very kind Al! It’s a very enjoyable hobby!! 73 mate

@chrisjones8741 2 ай бұрын

Ooooh, I like this idea, thanks for sharing! I don’t have an HF antenna yet at all and this looks simple enough and like it might be a good fit for my very small yard.

@timg5tm941 2 ай бұрын

Glad it was helpful!

@TheSmokinApe 2 ай бұрын

Awesome job Tim 👍

@timg5tm941 2 ай бұрын

Thanks Ape!

@MikeN2MAK 2 ай бұрын

Looking forward to seeing it in action!

@timg5tm941 2 ай бұрын

Video is out!

@M7BCN 2 ай бұрын

Very promising figures Tim. I already have some spare 10 and 15m Cushcraft traps and a 7m fibreglass pole. Might give this a go. Looking forward to the next one buddy.

@timg5tm941 2 ай бұрын

Thanks mate!

@WECB640 2 ай бұрын

Tim, this looks great! At 4:53 you had me perplexed because the antenna is elevated 1m above ground. I just modeled it and while the SWR is different if you mount at the ground level vs. 1m above gnd, the pattern and the gain remains basically the same. This is because it is 1/2 lambda in length. Looking forward to the follow-up video where this build is placed on the air. KEEP BUILDING! 73 OM

@timg5tm941 2 ай бұрын

Thank you sir!

@HAMRADIOBRASIL 2 ай бұрын

Very interessant 👏🏻👏🏻👏🏻

@timg5tm941 2 ай бұрын

Glad you think so!

@om0wt 2 ай бұрын

Hi Tim. What are the traps details? How many windings, wire diameter, pipe diameter? Thanks. Pavol

@richarddavison9137 2 ай бұрын

wow I love it can you tell me about the traps please former size and turns would have been helpfull , I like building antennas and seeing what i can do with regards to vswr , is there a plan for it ? cheers VK5OVT , 73

@timg5tm941 2 ай бұрын

Hi Richard - I can look into a video on trap designs. I might pop a link to more info on my community tab on youtube too.

@IrishHamRadio 2 ай бұрын

Hi Tim, Once I saw the title on this I was really keen to watch so saved it for my porridge and toast this morning 😊… Great video and I think this is actually my next project! To be honest all my builds have been resonant antennas and for some reason I just can’t get my head around making traps, specifically how to calculate the turns/former, how to actually measure they are correct for the band and finally where to put them…. 😅 Maybe you have this back in your content somewhere, but I have yet to find a really good explanation on traps and how to make them from the beginning to the end, including how to test them for a specific band… Would you be able to point me to this if you’ve already published it, or maybe even consider doing such a video?…. As you would be the best man to describe it! For me for example, this would be a portable antenna to carry up a SOTA summit, so my traps would need to be very light coax or some other trap option lighter than rg58 . I would likely also use it with the tuner then for 40m to give you UK folk some chaser points too! 😊

@timg5tm941 2 ай бұрын

Hi Dave - I can point people to how to make the traps - I also have a n idea for a 20/40m dual bander which does need radials but no tuner if that would help?

@IrishHamRadio 2 ай бұрын

@@timg5tm941 yep, the 40/20 would be perfect for sota/wwff in my case... expecially if i can get it up with the 7m sotabeams pole. On the traps, yes id love to see the process of making a trap from start to finish, through an example antenna build... Im also interested in loading coils too, particularly to load a shorter wire for 40m portable.

@timg5tm941 2 ай бұрын

@@IrishHamRadio right that’s on the list 👍

@M0JSX 2 ай бұрын

Excellent idea Tim. Could a third trap be added to get 17m? Or substitute the 15m trap for a 17m?

@timg5tm941 2 ай бұрын

Yes you could substitute it. Perhaps 17 could be added? Might be worth a look!

@M0JSX 2 ай бұрын

@@timg5tm941 I need to learn how to model that!

@timg5tm941 2 ай бұрын

@@M0JSX happy to help mate

@paulsengupta971 2 ай бұрын

We could have an antenna which is 50% traps...I wonder how having traps for all the bands would affect 20m?

@aeron-mw7ofs 2 ай бұрын

👍👍

@timg5tm941 2 ай бұрын

Ta!

@brianfields4479 2 ай бұрын

Another very interesting ant tim, do you think ,there is any advantages adding a heap of radials on this type of ant. 73

@badlychosenwebname 2 ай бұрын

It doesn't need it with the Unun at 49, or 64 to 1, but there is no reason not to try it just for fun. Experimentation should be encouraged. 🙂

@timg5tm941 2 ай бұрын

Nothing compared with adding radials to a quarter wave. I’m doing a video on that one soon

@justmejonboy 2 ай бұрын

What LC values did you add yo MMANA for the traps, I’ve worked them out but they don’t seem to work the lengths in the design. 28.5 1.5uH 20pF 21.2 2uH 27pf

@pulponair 2 ай бұрын

I was wondering: Isn't the 10m Trap drastically lowering the 20m efficency because it is placed close to the 20m current maximum and thereby working against a relative low impedance from the 20m point of view? Even a high Q trap for e.g. 28mhz still has arround 7db attenuation againts 50ohm. Is that something to concern or have i made a mind mistake?

@timg5tm941 2 ай бұрын

I used to think this, but Cebik produced a paper which outlined that placing coils at the current maximum on a dipole (near centre) only had a fractional reduction in efficiency compared with midway down each leg. This contrasts with a ground vertical where the interaction with the ground itself is what makes a coil near the current maximum the big issue compared with loading the antenna away from the current maximum. The same applies here as the efhw current maximum is well above ground Level so it behaves more like a dipole than a 1/4 wave ground fed.

@pulponair 2 ай бұрын

@@timg5tm941 I need to check out this paper. I am not 100% sure if one can simply apply the findings for a coil to a trap. Even though those coax traps look like a coil they are in fact a well defined parallel LC circuit having a super high impedance at resonance. Intuitively i would place them as far away as possible from the current maximum of any band i want to use the antenna on. But as mentioned i might be totally thinking in the wrong direction :). Need to do more research on this topic. Thanks for sending me down this rabbit hole ;)