BOOTY 4

[BOOTY MONSTER]

i got a little done on the antenna today and heres a few pics .

heres the bottom bracket . its just 5 inch pieces of 1 inch aluminium angle 1/16 inch thick with a couple of cuts in the sides .

heres one bent more or less into shape .

here they are on the 1 5/8 inch aluminum tube .

i made slits on the end of the 1/2 inch tubing and it slides perfectly over the tab for the bottom of the basket elements . they will be flattened on the end and a 1/4 inch SS bolt , lock washer and nut will fasten them together .

id appreciate some opinions here . i can put the mobile stud (that the bottom of the gamma tube will connect to) right between the tabs , but id like to have it out a lil bit . i just made a mark on a piece of scrap aluminium with a circle where id like to put the stud mount and a line where it will be cut off . should i be ok out a lil or keep it in as close as possible ?

can someone tell me how to make my pics smaller ?
im just using the "img code" from photobucket .

its supposed to be nice here the next few days so hopefully i can get it together over the weekend . more pics will come as i plod along :headbang

 

[pro151]

I think you and HomerBB should add up all of the antennas you have built to see who is the king of home made.

 

[BOOTY MONSTER]

LOL , homer has me beat by a mile !

 

[Marconi]

i got a little done on the antenna today and heres a few pics .

heres the bottom bracket . its just 5 inch pieces of 1 inch aluminium angle 1/16 inch thick with a couple of cuts in the sides .

heres one bent more or less into shape .

here they are on the 1 5/8 inch aluminum tube .

i made slits on the end of the 1/2 inch tubing and it slides perfectly over the tab for the bottom of the basket elements . they will be flattened on the end and a 1/4 inch SS bolt , lock washer and nut will fasten them together .

id appreciate some opinions here . i can put the mobile stud (that the bottom of the gamma tube will connect to) right between the tabs , but id like to have it out a lil bit . i just made a mark on a piece of scrap aluminium with a circle where id like to put the stud mount and a line where it will be cut off . should i be ok out a lil or keep it in as close as possible ?

can someone tell me how to make my pics smaller ?
im just using the "img code" from photobucket .

its supposed to be nice here the next few days so hopefully i can get it together over the weekend . more pics will come as i plod along :headbang

right click on the image in Photobucket and then click on "edit" right below the box with the image, and then follow instructions for resizing tiny, small, medium.

 

[HomerBB]

I may have made more, of which I'm not certain, but Booty seems to work harder at it. I guess I lack a crucial bit of pride.

 

[mackmobile43]

Booty, just open the picture in paint and there you can reduce the size of your pictures before you upload to your host.

 

[BOOTY MONSTER]

thank you to who ever shrunk my pics in the first post
i got a few more pics that i reduced at PB so hopefully it wont be an issue any more .

i got the gamma pretty much done , except for needing another roll of teflon tape to fatten the gamma rod up a lil more , one 260 inch roll wasn't enough . i also need to bend the foot for the bolt to connect to the stud . im gonna fold it under so the bolt/stud is pretty much centered under the middle of the gamma tube . i made sure the bottom of the gamma was neatly rounded and smooth . used a file to get it more or less shaped , stuck the other end in a drill and then sand papered it while spinning .

i also got the 30 inch loop made and drilled for the basket elements . its a single piece of 96 inch by 1 inch aluminum strip 1/8 inch thick . i cut 6 inches off the end of each 6 ft piece of 1/2 inch tubing and made two 1 inch slits on each end one end will be kinda flattened with with the loop sandwiched between the cut end and a 1/4 inch SS nut , bolt and washer securing it . there will also be a slight bend for the angle of the basket radials . the other end simply slides over the 3/8 rod with a hose clamp holding it .

the other 5 1/5 ft sections are slit on both ends to bolt to the bottom bracket and hose clamped at the top to the solid 3/8 rod .

 

[eagle1911]

Looking good! I've got nothing but respect for the DIYers..

 

[HomerBB]

Yep, looking real good, Booty.
Git er dun so ah kin c it. (secret DIYer lingo)

 

[BOOTY MONSTER]

got a lil more done today

heres the tab im wanting to use for the stud . i could put it between the 2 fins , and if it wont tune then ill move it there . but does it look acceptable where it is ?

heres one of the 6 inch pieces of 1/2 inch tube with a one inch slit on each end . i used a 2 1/2ish piece of 1/16 inch 1 inch wide aluminum strip because it looked like the easiest way to make the connection there since it has to have a slight angle . the extra threads on the bolts will be cut off .
all the nuts , bolts and lock washers are 1/4 inch SS.

heres a view from the other side .

heres the loop with the 6 inch pieces on it . its a 96 inch piece of 1/8 thick x 1 inch wide aluminum strip . i made a hole a 1/2 inch from each end for a circumference of 95 inches . divide that by pi and that gives me a 30 1/4 inch diameter .

heres the loop from the other side . not a perfect circle , but hopefully close enough to not cause issues .

and heres one with the 3/8 rod and 1/2 inch tubing showing how the will go together . the 5 1/2 ft pieces of 1/2 inch tubing will connect to the fins on the bottom bracket similar to the tabs on the 6 inch pieces , i may put two nuts and bolts on them ...... ill use 1/2 inch hose clamps for the tube and rod connections .

i think the bottom bracket is fine electrically , but i may re-make it . i think i can make a cleaner looking one .

 

[pro151]

Damn Booty! Going all out this time aren't you. I can't wait to see it assembled and hear your highly unscientific performance results.

Hurry up man, I want to see this one in the air.

 

[BOOTY MONSTER]

well , im hoping this will be the last omni that i need to build . im trying to do as bob85 told me and stay as close to the original designs as possible . it has to be stronger weather wise than those , but i still want it to look pretty good up in the air .

thanks 151

 

[HomerBB]

It's all looking good, Booty. As for how close in the coax connector needs to be to the bottom of the radials I am not sure. At one point when I was fabricating I suspected too much distance from that point might have been causing me problems. I never knew for sure. What I think may be critical is that you keep the Gamma in the circumference of the radials at the point it tops out, that is, that the top of the gamme be the same distance out from the center vertical as the radials are at that point. This may dictate to the distance of the gamma from top to bottom, too. Someone who really knows may have more to say about it.

Anywho, it's lookin' good!

 

[BOOTY MONSTER]

thanks homer
just to clarify ..... the very tip top of the gamma rod ? or the place on the gamma rod where the arm goes back to the center vertical ?

 

[Marconi]

thanks homer
just to clarify ..... the very tip top of the gamma rod ? or the place on the gamma rod where the arm goes back to the center vertical ?

BM, are you looking for the gamma dimensions for the Sigma4 or the Vector? You may have already told us, but which model are you planning to go by for your dimensions?

I think Bob is right. This design may be so complicated as to design vs. response, that every part needs to be carefully measured. It may work otherwise like Homer suggested, mediocre, but based on Bob's experience with his setup and tune and the notable better response he observed at some point...this indicated to me that this antenna probably has to be just right or the best it will do probably won't happen.

My next project here, after I test my Starduster, using a new install setup and making sure everything is tight this time vs. my Gain Master, will be an attempt to try and eek-out some improved performance using the longer radiator idea. I have a 6' foot piece of aluminum now that will go into the top where the original tip is only 4' feet.

I know that Bob used the Vector with 4 radials, and he indicates that the added radial made a noticeable difference. However when I talked to him about my experience using more radials on my Marconi, he was not so sure that I would be able to see a difference just by adding one or two additional radials, so I don't know. Maybe I won't be able to see a notable improvement like he did.

I noticed the nice looking work you did the other day for the bottom hub setup for the radials, and it is hard to tell, but will that set you radials at 90 degrees apart. I think symmetry in this area is critical, because I found my Sigma4 would not tune properly when I inadvertently set my gamma a bit skewed more toward one radial. I also recall Homer having a problem at some point in building one of his models where he changed something in the bottom I think before he got it to tune. That result and the ultimate action taken by Homer escapes me at the moment, maybe he can tell us that experience and how he saw things back then. I think he talked a little about something along these lines in a post or two back, but that too...I'm not too sure.

I commend you guys that build your own stuff, and the success in the project working, but you have to be honest with your self as to how well they work, because I hear guys say, "...just about anything will work" and I have to believe that. I think a big old ground plane with a matching coil might be one thing, but the Sigma4/Vector design might just be another can of worms if it truly is working as a true collinear by design. The 5/8 wave would not be so critical.

Take for example your experience with your 1/4 wave which you were not happy with after building something else. I know a lot of guys will tell you that a 1/4 wave is crap, it is waste of time, a dummy load, and it won't work well...compared to the longer antennas. BUT, that is not what I find, even while every Tom, Dick, and Harry, is telling us there must be something wrong with my location, that I don't see all the remarkable result differences others do. I consider this all a difference of opinion based on personal experiences, but I just don't see the differences everybody else does. Even with the videos, you guys can't or don't believe what you see at my location...even after all these years of my saying virtually the same thing.

I've heard "Wolf Talk" before too, so you know what I think.

I suggest that if you not prepared to test and compare antennas with this new project, then build it just to get it tuned the best you can and don't worry about it working the best it can. Frankly, I don't think you'll be able to tell if it works better or not unless you do some comparisons, because I don't think you've worked much at your new location. I also doubt most of us will ever see, what Bob experienced with his hybrid modified Vector and it looks like it might have been a one time deal maybe. I've see such strange things happen at times while I was watching my antennas respond to different signals, but I consider most of that stuff aberrant and I use greater signal sampling to average such events out of the mix I get and report.

Just making a few comments off the top of my head.

Be sure and let me know if I can help with any dimensions that I might have here.

Good luck, and keep us posted.