home made antenna question

[BOOTY MONSTER]

ok..... so im thinking of getting a small power supply and trying my mobile inside of the house . so ill be needing an antenna and rather than be smart and just purchase a 99 im thinking about trying my hand at building one . if i do that id like to try something a lil different .

theres knowledgable folks on both sides concerning the loss effect that a coil does or does not have on an antenna . lets by-pass that discussion and assume (i know i know :roll: ) right or wrong that its true . cutting to the chase im thinking of a 1 full wave antenna @ 11 meters . according to this site http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=254 One Wavelength for 27.405 is 35.906 feet . assuming , again , that i can make the parts and assemble the antenna and then tune the swr correctly would this antenna perform better than a 1/2 wave or 5/8 wave with the base of the antenna at the same height (30 feet) . im thinking it would because of the taller final height and the taller/longer radiating section . iwas thinking of using different diameter aluminum tubing for the construction material reducing the size as the antenna goes up .

am i onto something worth while with this or would i just be wasting my time and money ?

 

[Beetle]

I think you're going to find that the RF from a full-wavelength end-fed vertical will be going straight up. You might have a beautiful 1:1 SWR after you figure out a matching system, but that's no guarantee of anything.

However, you can experiment. That's how Mr. G. Marconi did things. Experiment and learn.

 

[W5LZ]

BOOTY MONSTER,
There's no simple answer, it depends on too many things. And you really don't say what 'shape/form' that full wave antenna is going to assume, vertical, horizontal, something in between, and so on.
Can a full wave antenna out perform a 1/4 or 1/2 wave antenna? Sure, under the right circumstances. Can a 1/4 or 1/2 wave antenna out perform a full wave? Same answer, sure, in the right circumstances. So, what exactly are you thinking about doing?
- 'Doc

(As for the the site you posted, there are some really 'odd' ideas there, some of which are not true and ain't gonna work, or are sort of silly.)

 

[Captain Kilowatt]

What Beetle said. There is a reason full wave verticles are not commercially made,even on VHF or UHF where size is not a problem.The really long verticles you do see for VHF/UHF are collinear verticles which are really like several half wave antennas stacked vertically.

 

[BOOTY MONSTER]

i was thinking just a straight verticle like an antron 99 or imax 2000 . i guess ill just find a inexpensive aluminum antenna like the Sigma/Alpha 5/8 . thanks folks .

 

[Seminoles]

The 5/8 wave is the top out of gain on an antenna from there to full wave it just doesn't get any higher also the 5/8 has the lowest take off angle better for shooting skip now then if you build a 3/1 wave that is different if you need something simple and easy to hide go with the I max 2000 want something good go metal something that will last I10k or similar or copper/silver plated rod and make a 5/8 wave dipole with the bottom element at a 20 degree tilt.

 

[W5LZ]

Just a comment about 'metal' antennas and those using something else.
First, all antennas are metal. That metal may be inside some fibreglass or whatever, but the radiating part of the antenna is still a conductor usually made of metal. Some very exotic thingys can/are made from some other conductor material besides metal, but they are very few and very far apart. If you ever see one for 27 Mhz, it'll really surprise me!
What's the difference between using a #14 gage wire and a 1 inch metal tube? Very little electrically. Mechanically there can be a big difference! As in, how do you stand a #14 gage wire on one end and not have it fall down? Any difference in usable bandwidth between the two is very little. That depends on the diameter of the conductor in relation to a wave length at the frequency in use. Difference between 1/16th of an inch and 1 inch in relation to roughly 36 feet? Forget it. Some, sure, but not enough to make -any- practical difference. (That 1 inch tubing is sure easier to make stand up though!)
Like the looks of a non-metal antenna, no problem, just paint the metal antenna white, or green, or 'hot-pink' (the 'hot -pink' works best!). Don't use paint containing metal or some other conductive stuff, doesn't work well, sort of.
- 'Doc