LC,
You might oughta wind the super hero's arm up another twist or two. Someone may want to whip up on you for mentioning height limits influencing design. Believe me, I know.
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New antenna from Sirio Gain-Master
- Thread starter dxswe
- Start date
LC,
You might oughta wind the super hero's arm up another twist or two. Someone may want to whip up on you for mentioning height limits influencing design. Believe me, I know.
lc, i have mentioned the same contradiction in the patent before,
i agree avanti desined the astroplane to make the most of fcc height restrictions,
you would have to test the astro at the same tip height to see if the patent claims are valid
i agree avanti desined the astroplane to make the most of fcc height restrictions,
you would have to test the astro at the same tip height to see if the patent claims are valid
Thanks Bob.
In case some can't get the US Patent Office Website to open the data windows try: http://www.google.com/patents?q=3587109 This will send you directly to the AstroPlane patent and doesn't require a special add-on to make it work. Just in case.
Google also seems to have more details about the patents and stuff related to some patents…when info is available.
Loosecannon said:
Loosecannon said:
LC, I can't remember specifically what the Patent said about the BW, but I do recall the Avanti raising the issue. I do SWR and Analyzer bandwidth curves on all my antennas and when I was testing the regular AP (old top one) and again a day or two latter with a full 1/4 wave radiator, I did it just because Avanti discussed it.
My VA1 BW curve on 8/1/09, with the full length radiator did have a skew in it at 27.205>, which made a big change in the curve, but I think it goes back to normal at about 28.005. This sometimes happens while I’m scanning over a broad range, and I usually don't notice it until I start to plot the curve on paper. Sometimes I record the data and don't do the graph until several hours or even days later. That said, I didn’t notice a big difference and that’s kinda’ what I was expecting...but not a dinky little difference like .22 mhz in favor of the full length radiator. I'm not even sure which direction the difference took between these two antenna designs referred to in the Patent. I could have even made a mistake in writing down the 1st and/or last frequency in one of the reports causing such a difference.
In my Signal Reports for that period… the full length did show a very modest advantage in average signals, but again there were only two reports, one for each, and that is not near enough to base any conclusions on. Also, I just looked at the raw numbers and did not analyze these two reports to see if there was more to be gleaned from a closer look. I just didn't see a BW difference with my VA1 and for sure the SWR BW curves look almost identical two days apart. I did notice the reactance on the full length AT showed all capacitive with x=0 at 27.205 mhz while the regular AP showed a mix of reactance starting a bit above 27.205 mhz.
My sense in operating these two antennas was that the full length model just didn't seem as responsive, even though the SR indicated it showed a bit more signal. Someday I want to compare again two Top Ones, side by side, one with a full 1/4 wave radiator and try and see if I can identify what that difference I perceived earlier really was.
I'm also working on a piece about my viewpoint for the issues concerning a 1/4 wave radiator and its proper ground plan as well, including how modeling predicts results of different configurations when the ground plane is effective or not. I also want to include how I compare the 1/4 wave relative to efficiency vs. effectiveness, and maybe try and explain how I see these two considerations differ, not to be corn'fused.
That could have been my bias for the Top Hat showing its ugly head however.
marconi, your analyzer findings at 27.205 are interesting.
it makes me curious to know what length of vertical radiator you used for the upper part.
102"?
108"?
i think that getting that length right so that the upper radiator is a true electrical 1/4 wavelength is important.
LC
it makes me curious to know what length of vertical radiator you used for the upper part.
102"?
108"?
i think that getting that length right so that the upper radiator is a true electrical 1/4 wavelength is important.
LC
I post here my Antenna Worksheets for the AP #1-3 and then #4 back to a regular A/P where:
#1, is set the full 1/4 wavelength element to what is, IMO, suggested in Avanti's manual for the AstroBeam @ 79.5", and it was way to short for some strange reason I have not figured out as yet...unless the added mount makes the element appear longer for the beam.
#2, was a guess based on a little math and it turned out to be too long, and
#3, I re-figured it at 87.5" for the 5/8" to 1/2" tubing and my curve shows the lowest SWR at 27.205.
#4, I set the antenna back to the regular AstroPlane.
The dip you see in #3 was an anomaly that happens sometimes...while I'm scanning and don't notice something is affecting the meter. I record the values I get and write them down, but I don't always plot the curve until later. Sometimes I don't realize this happening in the course of that process, and it shows up later when I plot the curve like noted above. In such cases I just imagine the analyzer curve being similar to the SWR curve...which I also run as a check for the condition of my antennas.
This process, though very slow and tedious, is like what Bob does with his MiniVa in a second.
LC, the fact that whips are 102"-108" for CB has nothing to do with this overall length for an element like the A/P which in my case was 5/8" & 1/2", with the top portion being the 45" x .5" top tube on my Sigma4 with 41" inches exposed. I hose-clamped this to the regular A/P radiator without the top hat. This diameter is 4-5 times the diameter for a typical whip and it will be shorter.
In the past when Starduster was doing his thing with his homemade A/P's he was about to try and test and verify this length for a full 1/4 wave on the A/P, but he disappeared and it never happened. I don't think anybody in this bunch will ever do this test either, so you'll just have to refer to my experiences on this count.
View attachment AstroPlane Bandwidth curve for full 1_4 wave.pdf
Well I've been running the Gain Master now for about a month and a half and though I haven't a thing to compare it to.
I must say it has lived up to what Sirio has said it would do.
It seems to smoke other antennas here in town and I have had great results talking long distance with it also.
The only two things I have heard to the negative side from the locals was it cost to much and it doesn't handle enough wattage.
My only reply to that has been, " I thought it was over priced until I tried it and now I fill it was worth every penny I paid for it.
As far as the wattage issue, I feel I don't need to run as many watts with this antenna so there ya go.
I must say it has lived up to what Sirio has said it would do.
It seems to smoke other antennas here in town and I have had great results talking long distance with it also.
The only two things I have heard to the negative side from the locals was it cost to much and it doesn't handle enough wattage.
My only reply to that has been, " I thought it was over priced until I tried it and now I fill it was worth every penny I paid for it.
As far as the wattage issue, I feel I don't need to run as many watts with this antenna so there ya go.
Well I've been running the Gain Master now for about a month and a half and though I haven't a thing to compare it to.
I must say it has lived up to what Sirio has said it would do.
It seems to smoke other antennas here in town and I have had great results talking long distance with it also.
The only two things I have heard to the negative side from the locals was it cost to much and it doesn't handle enough wattage.
My only reply to that has been, " I thought it was over priced until I tried it and now I fill it was worth every penny I paid for it.
As far as the wattage issue, I feel I don't need to run as many watts with this antenna so there ya go.
Good report okieBob, and I second every thing you said except the money part, but it is a weak argument for me to complain about. They should sell by the thousands and maybe more.
Hey Kamikaze I believe your observations, but that's a stretch unless you are running a a real nice beam or your buddies installed their GM's wrong. I'll bet their not too happy about that result. Maybe you should go down and help them get their installations right. I can see an occasional signal report favoring first one then the other, but not being heard or not hearing is not a characteristic result that I find when comparing my GM to any other antenna I have. Under a myriad of circumstances I might hear better on one then the other, but I don't believe I've ever experienced the GM loosing such a battle.
I'd bet some on this forum would be very interested to know what you're working that shows such obvious differences, unless maybe you're on double review probation.
Tell us more, about your experiences, like what were the conditions, distances, height of antennas, mode of operations, local or dx, etc..
op:If you can tell us what your neighbor's say about such a revolting development.
yes more info please
because it is possible if for example you are running a beam antenna at 70 feet to have better ears and line of site to another local station if the gain masters are only at 20 feet. but others will set me straight...
because it is possible if for example you are running a beam antenna at 70 feet to have better ears and line of site to another local station if the gain masters are only at 20 feet. but others will set me straight...
I don't know the setup details and I don't care. You just made my point.
People come on these forums talking about how great some new fangled gizmo is with zero scientific proof. I simply decided to do the same.
Unless testing is done on an antenna range under controlled conditions the test is next to useless. My story is useless too as you pointed out.
If I were on here telling everyone how great the new technology widgit was it might take 10 pages before someone came along to set the story straight.
BTW I really do outgun the two neighbors with far less power. Who knows why.......
People come on these forums talking about how great some new fangled gizmo is with zero scientific proof. I simply decided to do the same.
Unless testing is done on an antenna range under controlled conditions the test is next to useless. My story is useless too as you pointed out.
If I were on here telling everyone how great the new technology widgit was it might take 10 pages before someone came along to set the story straight.
BTW I really do outgun the two neighbors with far less power. Who knows why.......
Hey Kamikaze I believe your observations, but that's a stretch unless you are running a a real nice beam or your buddies installed their GM's wrong. I'll bet their not too happy about that result. Maybe you should go down and help them get their installations right. I can see an occasional signal report favoring first one then the other, but not being heard or not hearing is not a characteristic result that I find when comparing my GM to any other antenna I have. Under a myriad of circumstances I might hear better on one then the other, but I don't believe I've ever experienced the GM loosing such a battle.
I'd bet some on this forum would be very interested to know what you're working that shows such obvious differences, unless maybe you're on double review probation.
Tell us more, about your experiences, like what were the conditions, distances, height of antennas, mode of operations, local or dx, etc..
B
BOOTY MONSTER
Guest
of course its meaningful , knowing what it means is the key though . this gain master is certainly getting a lot of positive comments here from the smart cookies . but the asking price seems like an awful lot considering its basically just coax inside a fiberglass tube with a choke at the bottom .
Kamikaze , are you at a higher elevation than the folks with the gain masters ? a antenna on a hill will do better than antennas on a low area or valley .
My whole town is within 10 feet of similar height. My antenna is on a crankup tower and it works better than those guy's even cranked down.
Maybe they have crappy feedline or FOS about the power they are running.
I'm using a beam but it's only slightly better than my old vertical was. another non-scientific comparison.
Maybe they have crappy feedline or FOS about the power they are running.
I'm using a beam but it's only slightly better than my old vertical was. another non-scientific comparison.
B
BOOTY MONSTER
Guest
if you're saying that you're comparing a beam to their omni then yes , i would expect the beam would do better even considerably lower than the omni . if you're saying you have an omni doing better thats lower id be curious as to how much lower and what omni antenna you're using .