Base Antennas: Is one enough? WARNING: TOPIC IS 2 BEERS LONG

[drdx]

My tree antenna deal brought this deal to mind. I often see on here mention of a base antenna, how high and which one. What I don’t often see is mention of having more than one. Picture your station as a box of tools, and the antenna is a tool. We’ll say it’s a screwdriver. Now in our garage or wherever, we all have a box of tools, but do we all just have one screwdriver? No, we don’t. We have several, long, short, Phillips, slotted, torx, as there are different types of screws and one size does not’t fit all. So, why only have one antenna?

Polarization: Many out there are running a set of beams and know the benefits of “going to the flat side”. I remember the first time I had both a vertical and a horizontal wire antenna. I was astonished at the difference in changing antennas. It sounded like I had changed channels or something. Signals that were strong on the vertical dropped in strength when I went to the wire (due to the up to 20db cross polarization difference in signal) and other signals replaced them that I didn’t know were there. Skip comes in randomly, but often one polarity will be better than the other. That holds true today, and you don’t have to have a large expensive setup to get some of that benefit. Sure, having both in the form of a large directional beam is nice, but not attainable by all, and a beam doesn’t always lend itself to be the best choice, as in the case of local talking to stations in different directions, or the popular “locking down the town. Do you and a buddy like to talk locally, but have to fight through the crud of other locals? Go flat.

Height: I see this posted all the time. “How high bla bla bla to be able to blank blank?”. Well, on the local scene, height is the key, and it helps in the TVI department too. At minimum, you need to be in the 18 ft or better range. I read somewhere that optimum height for a beam is between 1 and 3 wavelengths, and above that is thought to be too high. This was in reference to skip, not local. I also see on here “height is might” and for skip it doesn’t matter. Well, it all matters and has an effect on signal. As the height of the antenna varies, the angles at which it radiates varies. Verticals, typically, are a good way of getting a nice low angle of radiation, and a low dipole, in general, will give high angles when very low. Angles, both high and low, have their benefits, but it pays to figure out what is best for your style of operation. Lots of things will work, but they don’t all work well, and none of them please all needs to an optimum level. Keep that in mind, as an antenna that is extremely high will have much lower radiation angles, and you can get to where the antenna radiates most of its signal so low it overshoots your desired area. You might be wanting to shoot skip here domestically, but having it too high makes the domestic stuff a little watery, and pulls in the far off stuff, like the Spanish speaking south Americans, or the Europeans that you may or may not want to hear. Conversely, an antenna that is too low may do fine for domestic skip, but lack in the European and Australia department. This is just general talk here, and I do realize that antennas do vary in these qualities, so this is not a one size fits all deal.

If you are a one antenna base, throw yourself up a cheap home brew dipole, and see for yourself. If you have a skyscraping skyhook, throw up something low. How about a sloper, or a multi sloper that can be directional? Phased array?A loop maybe? What about a DDRR, a V-Beam if you have the room, or a giant discone?? How about a fixed wire beam to the area of the world you talk skip the most? I’m even thinking of a low noise underground loop.

Just think how handicapped you’d be in the garage if you only had that one flatheaded screwdriver, and apply that thinking to your station. This tool theory applies to amps, radios, and other items as well. Make mine the 500 piece master craftsman variety, and I’ll still be spending money in the tool aisle, as you can never have enough. -drdx

[busman]

:D :D :D I LOVE THIS FORUM. :D :D :D

[BigBlue 442]

I think you have just completed the formula: CB=(constantly buying)¥

I agree totally.

[80 meter man]

Antennas are just like radios---One is never enough----

[AK295]

I agree I agree I agree !!!

My wife always ask if I'm in search of ET or something!

Two beams, two ground planes, and three sat dishes !! I'm out there listening alright!

[bullet]

A now there is hunk of thinking right there. I will need to check this out do you think the wife will go for it??

[Mojoe]

Freedom of choice is a wonderful thing!


On the left, M106 vertical. On the right, IMax 2000 with an M105 mounted flat, acting as a ground plane kit when not in use. Having variety is really nice.
Later,
Mojoe :D

[hippieman556]

i am still not sure what works best for local talking any help

[bullet]

DRDX
How is that antenna your were building on the ground. Not the tree the other one in a gray pvc and the gamma match. Is that coming together ok for you.
I think I will put up a dipole. I heard they are good for skip. It is not good for truckers.
What would be best for skip a slope, inverted v or just the good old horz.

[drdx]

Well, I have it in my side yard, and it matches well, but it is too big for my taste there. I'm putting it in the attic in a large area 25 ft or so from ground that is open and free of attic debris. I'll run another bare wire one outside most likely. I haven't had much time to mess with it, as I'm focusing on getting the mobile all improved, but that's where I'm at.

I'd do a horizontal dipole if you already have a good vertical, as it is a good antenna at the other polarization extreme.

-drdx