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Marconi
Intermediate Member
Username: Marconi
Post Number: 379
Registered: 11-2001
| | Posted on Saturday, February 19, 2005 - 10:50 am: | 
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OK guys, I think I got my idea of this Astro Plane thing nailed down now.
First off I believe that it is likely this antenna will show as good or better results when compared to another vertical ground plane where both the tip heights are equal. This is probably so, because the point of maximum radiation in the AP will be somewhat higher than the other antenna by design. It is just a physical thing having to do with tip height and the top load feature in the AP. That is likely elementary and simple.
It is also probably true that the AP will perform as well or better when installed with the bottom hoop just 8’ or so off the ground when compared to another vertical ground plane antenna mounted with the feed point at 8’. If the feed points are at equal heights then the traditional ground plane will probably perform best because the point of maximum radiation for the traditional will be higher. There maybe other factors about better take off angle and such, but I cannot determine those issues.
My conclusion is that the AP is not limited to being efficient only at some relatively low height. If a regular GP works better due to an increase in height at some location, then an AP should show a similar improvement under the same conditions while assuming an equal tip height.
The patent repeats a condition for optimum performance in the original design several times. It states; “…best performance is obtained when the supporting mast (14) projects below the lower hoop by a ¼-wavelength.” This caused us to think that it was necessary to maintain that length or the performance would suffer. If that was true, and it was not true, then that would mean that you either had to install this one at very low height (18’ to the hub), or you would cause the antenna to produce a higher angle of departure (TO angle). Or if you raised it up, making the mast longer than ½-wavelength, then that was a no-no as well because the ½-wavelength long rule would be eliminated. Well, the patent paper also state that support mast 14 may as well be non-conductive if the coax is dressed properly down the non-conductive support. So that meant that the antenna would use the coax shield to do what it needs in order to match.
Well of course the original though we had was that the mast needing to be conductive and to be maintained at only ½-wavelength in order to work best or the performance was out the window, so-to-speak. That was wrong, like the height limit for this one was wrong.
So raise that bugger up there and let her work.
I have gone back to my original theory of a long time ago that concludes, if the AP does not appear to respond to local vertical receive signals quite as well as another vertical nearby and at a similar tip height, then it might be due to the remarkable horizontal responses that the AP seems to make. I believe this is proved out by the fact that generally they are said to work DX beautifully at a variety of heights.
I have also compared this antenna against other verticals, using a horizontal as the bases for comparison, and I found the AP seems to respond well in those experiments. Admittedly they were not scientifically done, but we did notice very good horizontal responses every time from at least two AP’s at the same time.
Maybe it ain’t nothing new or revolutionary, but I still don’t believe all the bad rap that the AP has received about working only at limited heights.
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Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 219
Registered: 9-2004
| | Posted on Sunday, February 20, 2005 - 1:58 am: |
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marconi, i just spent the last hour typing in a very detailed response to your post, and with one flick of the wrist, i accidently bumped some key that took me to the troubleshooting page. and as you all know, if you go to a new screen while inputing your post, the back button will erase all your hard work. i am so completely bummed right now. it was a good post too. i just dont have the heart to retype all that precious data right now, so here's the short version. (BTW, i now hate internet explorer). i took the text you mention to mean that the ring should be a minimum of 8 1/2 feet above the earth or any other obstruction. after that, i dont know how much the mast length affects the performance. i am putting mine at 25 1/2 feet to the ring which is 3/4 wavelength.
i'll type more tomorrow. sorry, but im too mad to go on.
matt |
Marconi
Intermediate Member
Username: Marconi
Post Number: 381
Registered: 11-2001
| | Posted on Sunday, February 20, 2005 - 11:21 am: |
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Your right Kid, I guess all of us have had that happen before.
After all of this, I believe the antenna will work fine even if it has no mast at all. The patent says the AP will use the coax as long as it has the proper spacing between the other elements and if it exits the bottom hoop by at least 1/4 wave length it will work fine.
Put it at any height and it will probably work just as good as any other, as long as the tips are about the same height.
I know they are quite compared to fiberglass antennas, so that should be a plus and you know what I think about their working DX.
Good luck |
Marconi
Intermediate Member
Username: Marconi
Post Number: 382
Registered: 11-2001
| | Posted on Sunday, February 20, 2005 - 11:47 am: |
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BTW Kid, regarding what I said about no mast above. That is not a recomendation, it is just what is said in the patent. |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 220
Registered: 9-2004
| | Posted on Sunday, February 20, 2005 - 9:04 pm: |
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yeah, i dont have a tall enough crane to hang it from anyway. LOL
im feeling a little more verbose than last night so, here are my thoughts on the comparisons between the top one and the 1/2 wave and 5/8 wave type antennas.
to me, it seems that the reasoning behind the claims that the top one will outperform the alpha 5/8 wave when the mast is less than 30 feet tall, and that the alpha 5/8 wave will outperform the top one when the mst is taller than 30 feet, is that the 5/8 wave type vertical radiator is a more efficient antenna design than whatever type the top one is, BUT the 5/8 wave type antenna wont perform correctly until you get the base of the antenna above 30 feet above ground. (man that was a long sentence!)
i dont know if the length of the mast below the ring on the top one matters, but im putting mine at 3/4 wavelength.
im also upgrading mine a bit, and i recommend everyone do these to your antenna before you put it up in the air. i am not an antenna theorist, but i do know metal, and physics. (metalphysics?)
the bolts and nuts that come with the top one are passable at best. they are also metric and a little off-sized. drill out all the holes in the aluminum and the plastic with a 17/64" drill bit. then go to the hardware store and buy 1/4" X 20 stainless steel bolts one inch long. then buy 1/4" nylock nuts; these have a nylon ring inside them to keep the nut from vibrating loose.
go outside and shake the mast of your top one. you will see the ring bounce back and forth.
there is quite a bit of leverage applied to the mast support mid way up the antenna. i recommend using some sort of UV resistant non metallic tie line to the ring and around the mast in four directions so that the ring is tensioned against moving against the mast. i love this antenna!
matt |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 221
Registered: 9-2004
| | Posted on Monday, February 21, 2005 - 1:06 am: |
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wow, i change my mind faster than i change my socks! then again i am a cb'er so changing my socks is more of a seasonal thing. J/K
anyway, i have decided to raise the antenna higher and use guy wires. im going with a 49 1/2 foot mast. which is five 10 foot masts driven 6 inches into the ground. this will leave 42 1/2 feet from the ring to the ground, which is 1 1/4 wavelength above ground. i will guy it at about 30 feet with nylon guy wires. this will be the highest i have ever installed an antenna and i cant wait. there is only one drawback to having an antenna way up in the air. you have to watch what you say because you are easy to find! LOL
matt |
Marconi
Intermediate Member
Username: Marconi
Post Number: 385
Registered: 11-2001
| | Posted on Tuesday, February 22, 2005 - 3:16 pm: |
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Good luck Kid. Be very careful, those 10' mast things can be pretty wobbly until secured. Securing the top is important, but don't overlook how a wobble below 30' can develop if the tip get to working in the wind. IMO, one set of guys is not enough. How are you going to get that thing to rise? Make sure if it does fall that it won't reach over to the neighbors.
You must watch out for power lines with that thing. If you do get it up you may also find it just as difficult, or more so, to getting it down.
They go up pretty slowly, but they tend to come down pretty rapidly. Make sure the AT is working right, before going up.
Those mast don't tend to last too long sitting on the ground. See if there is another way? Besides that it sound like you are going to have to stab the longer section into the bottom section that you have hammered into the ground. How is that going to work without a lift bucket?
Think about it. Even a 50' pushup can be a problem and you aren't going to be able to do that. Sounds like a real challenge to me using five 10' masts.
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Road_warrior
Intermediate Member
Username: Road_warrior
Post Number: 305
Registered: 7-2004
| | Posted on Tuesday, February 22, 2005 - 5:03 pm: |
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I'm curious to see how the Top One performs
at that height. Keep us updated Kid-V.
Thanks
JIM/CENTRAL PA/CEF 375 |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 223
Registered: 9-2004
| | Posted on Tuesday, February 22, 2005 - 11:10 pm: |
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you got it road warrior, i have the antenna 25' off the ground now and have written down the signal strengths of all the guys in my neighborhood. (20 mile radius).
marconi, i'll give you the details of my installation and let you lend your advice.
the mast is going to be mounted to the peak of the eves of the house. the peak of the house is at about 15 feet. i will be using an eve mount with two clamp points on the mast.
first, i will put two sections together and clamp them in the eve mount. with the antenna in two pieces, separated at the middle support bolts; i will mount the top half to the top of the mast, and attatch the coax. then i will push the masts up another five feet or so, tighten the eve mounts, and attatch the bottom half of the antenna. (making sure to use nylon ties to support the ring.) then i will push the masts up just enough to fit another 10 foot section underneath. i will then raise them up enough to mount the guy ring which will be about 18 feet down from the top of the mast. i will attatch lengths of nylon guy wire to the guy ring, then i will raise all this up again just enough to add another 10 foot section underneath, and then i'll repeat this step one more time. the secret is to loosen the eve mount clamps just enough to allow the masts to slide freely, pulling the masts up, and sliding in the next lower section. i always choose a very calm day for an antenna mounting party. the guy wires will be attatched to the house and to the cinderblock wall. the mast sections will have the paint ground off of them where the sections meet, and will be screwed together for extra support. the base of my mast will be a five gallon bucket buried level with the earth. the mast will be cemented in 6 inches down. i will be attatching an 8 foot ground rod at the base of the mast. so what do you think?
matt |
Marconi
Intermediate Member
Username: Marconi
Post Number: 389
Registered: 11-2001
| | Posted on Wednesday, February 23, 2005 - 12:17 am: |
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You have been using your head and planning is beautiful. I don't like the use of more than two of these mast together, but if it works what's the dif. Seems like a nice pushup pole would be cheaper in the long run.
The base idea is better than 6" in the dirt.
Maybe consider at least one more set of guys.
Watch out for the look of the coyote while your up there, OK?
Be careful and good luck. |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 224
Registered: 9-2004
| | Posted on Wednesday, February 23, 2005 - 3:55 pm: |
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ha! i like the way you think marconi.
i will definitely think about adding a second set of guys. its not much more money and wouldnt be too tough to do.
i have always wanted a 50' push up pole, but ive already got these 10 foot masts. i will do some local searching and see if i can find one. the shipping would be the killer for me.
thanks for all the input. if all goes well, i will be doing this on friday. that is if my coax shows up by then. i cant wait to post the results. i will call the post "top one at 54 feet".(that will be to the tip approx.)
matt |
1861
Member
Username: 1861
Post Number: 86
Registered: 2-2004
| | Posted on Wednesday, February 23, 2005 - 6:14 pm: |
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I AM ANXIOUS TO SEE HOW MUCH DIFFERENCE YOU SEE WITH THE ADDITIONAL HEIGHT . IF IT IS SUBSTANTIAL , I WILL PROBABLY RAISE MINE . |
26_op_141
New member
Username: 26_op_141
Post Number: 6
Registered: 2-2005
| | Posted on Thursday, February 24, 2005 - 10:11 am: |
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For all those who want a better TOP ONE. Tell copper you want them to import the Tagra BT-101 from Spain. It has a far superior strength to the Italian Top One and is Gold anonodized to resist corrosion. Ive had mine for 20 years and the gold is still intact and constrution is the same as when I bought it. Its actually made better than the US Avanti Astoplane:
73
Tim
26 Orient Pirate 141 |
Marconi
Intermediate Member
Username: Marconi
Post Number: 393
Registered: 11-2001
| | Posted on Thursday, February 24, 2005 - 11:13 am: |
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Orient Pirate 141, how high do you have your antenna? What is your opinion of how it works for you? Have you raised or lowered yours to see if that makes any difference? |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 232
Registered: 9-2004
| | Posted on Thursday, February 24, 2005 - 10:33 pm: |
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youre a funny guy marconi! you'll keep 'em on track! how dare they hijack our thread!
im just kidding guys. i have read about the Targa before. im curious as to the details of how you aquired it. did you have to pay international shipping? what was your total cost to get this antenna to your door?
matt |
26_op_141
New member
Username: 26_op_141
Post Number: 9
Registered: 2-2005
| | Posted on Wednesday, March 09, 2005 - 11:45 am: |
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Marconi;
I had the Tagra BT101 (topone) at 30' above ground at its feed point. It works real well.I have never tried it at different heights though.However I have just replaced it with a Shakespeare NBS2010 and the SS seems to be up on the top one performance.
Kid vicious:
Im in England they imported lots of tagra stuff here many years ago. The factory in Spain is still making the Tagra BT101 for sure. Just type in TAGRA NET in google and you will find it. Im sure it will be more expensive than the Italian Top One but I assure you that quality is 80% better.
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