Half-Dipole Antenna Question

I made a half-dipole antenna for my home stereo from wire scraps I had. It works fine, but unfortunately, my two favorite radio stations are geographically 90 degrees apart (East, and South). With the dipole being a directional antenna, that, of course, means sacrificing one station's signal for the other. Instead of dropping money on more equipment, can I just add a second half-dipole in series with the first, making the second in the same horizontal plane, but oriented 90 degrees from the first dipole? If the two dipoles are oriented 90 degrees apart, would the interference between the two dipoles be zero, allowing me to get maximum signal from both the East and Soputh?

Look up a "halo" antenna. It's omnidirectional, but flattens out the pattern, so has some gain over a dipole, but in all (horizontal) directions. It's also horizontally polarized.

You might also look for a "turnstile" antenna. That's typically two folded dipoles with a 1/4 wavelength transmission line connecting them, to give 90 degrees phase shift between the two antennas, making it omnidirectional.

But since you have a random-wire, just put two little cuphooks in the ceiling, and hang the loose end of your antenna from whichever one works.

Good Luck! Rich

I am pointing the dipole by it's broad side, unfortunately, both stations are marginal. When I turn the antenna to get a decent signal on one, the other is too poor for me to tolerate.

I will try this first.

My antenna is mounted in a large attic, so I don't have to worry about rot or space. If the vertical orientation doesn't help I will try a cubicle quad. (I may try to build one just for the heck of it.) Can you recommend a web-site that would have specs or drawings to construct one? I don't really know much about radio electronics.

Thanks to you and Larry for your assistance.

had. It

I think you may mean a half-wave dipole.

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No problem point half way in between, and of course you point a dipole by the broad side of it, not the ends. Like Larry said, you really shouldn't notice a problem unless the signal is very marginal since the

Antenna theory is just that, theory. Reality often stands a good distance from it.

I suggest you build yourself a two element cubical quad, or a two element beam. One of them will have so much more gain (hopefully without narrowing the beam width too much) than your dipole that you should have no trouble receiving both stations without re-pointing it. If you have the room for the 3-d nature of the cubical quad then I highly recommend you build one, you will be real happy with it. I once built an 8 element quad for VHF (2 mtrs) that really kicked serious butt, but it was a real bear to tune. Sadly, it was made from wood so nature eventually took it from me.

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You are not likely to have much luck with this kind of thing without learning a ton more than you probably want or care to know, but I could be wrong. The key is to experiment with antennas, you will be amazed at what works sometimes.

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By itself, a full wave loop will have about 3dB of gain vs. the dipole. In fact you may get good results by just using a full wave loop without the reflector. You should try that first and then add the reflector noting the effect it has on sensitivity (gain). Adding the reflector will give you a front and a back side.

You point a loop asif you are trying to have the signal pass straight thru the open hole. The optimal shape for a loop is a circle, but squares are usually more convenient and they work fine.

u might try a J-pole made from 300 ohm twin lead for your vertical project. I'd browse ham antenna sites for the calculations.... they're typically sized for the ham 2m band (approx 144mhz)