5/8 wave @ 37'

[Needle Bender]

Thank you guys for taking my questions.

NB here are some of the V58 dimensions I see in the manual, Rev 2/10, or else I just took a guess. I don't own a V58.

The hoop radius on the V58 is determined by bracket part P08P and is 5.5" x 0.50" x 0.125" inches. This part is made up of the bracket, SO239, and the wire.

The other bracket part R02P is 7.75"........ inches and it slants up to connect to the base assembly part of the radiator at the top of BA1P.

I don't know how long the base assembly BA1P is...as it comes in the kit, but I've guessed it to be approximately 57" inches overall and maybe a bit more.

I think BA1P is preassembled and is not adjustable as to the overall length. If one needs to adjust the radiator length then the element T43P above BA1P will need to be adjusted up or down. T43P is noted to be 48" inches long and is set 6" inches inside BA1P to allow for adjustments.

The manual says to adjust the radiator length at the point of the element in the top of part BA1P as noted in my comments above.

There is a big bold note for this adjustment point on page 5, where the whole antenna is imaged and the parts are referenced by number.

There are more dimensions I have questions on, but right now my model with the manuals dimensions is showing the radiator to be very short and needing more inductive reactance...no matter where I put the tap point on the 35" inch long tuning coil.

Does anyone know the overall length of BA1P and the location of the spider hub RO3P?

Homer is your radiator glued into the pvc in the base of your antenna?

Ed, I'm not sure what BA1P is, and perhaps the antenna I bought used was not a true Maco but one of the several copies marketed under the Tram, Workman or other names, but this one had 5 pieces of radiator tubing, 4 x 48" (1", .875", .75" & .625") & 1 x 72" x .5" (top).
Your estimate of the ring-match tubing length is close @ 35" but might be a little short, 5.5" plus 1/2 of the 1" diameter radiator base tube x 2 = 12" minus a slight lip of maybe 1/4" outside of the outer edge of where the 3/8" diameter ring-match tubing hole was drilled for a bolt, to where the hole was drilled at the outer end of P08P, leaving about 11.5" - 11.75" outside diameter of the ring match, x 3.1416 = 36.125" - 36.9" plus the 270° more I added = ~64" total length of the matching ring tubing to the top ring arm which I refashioned to match the lower P08P, so basically two P08Ps, the 2nd at the top of the new longer ring match.
Ring match tubing is now ~64" + radiator length of 273.5" (electrical length) for 1.05:1 swr @ 27.185MHz, X = ~2 & 51Ω is what I read on my handy-dandy MFJ "world's best" antenna analyzer.

 

[Marconi]

NB, I was not planning on getting back to modeling my V58, but I did go to check the size of the coil.

I checked in my file for my V58 model and I found the info I was asking about back in 2013 from Camaro1 on this forum. He answered this question for another member named Jok.

new Sirio Tornado review / update

Camaro and this other member saw the issues in their real world antennas that I did in my model. Where is the bottom of the V58 antenna that Maco uses to determine the overall length values they give us in the manual?

With that said however, the information above does not solve my problem with my model...it still shows a boat load of capacitance and the inductive coil specs noted in the manual are not good enough to help eliminate the problem. I'm not saying my model works and the antenna doesn't. I am obviously missing something in my model that produces the necessary inductance with the smaller coils we have discussed here.

To get my to work with the matcher added, I have to make the antenna closer to the true 5/8 wavelength and I get a perfect match with the coil size I made and the radiator length set at 267.29"L x 0.80"D inches and radials at 104"L x 0.55"D inches.

Thanks for the help.

 

[Needle Bender]

NB, I was not planning on getting back to modeling my V58, but I did go to check the size of the coil.

I checked in my file for my V58 model and I found the info I was asking about back in 2013 from Camaro1 on this forum. He answered this question for another member named Jok.

new Sirio Tornado review / update

Camaro and this other member saw the issues in their real world antennas that I did in my model. Where is the bottom of the V58 antenna that Maco uses to determine the overall length values they give us in the manual?

With that said however, the information above does not solve my problem with my model...it still shows a boat load of capacitance and the inductive coil specs noted in the manual are not good enough to help eliminate the problem. I'm not saying my model works and the antenna doesn't. I am obviously missing something in my model that produces the necessary inductance with the smaller coils we have discussed here.

To get my to work with the matcher added, I have to make the antenna closer to the true 5/8 wavelength and I get a perfect match with the coil size I made and the radiator length set at 267.29"L x 0.80"D inches and radials at 104"L x 0.55"D inches.

Thanks for the help.

Well, that really doesn't address the gist of my last post about my .64 only loosely based on a Maco, nor is it a 5/8.
I just imagined you'd possibly want to try modeling a slightly different, longer take on the perennial 5/8.
And I did specify that none of the radiator on my .64 slides down inside the base causing additional capacitance.

 

[Marconi]

I didn't mean to ignore your comments, I was feeling bad today and I was struggling to even pay attention. I have fluid in my lungs and I go to the Dr. in the morning. It may just be the weather, pollution, and pollen that has me messed up.

Yesterday I had this V58 model on my mind and I'm puzzled with what I'm missing in that construction. Today I wanted to try and fix it...but I was in a fog of and on all day.

Maybe tomorrow.

 

[Needle Bender]

I didn't mean to ignore your comments, I was feeling bad today and I was struggling to even pay attention. I have fluid in my lungs and I go to the Dr. in the morning. It may just be the weather, pollution, and pollen that has me messed up.

Yesterday I had this V58 model on my mind and I'm puzzled with what I'm missing in that construction. Today I wanted to try and fix it...but I was in a fog of and on all day.

Maybe tomorrow.

Roger, feel better, ok?!!

 

[Needle Bender]

Here in my sometimes Scotch & Cigar-stained fingers I'm holding an OEM 1975 Hy-gain "Super Penetrator 500" matching network, taking measurements to post for Marconi.
I can't get my pics to upload for some reason so I did me best w/o.

The overall total length is 16.5"

The top U-turn is 3"

The two sides are 1" apart

The length across the half-loops is 3.5"
The length of the half-loops if straightened out is 6.5"

The length of the longer left-side lower section is 9"
The length of the shorter right-side lower section is 7 3/8"

At the bottom of the 9" lower-leg section is a 45° bend in toward the radiator & bolt, 3/4" long
- plus another 1/2" added from the end of the 3/4" 45° to the bolt hole center, bent 45° to flatten back out & parallel the upper section.

At the bottom of the 7 3/8" shorter lower-leg section is another 45° bend in toward the radiator 1.5" long plus an additional 3/8" section bent back to parallel with the radiator - to the center of the bolt hole.

-------------------

The ground shunt is 10 3/4" tall, the bottom horizontal section which connects to the RF-Hot bottom insulator bolt is 2 3/4" long to the center of the bolt hole, the upper horizontal section which bolts to the adjacent radial bolt is 1 3/8" to center of bolt hole.

Here's a good pic of the ground shunt from Jim Dent's site, main match looks a bit different, perhaps he custom made it without the 45° ends.

 

[Marconi]

Well, that really doesn't address the gist of my last post about my .64 only loosely based on a Maco, nor is it a 5/8.
I just imagined you'd possibly want to try modeling a slightly different, longer take on the perennial 5/8.
And I did specify that none of the radiator on my .64 slides down inside the base causing additional capacitance.

NB, I looked over your post #46 of several days ago and what you describe as your .64 is basically what I did with my original model in this thread. Excepting for a few differences noted in the following link of this thread that I posted earlier my model and your antenna are very similar.

Click on the link below and then open the attached PDF file.

5/8 wave @ 37'

The only exceptions are my model "Homer's .625w x 9'R wC 36' a" is a bit longer at 267.7" inches, and I made the coil longer by making the diameter 16" inches that produced a total wire length near 66" inches which is close to your overall coil length of <>64" inches. My model also does not have the radiator down inside of the base mount assembly like the Maco and Homer's antenna does. My model also has horizontal legs 1" apart for the coil like you suggest. My model also uses 108" radials. I can't do tapper using Eznec and generate any kink of accuracy, so I average the element lengths for the radiator at 0.875" inches and .0.60" inches for the radials. This too will likely cause some difference.

That said however, my model also shows a nearly perfect match at 27.205 where I modeled the resonance, so we are close and you won't get any argument from me on this count. My model is pretty close to what your MFJ shows for the match and I can make it even better by moving the tap point one more segment. How do you like that sports-fans?

NB'r does this give you a bit more confidence in the results an Eznec model can demonstrate?

However, the point is my model and your antenna are not set to the specs for the Maco nor Homer's antenna...if I understand his dimensions as posted. This is why I am curious as to how to model the V58 correctly.

 

[JAF0]

If I'm not in trouble for bringing up this several month old posting I'll add mine by stating I made a 5/8 a few years ago with a 49.25" long full-circle match not including the arms to hold it in place and which measured about 15.625" in diameter. I made my radiator tube 268" but there was about 3/4" inch below the point where the arm connects the ring to the radiator, so it's more like 267 1/4" with 1.25" tubing at the bottom tapering down to 3/8" tubing at the top.
I connected a capacitor from the bottom ring arm bolt where the coax feeds it, to the radials hub but I don't recall the value of the capacitor and the 4 radials were 3/4" dia down to 5/8" down to 1/2" dia and are 8' 9" long, plus an inch or two of the radial hub bracket.
It performs quite well at about 42' above the backyard lawn and seems to out talk and out receive a maco v58 my neighbor has up about 45' above his roof.
We both have Yeasu ft757gx2s, I bought his backup rig. My 5/8 performs so well he wants me to help him modify his maco to be just like mine but I just haven't had the time yet.
We both do a local net on 10m where his maco is tuned but I use an LDG auto-tuner since my 5/8 is tuned flat swrs down at 27.205.
my .02c