thinking of making a 102" into a base antenna

[522]

im on the fence with this one.

im thinking of moving my dipole from my fence in the back yard (7 feet) to the top of my roof. ( 20 ish feet) probably will keep the dipole horizontal for concealment reasons, and also for DX reasons.

BUT, im also thinking that maybe it would be just as easy to take the spare 102" whip i already have, and put some radials on it, and put that guy on the roof.

i can easily make a small tripod mount to attach the whip to.

my concern is, do the ground radials need to be at roughly 45 degrees ? and also, i just factored snow into the equation. i was worried about snow covering up my horizontal dipole on the flat roof i have here. will snow covering up the ground radials affect anything worth worrying about ?

 

[mackmobile43]

90 to 45 degrees is good.

 

[BOOTY MONSTER]

a easy way to make ground elements for that will be using four 9 ft pieces of wire going from the feedpoint down to a x . the x can be made of pvc or anything else you want to use that is strong enough , light enough and non-conductive . i used 1 inch pvc from lowes . two things i would change on it if i did it now would be to use metal for the mast and make the x smaller . one 10 ft piece of 1 inch pvc cut into four 30 inch pieces with a 1 inch pvc 4-way makes a nice stand off . use your whip on the top . a mobile mirror mount make a easy way to attach the coax , hold the antenna to the mast and attach the ground elements to .

Tips and tricks on how to build your own CB Antennas.

 

[Mudfoot]

a easy way to make ground elements for that will be using four 9 ft pieces of wire going from the feedpoint down to a x . the x can be made of pvc or anything else you want to use that is strong enough , light enough and non-conductive . i used 1 inch pvc from lowes . two things i would change on it if i did it now would be to use metal for the mast and make the x smaller . one 10 ft piece of 1 inch pvc cut into four 3 inch pieces with a 1 inch pvc 4-way makes a nice stand off . use your whip on the top . a mobile mirror mount make a easy way to attach the coax , hold the antenna to the mast and attach the ground elements to .

Tips and tricks on how to build your own CB Antennas.

Several locals have these.

They call them Carousel antennas. Old dude down street has had his up since early 70's. One guy still makes them for those that are interested.

 

[522]

Im almost certain I will go with the 102" or even a piece of emt conduit as the antenna.

i am going to home brew a tripod that the 102" whip or the conduit will sit on. im thinking of making the feed point about 3 feet above the roof line.

the next step was the radials. is there a gauge of wire that is suggested ? i was thinking of some 14 or 16 gauge speaker wire.

i also saw that home depot has 1/2" X 10' emt conduit for $2.05 !

i was thinking that this would be as cheap if not cheaper than the 14 or 16 gauge speaker wire idea i had planned for the radials.

would the conduit work better ?

also, what would be better; 3 or 4 radials ??

Thanks !!

 

[Robb]

Im almost certain I will go with the 102" or even a piece of emt conduit as the antenna.

i am going to home brew a tripod that the 102" whip or the conduit will sit on. im thinking of making the feed point about 3 feet above the roof line.

the next step was the radials. is there a gauge of wire that is suggested ? i was thinking of some 14 or 16 gauge speaker wire.

i also saw that home depot has 1/2" X 10' emt conduit for $2.05 !

i was thinking that this would be as cheap if not cheaper than the 14 or 16 gauge speaker wire idea i had planned for the radials.

would the conduit work better ?

also, what would be better; 3 or 4 radials ??

Thanks !!

I would use four radials.

I built one with three before out of 10 ga copper wire used for home electrical.

But using conduit would be solid and stay straight.

The only trick is making the insulator in the middle.

Put it higher if you can; just guy rope it securely and it should work great.

I built one out of wire for demonstration purposes, and it worked just great.

Using the materials you suggest would make it solid and stand the test of time.

 

[ElectronTubesRule]

IF anyone use's PVC get the grey stuff it is rated for outdoors use and has UV blocking agents in it. If you white the sun and ozone will make it brittle fast meaning it will break at some point. I would cooper pipes for the radials if your are making rigid about ground radials.

 

[BOOTY MONSTER]

a pressure treated 2x4 works for a insulator .
a old fiberglass shovel handle workd too .

 

[522]

ok, im gonna scratch this idea. played around with a few things, and wow do i prefer the flat side more so than vertical.

since i do not have many locals to talk to, and prefer dx anyways, i will go with a horizontal dipole.

i am already working a home made dipole out of 12 gauge wire at roughly 7 feet, but next plan is to build another one out of emt conduit, and put it at roughly 20 ish feet.

thanks all for the input, and helping me make my decision.

horizontal dipole and mount is now in the design process.

 

[W5LZ]

Size of conductor for HF antennas is typically determined by how the antenna will be mounted. If the conductor will support it's self and the feed line, then it's large enough for use. Or, if the idea is to get some directionality, then rigid conductor of some type, tubing, certainly makes sense. That 'directionality' also will depend on the antenna's height above ground.
I've used wire antennas primarily for a lot of years. What size depends on what I happen to have on hand, or can get locally. In general, an insulated 14 gauge stranded wire will do just dandy. So would 18 gauge hard drawn wire, or 'Copperweld', it's just not available locally. There's no good reason to go larger unless you need a stronger wire for whatever reason.
When you consider the supports for that wire antenna, the average user isn't usually lucky enough to worry about too much height (if there is such a thing). The problem is usually getting enough height. 'More' is always better till it get's absolutely ridiculous, so, you do what you can with what you have available.
I think 'playing'/experimenting with antennas (especially wire ones) is fun. There are all sorts of factors that enter into that, and some really 'odd' antennas can work very well in particular instances.
Have fun.
- 'Doc

 

[Needle Bender]

ok, im gonna scratch this idea. played around with a few things, and wow do i prefer the flat side more so than vertical.

since i do not have many locals to talk to, and prefer dx anyways, i will go with a horizontal dipole.

i am already working a home made dipole out of 12 gauge wire at roughly 7 feet, but next plan is to build another one out of emt conduit, and put it at roughly 20 ish feet.

thanks all for the input, and helping me make my decision.

horizontal dipole and mount is now in the design process.

i talked to a guy 2200 miles from me on dx and he was alot stronger then everybody else and all he said he was running was a hundred watts and a single quad element with a 1/4 wave of 75 ohm coax right at the antenna to match it. he was real loud. maybe you could try that and go with the square so its olny 9 feet tall and wide if you can get away with it. you gotta feed the bottom middle for horizontle

 

[ElectronTubesRule]

Just a fun factoid about copper. THeir are roofs made out of copper in Europe that are 1000 years old and still working great. Once copper get's that green patina the process stops and the copper underneath is now sealed up tight from the environment. Unlike the oxidation of iron type materials copper stops once it has a nice green layer to it. So once it turns green could take years depending on the type of rain you have and the pollution in your area it stablizes and will last forever assuming it is strong enough to stand up to mechanical stress!

 

[ElectronTubesRule]

Wanted to add that I have known a lot of people that have trimed 102 inch whips to length for their A-99's they claimed they got less staic during storms and such.

 

[BOOTY MONSTER]

FWIU when copper corrodes on a ground rod it helps it further bond with the dirt/earth .
i wonder if a copper antenna corroding in the air will change its tuning or pick up reflections from the build up of oxide on the outside over time ?

 

[mackmobile43]

Wanted to add that I have known a lot of people that have trimed 102 inch whips to length for their A-99's they claimed they got less staic during storms and such.

Might be because by the addition of a stainless whip it also came to acquire and coronal ball?