Home-Brew Sigma 4

[BOOTY MONSTER]

tried my hand at making a sigma v . sirio currently makes their vector 4000 which is their version of that type of antenna , but i continuously read comments on forums about the 4000 not be durable in bad weather areas . we dont get nor'easters or more than a foot or so of snow in my area , but we do get hurricanes and pretty high winds at times . so i decided to roll the dice and make one that i think will be sturdy enough . my initial ideas for construction didn't work as well as i though they would so i had to re think and buy new material to make into the parts i wanted . it took a while , but i got it done . here's a link to the entire thread for anyone that may be interested in seeing how it progressed for me as well as my mistakes i made along the way .

http://www.worldwidedx.com/home-brew-mo ... y-4-a.html

im just gonna post pics here of what i ended up with . im starting with a 29 ft vertical length , 108 inch basket element length and a 30 inch loop . the gamma is 3/8 solid aluminum rod and 1/2 inch inside diameter aluminum tubing . i used a simple mobile stud for the coax/gamma connection .

here's the bottom bracket .....




here's the loop with tabs for the basket elements and the basket elements .




putting basket elements on the bottom bracket .



my gamma strap .



a pic of the basket .





and the finished (for now) antenna .





not me in the pic , just one of my buds .

put my astatic 700 meter on it real quick and got a quick and dirty 1.6 or 35 and did a quick check with 2 locals . just sitting literally on the ground it made a good contact with a guy in the city that my other 5/8's just barely made through the static . even though its much taller , its a whole heck of a lot lighter than my 5/8s with the big plate and mounting boards

[pioneer]

very tidy job there.

Mark

[bigpimp347]

this one looks like it will last in a tornado..!!

excellent construction, why couldn't sirio copy yours..!!!

[MrWeetabix]

Good man! Great work, let us know when production is in full swing and we'll get you some sales

[BOOTY MONSTER]

thanks guys

LOL , no production planned
i just wanted one much stronger physically and weather wise compared to what sirio is currently selling . but hopefully my adventure/mistakes may help someone else wanting to make one them self . if someone sees part of it worthy of copying for their use i'd of course be flattered .

i do have a few refinements to do to it .... maybe next month .
i'll post pics if/when i do them

thanks again for the kind words .

[HomerBB]

Booty, you got it going on. Real nice job.

[northern35s]

That's pretty damned fine and dandy, good effort booty

[crusty]

Well engineered, great project, congratulations.

[simon26OD004]

Booty, I've been watching both yours and Homers projects since you both started the V4K homebrews, and I have to say I'm very very impressed. I don't have anywhere to put something that big, but if I did I think I'd be copying yours for sure. I now fully expect you to tune that thing for absolute maximum gain on the horizon just like Bob has done with his modified stock vector, and wait to hear the results

Got to ask though, what was the total cost in parts? It certainly looks a lot better and stronger mechanically than a stock vector does.

[BOOTY MONSTER]

thanks again for the kind words .

simon , if the tubing was got all at one time from DXengineering it cost $86.04 delivered .
the 3/8 rod from a local supplier was about $27 plus gas and time for the 50-60 mile round trip to get it .
the plate came of a piece that cost me about $15 i think .
the flat strip material cost about $35ish from lowes .
stainless steel nuts , bolts and washers from homepot about $20 - $25 .
hose clamps from lowes $6 . DX's hose clamps stripped easily ... dont get them .
$3 bucks worth of teflon tape and electrical tape for the gamma insulator .
the coax stud came off a 6 or 7 buck mirror mount .
$4 for a black fiber metal cutting blade . highly recomended !

lots of time thinking , designing and redesigning and making parts and sliting tubing and installing and drilling parts to keep them straight .

so its about the same cost as a vector delivered ..... not including gas/time to get parts locally and a lot of effort ... IMO .
but it's much stronger physically and i have home-brew bragging rights .
using the black metal cutting blade for the circle saw does kinda melt some aluminum on the cut , BUT , the side of the blade is extremely handy for rough cleaning and rounding corners on parts cut with it . using a fine or medium hand file with a flat and rounded side finishes up things nicely . when re-doing a few things the SS hardware seized and snapped on a few bolts when taking them off . i'll be using #8 hardened and plated fasteners on antennas from now on .

im gonna get more tubing to double wall the two bottom sections and make a few other changes . i'll update the thread as i do those .

so , if you have a drill and some bits , a few wrenches/sockets , a skil saw and some vice-grips (aluminum gets very hot when cutting it) along with the time and confidence to make it ..... money wise it's very similar .

but the feeling when getting compliments on a antenna you made yourself is ...... PRICELESS !

[wa10]

im loving it booty , after all that messing with 5/8wave groundplanes you finally made the right choice,
j-pole jay wanted $400 + shipping to build one so you are well ahead ,

when you get the bottom double skinned you will have a booty4 as strong or stronger than the i10k with better performance for less money plus the feeling of "i built that myself"

[HomerBB]

Even with my hardware store Plumbers Delight version it has proven to me to be more rugged than what the original has a reputation for. On two recent occasions with winds reaching at least 90 MPH (the 65 MPH plus I reported was measured at 90) the antenna proved its mettle. My failure was the fiberglass insulator below the antenna which is no longer used.

Booty's clean sharp model looks as if it will do the job, too.

I did not double the the lower section for strength, but rely instead on the fluted harder drawn aluminum of the game retrieval pole that makes up the lower 12' of my model. So far it has worked, but should indications suggest I follow Booty's example I will.

I am encouraged by his willingness to take on this project to continue playing with the antennas. I hope others will do the same.

I understand this antenna is long/tall (mine is currently 31.5'). As for having room, what should be noted is that this antenna uses more vertical space where the sky is the limit, but horizontally it requires only the width/diameter of the ring - 30" or so. I've seen some bemoan their inability to mount an antenna very high due to guying limitations for longer masts. This antenna has shown me the ability to work as low as 10' - 20' off the ground. It hears excellently, talks superbly, and works DX like a dancer on a stainless steel pole even at those low heights. On a 10' pole this thing tops out at 37' to 41' based on whether you use the 3/4ƛ or the 7/8ƛ lengths. That's getting it higher than most antennas without guying it off. A mere 18' pole could put you 45' t0 49' at the tip. and even a 20' pole would require the most modestly spread guys and get this thing up there. Attaching a mast to the side of a home would eliminate guys and open up options. If you can set up an A99 you can set this small footprint antenna up, too.

Booty, you do all' us homebrewers proud with this beauty.

[BOOTY MONSTER]

awwww ..... you guys are gonna make my head swell up
but homer , i don't think i would have had the confidence to try this without seeing your success with your home-brew of it . i don't recall anyone home-brewing one except for homer and i immensely respect him for fearlessly home-brewing where no one had gone before ! i figured if a cajun can do it a ol' fat fart might be able to get 'er dun to .. . the thing that intimidated me the most about it was the gamma match . trying to understand how going open circuit on the hot side of the coax just 10 inches from the feed-point could possibly power the rest of the antenna . i still don't understand it , but i don't need to understand how it works as long as i can copy it close enough physically to make it work electrically . i also didn't understand how short circuiting coax would damage the transmitter ...... but tapping a coil or ring to tune a 5/8 wouldn't . not that i understand all that now .....

several things that made me want to have one is the lower TOA , the claim that it isn't as effected by nearby objects as much as other antennas , its horizontal width of only 30 inches total , and its reported performance at lower/moderate feed-point levels . im sure for the $400 price tag jay wanted to build one that it would be a whole lot cleaner looking , but by the time i double wall the bottom sections ill have about half that much money invested in mine . if we take the time to build , see mistakes , take apart , re-plan re-build and learning as i go along , the extra $200 for jays may start to look like more of a deal . but there is value in lessons learned from trial and error ....

having your vector (or any home-brew antenna ) survive 90 mph winds is a real achievement homer !! you can go on most any forum and find threads about most any retail omni cb antenna failing in similar or less wind . more bragging rights for you

I understand this antenna is long/tall (mine is currently 31.5'). As for having room, what should be noted is that this antenna uses more vertical space where the sky is the limit, but horizontally it requires only the width/diameter of the ring - 30" or so. I've seen some bemoan their inability to mount an antenna very high due to guying limitations for longer masts. This antenna has shown me the ability to work as low as 10' - 20' off the ground. It hears excellently, talks superbly, and works DX like a dancer on a stainless steel pole even at those low heights. On a 10' pole this thing tops out at 37' to 41' based on whether you use the 3/4ƛ or the 7/8ƛ lengths. That's getting it higher than most antennas without guying it off. A mere 18' pole could put you 45' t0 49' at the tip. and even a 20' pole would require the most modestly spread guys and get this thing up there. Attaching a mast to the side of a home would eliminate guys and open up options. If you can set up an A99 you can set this small footprint antenna up, too.

some of the reasons i tried this

[NITRO]

Looks like a good job very well done mr booty Looks to b e very well made and sturdy too..let us know how you get on with it mate ...brilliant job and looks the bizz

[CobraSFX]

A great read and adventure m8, nice work and good of you to share your knowledge