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astrobeam

Interesting reading the advertising . The lighthouse reference brings up a few dated questions . How do they claim it radiates from the top When fed in the center one side of the lower element is the feed point down to the ring at the bottom and back up to the boom on opposite side to ground at the boom. the upper half of the driven element is grounded . so where is the highest current distribution.as for the 40 DB rejection i doubt it just typical advertising hype from 70's 80's but we have never seen that before have we ? over all a good antenna i would compare it to a standard 3 ele vertical . they seem to work good locally up to 40-50 miles and i believe due to the design had more signal on the ground is the reason

RCB
 
BM, over the years I've heard mush of the manufactures hype and have seen and heard user's reports. Along with my understanding of how testing and comparing goes in the real world...I'm not inclined to believe anything or anybody any more, unless they show some effort and work to support what comes out of their mouth.

I say, if you can't show some effort in testing the ideas you present with your words, then what is there to believe. Most don't believe the stuff I post, and I show more results than just about anybody I know on these forums. Even with all the tools we have today to do some testing, hardly anyone goes to the trouble and if they do, too few will talk about their own work without getting pissed off first. So, what is the big deal posting or reading all the BS posted about antennas, if it is all hype and BS.

That said, the big advantage from almost all who talk about their experience with this A/P beam is...that it works pretty good and has great rejection. So who do we believe.

So BM, why show stuff we don't believe?
 
regencycb said:
Interesting reading the advertising . The lighthouse reference brings up a few dated questions . How do they claim it radiates from the top When fed in the center one side of the lower element is the feed point down to the ring at the bottom and back up to the boom on opposite side to ground at the boom. the upper half of the driven element is grounded . so where is the highest current distribution.as for the 40 DB rejection i doubt it just typical advertising hype from 70's 80's but we have never seen that before have we ? over all a good antenna i would compare it to a standard 3 ele vertical . they seem to work good locally up to 40-50 miles and i believe due to the design had more signal on the ground is the reason

RCB
Click to expand...

I may be pretty much alone in my praises for the seldom used and talked about A/P idea, but regencycb is pretty much right.

If the major portion of the A/P is about 8' feet below the feed point, that takes some of the advantage away from the gain in performance for the Top Hat idea in principal...raising the current distribution.

I do find, however, if one gets the A/P or the Old/New Top One up as high to the base of other CB vertical antennas, it will preform very well when compared, albeit has a tip height that is often much lower.
 
sorry if my post ruffled your feathers marconi . i was just making a on topic reply and comment about the specs of the antenna . work and effort is no doubt a powerful thing .... as long as it's done correctly and it can be duplicated in a good majority of real world installations . IMO .
 
homer , do you think your tuning method for the astroplane would work on the astroplane ?
 
BOOTY MONSTER said:
homer , do you think your tuning method for the astroplane would work on the astroplane ?
Click to expand...

BM, in case you're having a problem remembering, I believe that is what Homer has said. The Avanti Patent also suggested that is what tunes the A/P and I have no reason to disbelieve that even now.

What I told Homer was, when I modeled the A/P I could get the antenna much closer to tune with the proper dimensions that I used, but I could not change the center frequency by making similar changes like he did. I was surprised at the results however, and I've said as much.

Another time that I saw the resonant frequency change with my Top One was when I first tried changing the Top Hat element to a full 1/4 wave element. On considering what I should do to start this project I decided to use the recommended length of 77" inches that is noted in the AstroBeam manual. That turned out wrong and put me in 28 mhz. Here are the Antenna Work Sheets for that project for tuning. Sorry I notice that I posted these in reverse order, but the reports are numbered at the top left side of page.

View attachment AstroPlane tuning for full .25 wave tip..pdf

I would show you the models and try and convince you further BM, but you don't understand a whit about modeling.

If you guys knew how simple getting started in Eznec5 modeling really is, you would all be kicking yourselves. Some have a mental block that they'll never get it, and that is all that is stopping most of you, and some have a block that says modeling is a worthless effort.

BM, I know why you posted the ads, you're famous for doing such. I was just making a point about the credibility problems posting manufacturer's hype that no body believes.
 
My biggest mental blocks to using modeling are simply two:

1. actually a wallet block - the full versions cost $$
2. I could be in the yard making an antenna while I'm in the shack modeling one.

I also have a buddy goes by OGP, or Marconi who will model for me if I ask . . .

;)
 
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Marconi said:
I would show you the models and try and convince you further BM, but you don't understand a whit about modeling.

If you guys knew how simple getting started in Eznec5 modeling really is, you would all be kicking yourselves. Some have a mental block that they'll never get it, and that is all that is stopping most of you, and some have a block that says modeling is a worthless effort.

BM, I know why you posted the ads, you're famous for doing such. I was just making a point about the credibility problems posting manufacturer's hype that no body believes.
Click to expand...

since eznec5 is so conclusive and you're so proficient at it why don't you save everyone everywhere from wondering what antenna is better than all the rest so everyone can just buy that one antenna ????

and i don't know why you have been badgering me lately .... unless it's just because i'm not thrilled by your antenna simulations . but if you have a problem with me you are welcome to discuss it it here , in a PM or you're more than welcome to call me if you still have my number .
 
BOOTY MONSTER said:
since eznec5 is so conclusive and you're so proficient at it why don't you save everyone everywhere from wondering what antenna is better than all the rest so everyone can just buy that one antenna ????
Click to expand...

BM, I make no specific claims about my models. If anything I might suggest a trend response to be noted. If you understood anything at all, you should understand that in my real world experiences and my modeling experiences that I have posted, I see about the same results with all the CB antennas I have...given that they're fairly compared.

BOOTY MONSTER said:
and i don't know why you have been badgering me lately .... unless it's just because i'm not thrilled by your antenna simulations . but if you have a problem with me you are welcome to discuss it it here , in a PM or you're more than welcome to call me if you still have my number .
Click to expand...

In this case, I've already explained why I posted my comments. I'm not trying to badger you, I may be trying to get you to consider another point of view. If you have a question about any model that comes to your mind, why not try and ask your question. If I still have the model, who knows, I might agree with you in some cases or explain as best I can?
 
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I just use simple wire antennas based upon age old designs. Seems like our predecessors made out just fine without futuristic computer modeling.

It's a tool and I understand the concept, but I am not looking, nor do I need the holy grail of antenna designs to satisfy my creative endeavors whilst stringing up a simple wire.
 
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There is no "Silver Bullet" when it comes to antennas.

Each antenna is a compromise in some way or another, except the 1/4 wl ground plane.

The 1/4 wl GP is as basic as it gets and it does perform rather well.


Everyone seems hung up on TOA,, If you want a lower TAO then install the 1/4wl GP higher above ground. Height of installation also effects TAO.


It is amusing to read all the threads about the .625 and the .64 wl but both require matching networks etc etc, matching networks mean losses, look at the Imax 2000, that thing covers 21mhz to 29 mhz,, talk about lossy as all get out.

You wont find a 1/4 wl GP covering that much freq on band width, means the 1/4 wl is more efficient.
 
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