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Message |
    
Johncalifornia
New member
Username: Johncalifornia
Post Number: 4
Registered: 9-2004
| | Posted on Thursday, April 28, 2005 - 3:50 am: | 
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My Maco 5/8 showed up today, I wasn't too impressed with the quality of the machining... looks like they needed to slow down a bit on the assembly line. I really do like the looks of the antenna, and all in all I think it is going to do really well. My Penetrator 500 is getting old so I'm retiring it. Now here is my silly question...
After assembling and taking a close look I noticed that the wire coming from the center lead on of the so-239 is connected to the ring, and the ring is directly connected to the outside of the so-239, there is only about 12 inches of copper and aluminum connecting the two.
How in the heck can this design work? Won't this cause swr's to skyrocket and burn up the radio?
I don't see how this is any different then simply taking a 12" piece if wire and jumping it from the center lead of coax to the outside shield?
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Mrbigshot
Member
Username: Mrbigshot
Post Number: 59
Registered: 2-2005
| | Posted on Thursday, April 28, 2005 - 8:43 am: |
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it doesnt cause a problem for rf (supposedly) solarcons are the sameway. at least thats what they told me. |
Airplane1
Intermediate Member
Username: Airplane1
Post Number: 395
Registered: 5-2004
| | Posted on Thursday, April 28, 2005 - 8:44 am: |
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It works and very well, mine my SWRs are 1.1-1.2 across the band.
You will like it and it holds up very well in high winds. |
Road_warrior
Advanced Member
Username: Road_warrior
Post Number: 517
Registered: 7-2004
| | Posted on Thursday, April 28, 2005 - 9:25 am: |
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Just follow the directions and the V-5/8
will work fine for you.
Maco keeps the price of there antennas down
by not cleaning up all the burrs and rough
edges on the parts.
A file and some sandpaper will easily take
care of this, so, the parts go together
correctly.
JIM/ PA/ CEF 375 |
Road_warrior
Advanced Member
Username: Road_warrior
Post Number: 518
Registered: 7-2004
| | Posted on Thursday, April 28, 2005 - 9:44 am: |
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Also go to the Subscriber (preview) section
of the forum, click on articles and scroll
until you find "Do Aluminum Antennas need
time to settle"
Good article on essembling metal antennas.
JIM/ PA/ CEF 375 |
Airplane1
Intermediate Member
Username: Airplane1
Post Number: 397
Registered: 5-2004
| | Posted on Thursday, April 28, 2005 - 11:08 am: |
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Very good points RW, I did what it says in the artical on (do aluminum antennas need to settle)
and am very happy wiyh the outcome. I did`nt clean up the edges though, no one sees it up in the air anyway and mine went together great just the way it came.
RW likes his alot too, So will you.
AP |
Johncalifornia
New member
Username: Johncalifornia
Post Number: 5
Registered: 9-2004
| | Posted on Thursday, April 28, 2005 - 11:14 am: |
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Thanks for the quick replies, don't get me wrong.. I'm not putting this antenna down, and what Road Warrior said about keeping the price down made perfect since. It is a whole lot of antenna for the price tag, and I have a good feeling that it is going to outperform my old weather warn penetrator, and most of the A99's around town.
:-)
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Tech291
Moderator
Username: Tech291
Post Number: 156
Registered: 11-2004
| | Posted on Thursday, April 28, 2005 - 6:51 pm: |
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Johncalifornia,
looks like part of your question got overlooked.The maco is known as dc grounded,which means there would be a direct current path from the radiator to ground provided it is properly installed.the wire from the so-239 does"see" a short to ground but the ring is in a sense a "loading coil" which makes the short invisible to rf energy.
tech291
CEF#291
kc8zpj |
Airplane1
Intermediate Member
Username: Airplane1
Post Number: 398
Registered: 5-2004
| | Posted on Thursday, April 28, 2005 - 7:19 pm: |
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Dennis, you always are a great help in understanding antennas. You realy know your stuff and I still did`nt forget all your great help you gave me on the Maco V. Mine would not be as good if I did`nt get all your help.
Thanks again,
AP
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Bigbob
Senior Member
Username: Bigbob
Post Number: 1844
Registered: 12-2001
| | Posted on Thursday, April 28, 2005 - 9:17 pm: |
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The ring is a tapped inductor. |
Road_warrior
Advanced Member
Username: Road_warrior
Post Number: 521
Registered: 7-2004
| | Posted on Thursday, April 28, 2005 - 11:37 pm: |
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Tech 291,
To be truthful i didn't know how to
answer that part of his question.
But, now i understand that part of it.
Thanks
JIM/ PA/ CEF 375 |
Johncalifornia
New member
Username: Johncalifornia
Post Number: 6
Registered: 9-2004
| | Posted on Saturday, April 30, 2005 - 5:12 am: |
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Thanks for your answer Tech291. I still don't know exactly how that part of the antenna works but I do know that it works well.
Today we put it up on a 10' poll, set the SWR's and compared it to a Golden CLR2 (looks like a regular CLR2 only has 4 legs instead of 3) from the same location and from the same 10' poll. From a station 30 miles away (barefoot) the Maco v-5000 hit the station with 1 s-unit more then the golden CLR2. I know that many people like the phrase "a 5/8 wave is a 5/8 wave..." but there is a difference or they would all perform exactly the same when tested. |
Al_lafon
Junior Member
Username: Al_lafon
Post Number: 12
Registered: 3-2005
| | Posted on Tuesday, May 03, 2005 - 9:50 pm: |
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I am planing on changing from tapped inductor ring to a gamma machining. O by the way take a
good long look at your manual this 5/8 is not a
true 5/8 tapped inductor at the base ! loading coil !! |
Bigbob
Senior Member
Username: Bigbob
Post Number: 1858
Registered: 12-2001
| | Posted on Wednesday, May 04, 2005 - 5:24 am: |
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Heck Al lafon if you have a metal roof where the edges are bonded and it's isolated from ground or not,you could use a gamma match and an antenna tuner to load it up and use it for an antenna.Interesting little experiment,ya think? |
Crackerjack
Intermediate Member
Username: Crackerjack
Post Number: 406
Registered: 7-2004
| | Posted on Wednesday, May 04, 2005 - 8:05 am: |
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A metal roof has about the same effect on a base antenna as a xartop does on a mobile -it can effect the directivity of a groundplane, by becoming part of the groundplane.
If I had a metal roof, I could shoot one heck of a signal toward our mission in Mexico -and don't think I haven't considered it, my house sits exactly pointed for just such an antenna.. LOL.. |
Bigbob
Senior Member
Username: Bigbob
Post Number: 1862
Registered: 12-2001
| | Posted on Wednesday, May 04, 2005 - 11:48 pm: |
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With an antenna tuner and a matching device you can load up just about anything metal to use as an antenna,some good some not so good,crackerjack imagine a tower in the middle of a used car lot.That roof does not have to be grounded but it will work better if it is electrically connected to the antenna tower or mast or metal base of antenna.Bigbob |
Crackerjack
Intermediate Member
Username: Crackerjack
Post Number: 413
Registered: 7-2004
| | Posted on Thursday, May 05, 2005 - 12:31 am: |
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Amen Bob! On the grounding, and it doesn't even have to be metal.
Fiberglass structures and as you have written someplace else, your trees and your house effects the radiation parrern as well.
I can tell the differenc when a local makes a 90 deg turn at about 10 miles and changes the directiviy of the antenna by turning the vehicle.
My Omni radiates better in a S-SW direction because of where I have the anrenna located -connected to the house.
There are just so many variables to consider. |
Twowatt
Junior Member
Username: Twowatt
Post Number: 17
Registered: 7-2005
| | Posted on Saturday, July 09, 2005 - 4:35 pm: |
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johncalifornia & airplane1,
think of the matching ring looking like a square "u" ..| |..... and at the bottom of the "u" the "resistance" is ........|_|.... at 0 ohms (and it is at dc and at rf freqs). next, imagine the top of the "u" is at infinity. now, somewhere closer to the bottom of the "u" is the 50 ohms point (at rf freqs. - it is still 0 ohms at dc).
this is the match point for your 50 ohm coax and where you will have 1:1 swr (and maximum xfer of pwr assuming the antenna is the correct length).
can you say 'j-pole'? 
hope this helps. regards.
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