Thinking about making my first experimental Di-Pole for my garage. ( Got Questions )

[Alabama Buckeye]

Plenty of Romex wire on hand - Antenna wire (check)
2X 44"L 12-14AWG stranded wire on hand - Balun wire (check)
4" PVC pipe and end caps - Balun encasement and SO238 mount (check)
FT240-43 Toroid on hand - Balun foundation
2X SO239 ( ??? )
ABS plastic sheeting 1/16-1/8" - Insulators
2X #8 1" nuts and screws -
eye bolt

Sounds to be your dipole is ready
Agreed with Crawdad, in my experience it'll be closer to 8' than 8.6' (8' 7.2")
Winding the FT240 toroid with 12-14AWG solid copper wire is a difficult process. Use the stranded wire, either will handle plenty of watts.

 

[Crawdad]

Winding the FT240 toroid with 12-14AWG solid copper wire is a difficult process. Use the stranded wire, either will handle plenty of watts.

I couldn't disagree more. Winding mine with the solid copper was not difficult at all and the wire forms to the toroid and the pairs stayed together much better than stranded does. Will be doing another one soon for an antenna I'm building and I plan on doing the same thing.

A good read on chokes and baluns:
http://k9yc.com/2018Cookbook.pdf

 

[whiteastro]

234/Frequency in MHz=length of one "pole" in feet.
468/Frequency in MHz= overall length of "dipole"

234/27.185= 8.608 ft. = 8'-1/4"
My experience is that I've always had to trim wire off to tune to my desired frequency using this equation.
But like Riverman said it never hurts to cut long to give yourself enough rope to secure the ends.

Thanks for the input, is that considered a 1/4 wave? Is there a advantage to doing a 1/2 wave or more. My garage is 40' long and I'd hang it along side the garage in a inverted V pattern to start with. ( Which faces South West ) Where I would get most of the signal from anyway.

 

[Crawdad]

That formula is for a Half wavelength. Quarter wavelength dipoles dont work very well.

 

[whiteastro]

That formula is for a Half wavelength. Quarter wavelength dipoles dont work very well.

Thanks

 

[Shadetree Mechanic]

No need to cut the ends to tune, just fold the ends over.

 

[whiteastro]

No need to cut the ends to tune, just fold the ends over.

Thanks that is what I figured. I'll study my eBay ready made Di-pole in the attic first. It's called R&D ( Research & Duplicate ) LOL !

 

[Alabama Buckeye]

I couldn't disagree more. Winding mine with the solid copper was not difficult at all and the wire forms to the toroid and the pairs stayed together much better than stranded does. Will be doing another one soon for an antenna I'm building and I plan on doing the same thing.

A good read on chokes and baluns:
http://k9yc.com/2018Cookbook.pdf

Perhaps the 12AWG "magnet" wire is hardr-bendum copper, same with 14AWG mag. wire. Fingers hurt trying to bend it. 16AWG Remington magnet wire was bendable. With the right tools, instead of fingers, Romex 12AWG is bendable to properly wind a Toroid? Lacquer coating shield on magnet wire is susceptible to damage from tools. I should have specified.

 

[Alabama Buckeye]

Whiteastro, I'd like to chime with the succinct answer. It's magic!

A 18' MOL radiating element, a monopole, is a 1/2λ antenna; but, a 9' radiating element on a dipole is also a 1/2λ antenna. The monopole is half an antenna but the dipole is a whole antenna. I'm telling ya, it's magic Seems to me a dipole is a 1/4λ whole antenna. Refer back to succinct answer.

 

[whiteastro]

I couldn't disagree more. Winding mine with the solid copper was not difficult at all and the wire forms to the toroid and the pairs stayed together much better than stranded does. Will be doing another one soon for an antenna I'm building and I plan on doing the same thing.

A good read on chokes and baluns:
http://k9yc.com/2018Cookbook.pdf

Looks like good info but is over my head with no electronic training and no friends to explain it. I think I'll use the KISS Theory. LOL

 

[Alabama Buckeye]

Your basic bug-out pocket dipole. These 4 windings, pictured, wud not be my choice. Can't find the table demonstrating frequency, windings and SWR. Best I recall, for 10/11M, 10 resulted in a reading of 1.2:1 and 14 windings resulted in better than 1:1; don't know how that works, maybe something like that wattage generating coax. If that were so I'd make it 21 windings of LMR100 (if available). Therefore I strive for 12 windings on a FT240 toroid. Aside from the protection from weather corrosion and absence antenna elements it's all here. Again best I recall, 12 tightly wound RG58 on FT240-43, with no wriggle room was less than 38".

There's bound to be argument on the extent of "tightly" wound toroid can cause migration of center conductor towards the shielding, over time. Coax is precisely engineered to retain that conductor centered. The spendy higher Velocity Factor LMR flavored coax with "foam" conductor insulation (FE) may migrate off-center when the bend is too sharp and under stress. I've not the hand strength to cause that much stress, under normal conditions, on the radius bending for PE insulated coax. It is the inside diameter closeness/tightness that is of importance to accommodate 12 windings. You can't get 12 windings of RG-8X on a FT240-43. BTW, the 43 is the cake mix used to make the FT.

 

[Alabama Buckeye]

Whiteastro
That scooter in your avatar picture looks like a Yamaha 1100 Virago I once rode? I rode it to Datona Bike Week a couple decades ago.
Was enjoying a couple frosty ones in an local country pub when a group of Hardly-Ableson riders came in. A few minutes later one of the group asked loudly to the patrons, "who owns that Yamaha outside". I acknowledged ownership, and he said alarmingly, "it's leaking all over the place". I briskly jumped up and exited to my bike. Upon arrival I found a mound of rice on the ground under it.
I turned around, I'm sure I had a smile on my face, to the roaring laughter of the crowd; I was happy to join in.

Tesla Model X 670HP 1020 #ft Torque 0-60 2.5 seconds. I know what 0-60 in 3.5 seconds feels like. My Triumph Rocket III, 2300CC 145HP 158 #Ft melted the tread off a fatty car tire in 8 months. Top shelf cycle tires didn't last 6 months.

 

[whiteastro]

Whiteastro
That scooter in your avatar picture looks like a Yamaha 1100 Virago I once rode? I rode it to Datona Bike Week a couple decades ago.
Was enjoying a couple frosty ones in an local country pub when a group of Hardly-Ableson riders came in. A few minutes later one of the group asked loudly to the patrons, "who owns that Yamaha outside". I acknowledged ownership, and he said alarmingly, "it's leaking all over the place". I briskly jumped up and exited to my bike. Upon arrival I found a mound of rice on the ground under it.
I turned around, I'm sure I had a smile on my face, to the roaring laughter of the crowd; I was happy to join in.

Tesla Model X 670HP 1020 #ft Torque 0-60 2.5 seconds. I know what 0-60 in 3.5 seconds feels like. My Triumph Rocket III, 2300CC 145HP 158 #Ft melted the tread off a fatty car tire in 8 months.

Glad to see you enjoy riding your scooter also and you are partially correct because it is a Yamaha Virago. But the Nature and reason of our riding is different. Mine is for the many short local hauls and fuel economy on these hilly, windy, pot hole ridden roads of N/E PA. My bike is only a 250 cc and reaps me about 75-80 MPG which I love in these times of high gas prices. I once was going to buy a Yamaha 535 Virago to get the shaft drive instead of chain drive but checked and the MPG would drop to around 50 MPG which would defeat my purpose of riding. Yes there is a lot of jokes about the Rice Burners but there also is the one about ( I'd Rather ride my Honda than Push my Harley ) That bike always starts and doesn't drip oil and I laugh when I go by the pumps and see the down trodden people filling up their SUVs & Ford F 150, 250, & 350s and all their hauling is their Butts. For the long hauls I use my little Chevy Cobalt and when the Work has to be done I drag out the WhiteAstro Van. LOL

 

[Beetle]

"Dipole!" That's what Vladimir yelled when he stabbed Stanislavski.

...or so I thought when I first heard that story.

 

[Alabama Buckeye]

OK Beetle, I got it. Stay on topic.
No exchanging recipes nor mentioning your fly is open.
And I won't be mentioning Iron Horse Saloon, Ormond Beach, is a carnival of fun.
and miles of 4-wheeler parking