| Author |
Message |
    
Nightmarenyc
New member
Username: Nightmarenyc
Post Number: 1
Registered: 1-2005
| | Posted on Tuesday, January 25, 2005 - 11:18 am: | 
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OK guys, I've read the reveiews and everything and I know it basically boils down to 3 antennas. The Maco V5/8, CTE Top One, or Imax 2K. I live in NYC in a 4 story apt building and previously had the Maco and was very happy with the results, but it was freinds antenna and gave it back. The antenna will be on 20 feet of mast putting the feedpoint @ 60 feet. I'm looking for straightup performance. I know the TopOne performs great at lower heights but will it perform as well @ 60 feet? I'm not a big fan of fiberglass, but I see alot of you guys swear by the Imax so I's be willing to try it. Remember, I'm not looking for ease of installation, just straight up performance. I know the Maco will work, but the TopOne is cheaper. I'm using LMR 600 coax, everything is grounded to a 8' ground rod, and running about 500 watts also, so I don't want a bleedstick either. What do ya think? I'm kinda leaning towards the TopOne right now. Suggestions before I order?
Thanks! |
Twa77
Intermediate Member
Username: Twa77
Post Number: 133
Registered: 1-2003
| | Posted on Tuesday, January 25, 2005 - 3:41 pm: |
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maco 5/8 will work best for you. |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 171
Registered: 9-2004
| | Posted on Tuesday, January 25, 2005 - 4:22 pm: |
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i think the reasoning behind stating that the top one will outperform the others at less than a 30' feedpoint is because it is a top radiating antenna thereby giving you a 10' or so advantage. when you get your antenna more than 1 wavelength (36') above the ground the top radiation doesnt matter so much and the imax and the v5/8 can now do their jobs properly. since you are worried about bleedover i would suggest the maco v5/8. at the height you are putting it at, it will perform suberbly, have a great bandwidth, it wont bleed if installed correctly, (unless your limiter is clipped; then nothing will help.) as for lightning protection: you should pay close attention to this area as you could end up liable for other apartments' damage if your antenna takes a hit. im sure some of the techs on here can give you better advice about that than i can. BTW, how are you going to connect the bottom of your mast to the 8 foot ground rod? if you are planning on using the rad shak special aluminum ground wire think again. 4 stories is a LONG ground wire. the wire you use should be about as big around as your mast. not very practical i know, but safety is a big concern with this type of installation.
matt |
Pig040
Advanced Member
Username: Pig040
Post Number: 657
Registered: 7-2003
| | Posted on Wednesday, January 26, 2005 - 10:50 am: |
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V 5/8ths out of those three for sure!
Good luck with your station.
Rich |
Tech833
Moderator
Username: Tech833
Post Number: 968
Registered: 8-2002
| | Posted on Wednesday, January 26, 2005 - 7:19 pm: |
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Maco V-5/8. |
Tech291
Moderator
Username: Tech291
Post Number: 52
Registered: 11-2004
| | Posted on Wednesday, January 26, 2005 - 7:27 pm: |
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I'll second that.V-58
tech291
CEF#291
kc8zpj |
Mikefromms
Intermediate Member
Username: Mikefromms
Post Number: 394
Registered: 6-2003
| | Posted on Wednesday, January 26, 2005 - 10:05 pm: |
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You will own an Imax 2000 one day. Wait and see....
Mikefromms
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Airplane1
Intermediate Member
Username: Airplane1
Post Number: 270
Registered: 5-2004
| | Posted on Thursday, January 27, 2005 - 9:23 am: |
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MaCo V 5/8,you will be very happy, I am.
airplane |
Pig040
Advanced Member
Username: Pig040
Post Number: 658
Registered: 7-2003
| | Posted on Thursday, January 27, 2005 - 9:58 am: |
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Not if he uses the V 5/8ths, he wont, that is a fine antenna. Not downing the Imax, but it sure is scary to watch it wave around up there!
Rich |
Marconi
Intermediate Member
Username: Marconi
Post Number: 334
Registered: 11-2001
| | Posted on Friday, January 28, 2005 - 11:50 am: |
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If the V5/8 worked out well with the power before. I would say, why question a winner.
I hate to throw water on ya', but in your very populated situation, I think you are bound to get into somebody's business somewhere, plus it appears that you live in a very tight (four stories, 40 feet high???) spaced building.
With 500 watts, I believe your handle will fit the bill quite nicely with your neighbors.
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Nightmarenyc
New member
Username: Nightmarenyc
Post Number: 3
Registered: 1-2005
| | Posted on Friday, January 28, 2005 - 10:01 pm: |
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Thanks guys for all the replies. I had excellent results with the Maco when I had it up and believe it or not running everything wide open, NO TVI! This is why I went overboard with the coax in the 1st place. I have an 80 ft run of 2/0 wire to the ground rod in which all my equipment is grounded to also.. I know the Maco is rated @ 5 db gain as the Top One is 4.5 db so I was wondering if there would be really that much of difference.I agree with you also Marconi. The Maco was always a winner in my book,just wanted to see what all the "hype"was about with the other antennas is all. Oh, and I screwed up, it's actually a 3 story building and the extra level leading to the roof would be 40 feet. I currently put up a M104 which works great for dx but sucks for local talking. Thanks again guys, looks like I'll be ordering another MAco! |
Ferd1605
New member
Username: Ferd1605
Post Number: 6
Registered: 1-2005
| | Posted on Sunday, January 30, 2005 - 3:40 am: |
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here is an idea , i did it and worked AWSOME ... a V 5/8 .. do not put the radials at the antenna feed point , instead 5/8 wave BELOW .. then , put another 4 radials 1/4 wave below that , and have the coax inside the mast . that will { to make it simple} give you a marconi , or 2 5/8 antennas . it don't give you any more gain , but lowers the angle of radiation way down to almost zero .. great for ground wave , but could hurt you on state side DX but would kick butt on long haul DX like oveseas type stuff if the band ever picks up again . Like i said , i did it , and work stations over 180 miles on ground wave with no amp or beam. |
Marconi
Intermediate Member
Username: Marconi
Post Number: 339
Registered: 11-2001
| | Posted on Sunday, January 30, 2005 - 10:46 am: |
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Old Marconi also had a grandious thought at one time that if he could just find the right soil conditions, surrounded by sea water, on a mountain or hill higher that everything else, get his antenna up as high as possible above even that, and making the AT as big as he could, would make for the best radio work possible. After a while experience with efficency and affectivness in his thinking caused him to change his mind. All the factor remained important considerations, but they just didn't always seem to work too good when combined as he originally thought.
IMO, moving the ground plane that far away from the device that is trying to resonant the V5/8 radiator would render the match unworkable, because you would have a lot of resistance to deal with and you would loose control over the reactance at the feed point. Getting the coax inside the mast somehow might help decouple the coax, but I doubt that your idea would work as you say and for sure would not be so simple.
Otherwise I think you know what you are talking about. Sounds good though. Do you grin as you type?
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Tech833
Moderator
Username: Tech833
Post Number: 980
Registered: 8-2002
| | Posted on Sunday, January 30, 2005 - 11:02 am: |
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If you ran the coax through the mast, you have created a 'bazooka' decoupling transformer. As long as the decoupling sleeve is at least 1/8 wave, you have it. A 1/4 wave mast decoupling sleeve would be your best bet. Anything more than that is sorta ineffective.
Monting the 1/4 wave ground planes that far below the feedpoint is inadviseable. |
Ferd1605
New member
Username: Ferd1605
Post Number: 7
Registered: 1-2005
| | Posted on Tuesday, February 01, 2005 - 4:12 am: |
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Humm , ya all must not like the stuff i have seen in some antenna hand books .. but any way , another i have tried and worked good which at this time can't find my files on is a 11 meter version of the old isoploe VHF and UHV antenna . instead of using solid sheet of metal , i used several wires with PVC tubing on the mast to hook them to along with wires horizontal spaced about 2 feet apart to enhance the skin effect to simulate solid sheets. {hope ya get my drift here} Hard to explain here how it looked after i built it , but it was basicly the same thing as my last post .. Also , i seen a website for antenna and seen a guy use 8 radials all 5/8 wave long dropped down at a steep angle. he used a antenna desighn software that showed a 1 deg. angle of radiation .. think i may try that someday .. |
Tech833
Moderator
Username: Tech833
Post Number: 984
Registered: 8-2002
| | Posted on Tuesday, February 01, 2005 - 9:58 am: |
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Ferd,
That isopole design is basically what the 'Skylab' antenna does. The difference is that there are more ground planes (in your case) or a solid conductor in the mfg. version.
Nonetheless, it is still a modified ground plane dipole. If you get the ground planes down to the point they are inline witht he top element, you have a coaxial dipole. |
