Building a HEAVY DUTY 28 MHz Dipole Antenna

[@HamRadioDX]

EASY to Build 10M Vertical from Coax 👉 kzbin.info/www/bejne/eGLOXqyYh7N1f6csi=VVOPVmnH3gOznAZd 6m Moxon Antenna 👉 kzbin.info/www/bejne/qmewhoabfpZ-nposi=fgXIhUOFEyEw8Cl1 Build a Common Mode Choke 👉 kzbin.info/www/bejne/qGPHloWrhL19nKssi=0SOoe6d-zLG4JiZA Note - a more approximate value for calculating the leg of each dipole is: 142/frequency. This takes into consideration velocity factors and real-world factors that might slightly alter these lengths based on the environment, conductive properties of materials, and other considerations in antenna design. Either way, making your dipole slightly longer and then trimming it to tune is the way to go.

[@RingwayManchester]

Nice one Hayden!

[@HamRadioDX]

Thanks Lewis

[@LifeAtTerminalVelocity]

That looks like it is going to be a Skookum Choocher.

[@1shARyn3]

No red button to press. It's now a black bell

[@spaceflight1019]

Very interesting propagation today. On 28.515, at 18:20Z, I copied a South African station in QSO with a station near Wellington, NZ. Time in SA was 20:20; time in NZ was 07:20. The SA station has his beam pointed to North America. Even though I live near Pittsburgh, and could copy both stations easily, I couldn't reach either of them with the 1011 and Penetrator. About an hour later, the California Highway Patrol started coming through on my scanner. I think that I'll set up my computer for FT8 on 50.313 and see what I get.

[@user-regenRX]

Wondering about affects of square tubing being so close to both elements.

[@HamRadioDX]

I modelled it in MMANA and there are next to no affects apart from a few ohms of reactance that you can tune out.

[@garryhammond3117]

@@HamRadioDX - Strange. How/why is that? - Is it because the square tubing is relatively short in relation to the full length of the elements?

[@mikeZL3XD7029]

@@garryhammond3117 That shouldn't make a lot of difference, in the grand scheme of things, I would have expected there would be some sort of a capacitive component in there, but as Hayden mentioned, this can be tuned out, if necessary.

[@temporarilyoffline]

Nice Stuff Mate

[@HamRadioDX]

Thanks 👍

[@W4TRI_Ronny]

Might want to poke a pinhole in the bottom cap to drain out any moisture. Nice build!

[@HamRadioDX]

Yes! For sure!

[@TRIPPLEJAY00]

Awesome bro, looks great. The buzz you get must be high.

[@ktanner11]

I used a piece of aluminum channel and couple pieces of aluminum angle and 2 102" whips. Been up like 8 years works great

[@dan_in_sd]

Nice build. Very neat and tidy. 😃

[@HamRadioDX]

Thanks! 👍

[@DellFargus]

I did a similar 10m dipole when I first got licensed, but I used copper pipe. It didn't work, couldn't tune it below 3:1. It also looked hideous, and my wife made me take it down. I wish you more luck than I had. Maybe I'll see in your videos where I went wrong! Rubber caps on the antenna will bigly move the resonance. For example, on a firestick (27MHz CB antenna), taking the cap off will raise the resonance up into 28 MHz. There's a chart on their website showing cap on vs. cap off vs with stinger in vs. stinger out. Although that may be comparing apples to oranges (whip vs. dipole). My point is test it before you climb the tower, so you only have to climb once.

[@ehayes5217]

Boy, that IS a heavy-duty one!👍 de WA4ELW in TN 🇺🇸 dit dit 😃

[@alanthomas8817]

you beauty 😂 been searching for those type of clamps for my spiderbeam pole with no sucess... until NOW Thanks

[@HamRadioDX]

Cool!

[@AdamCasner]

Following this one closely. Would love to get something like this up on the house. So far i have only made the cheaper 10m with speaker wire.. But i need something more permenant. Have a good one!

[@rodkessell2248]

Stauff clamps 12.7mm = 1/2" not 1" Another great vid and very well thought out Hayden.. 👍

[@mikeZL3XD7029]

@rodkessel2248, A lot of us down this way don't have to deal with imperial sizes. But yeah..

[@DXCommanderHQ]

Top Banana Mate!

[@HamRadioDX]

Thanks Cal!

[@James_Bowie]

Your formula omitted velocity factor, which in this case will be factored into the tuning optimization process. 12.7 mm is 0.5 inch.

[@HamRadioDX]

Yes that's correct.

[@michaelross-aj6fgvk3rz]

Left out length/diameter ratio compensation also.

[@HamRadioDX]

@@michaelross-aj6fgvk3rz Will get you in the ballpark

[@peterpauldonoghue7024]

12.7mm is half inch

[@HamRadioDX]

Metric to Imperial is not my bread and butter 😆

[@meggalavk3ktt]

it looks like you have been in my shed looking forward to hitting your repeater. great idea the the glads for the feed point . Why a dipole and not just a vertical like a half wave?

[@HamRadioDX]

Side mounting a vertical is a little more difficult, plus an end fed antenna (such as a Statiomaster) needs a counterpoise too. They tend to whip around in the wind and would get caught in the tower.

[@DonzLockz]

I like your well explained projects Hayden. I'm just curious about all the non aluminium metal if its galvanised or stainless, being close to the freezing ocean down there. :)

[@HamRadioDX]

Most of the time it's galvanised. Otherwise rust and dissimilar metals becomes a problem

[@mikeZL3XD7029]

Hi Hayden, This looks like a really good design. However, the screw mountings for the enclosure that go into the square boom, were these "Tek-screws" (as in self drilling screws)? Only reason I ask this is that aluminium is shocking as taking an actual thread and over time, they will round out (making the thread give up between the parent metal and the screw threads), causing the holes to slop out and come loose, especially with wind causing the elements to vibrate the whole enclosure, etc. Personally, I would bolt them through the boom to the other side, believe me, this will save you grief later on.

[@HamRadioDX]

Hi Mike, I ended up going with another antenna for the repeater, but it is downstairs... I tapped holes and put Bolts into the aluminum. You're right, Tek screws would come loose over time.

[@mikeZL3XD7029]

@@HamRadioDX Nah, good as gold Hayden, it's just that I come from one of the windiest parts of New Zealand, everything will eventually get shaken to bits over here, if it's not a big Nor'wester, it's a massive Southerly!

[@michaelross-aj6fgvk3rz]

300/f x 0.5 is free space length. That ignores VF of the aluminium tubing and the length/diameter ratio.

[@daviddavidson1372]

if you build this for receive only do you still need the choke?? And yeah was looking for those clamps. thank's for letting the cat out of the bag.....

[@HamRadioDX]

You could build it without the choke. A choke might be recommended near the end of the feedline (where it enters the shack) to reduce noise pickup on the cable.

[@daviddavidson1372]

@@HamRadioDX ok great. 10m fm was wide open for about an hour today into north Carolina... great videos...Thanks

[@HowToHam_Tom]

If you don’t patent that and market it I will! That is HamFabulous

[@HamRadioDX]

Very large to ship!

[@gregf9160]

Basically, those tips might act as a "capacity hat" (thus, affect the _electrical_ length of the dipole) but not much, I imagine 🤗😀

[@HamRadioDX]

Yeah I think the effects are much higher at say VHF or UHF

[@robmyers985]

Not Pustek clamps, they are Stauff clamps, pronounced storf.

[@ErikS101]

Why do Scottish and Australians pronounce their T’s like CH? Tubing is chubing?

[@HamRadioDX]

Because if we all spoke the same that would be boring wouldn’t it…

[@DonzLockz]

Choobing. Lol

[@CoveiraoPS3]

You have a tower to deploy the antenna on, you know how to build a moxon and yagi. Why would you waste resources on a dipole? It feels like you’re allergic to DX

[@HamRadioDX]

Suggest you rewatch the video.. maybe at half speed.

[@butchdingle1000]

Why oh why would you waste your time... Just build a heavy duty vertical 🙂

[@HamRadioDX]

Side mounting a heavy duty vertical that is 5 metres long, and making sure it doesn't whip into the tower in high winds is a bit harder than a simple dipole.

[@HowToHam_Tom]

This kinda IS since it’s minted vertically isn’t it? What is the efficiency loss between the 2 in reality? I like this plan.

[@HamRadioDX]

It is mounted vertically (as per the thumbnail photo). Just easier for the particular application and tower it is to be mounted on. I have two other verticals (one an end fed, that needs a counterpoise) and a 5/8 (that has radials too large).