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03
| | Posted on Thursday, July 11, 2002 - 11:04 pm: | 
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Hello - Because of my location I cannot use guy wires. I want a new antenna and can mount a Maco at 30' at the base or a Imax at 40' at the base. I know the Maco is a better antenna but would my signal be stronger using the Imax 10'higher? Does 10' higher matter? I live in New Orleans so I do not have any hills...
THANKS
Operator 03 |
Funtimebob
| | Posted on Friday, July 12, 2002 - 12:01 am: |
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Uncle Charlie dictates a maximum height from ground to top of antenna of 60 feet unless its been changed and I'm unaware...... |
Dx431
| | Posted on Friday, July 12, 2002 - 1:54 am: |
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Both ants. are 5/8, the Imax is lihgter in wieght than the Maco.And yes, 10' does make a differance.
Funtimebob, the way I understand it, is, 60' to the base from the top of a man made object,now, if is 60' from ground to top of ant, then there are alot of illegal ants. |
bruce
| | Posted on Friday, July 12, 2002 - 10:22 am: |
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unless it has been changed its 60 foot above ground and some countys have building codes like here if it is more than 35 foot you have to have a permit i would check with your local goverment to see if they have a set rule and in this case PRB-1 does not apply.
Here is the rule from the fcc web site
There are no height restrictions for antennas mounted on vehicles or for hand-held units (CB Rule 8). For structures, the highest point of your antenna must not be more than 20 feet above the highest point of the building or tree on which it is mounted, or 60 feet above the ground. There are lower height limits if your antenna structure is located within two miles of an airport. |
jyd
| | Posted on Friday, July 12, 2002 - 10:24 am: |
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the best is 36 feet the first wave length.you will get the best conditions at this highth.dx431,what do you mean illegal antennas.diffrent towns have diffrent requirments.for instance poplar bluff,missouri you can be up to 100 feet past that you have to put a blinking light on top. |
Dx431
| | Posted on Friday, July 12, 2002 - 10:53 am: |
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jyd, you're right, i forgot about the blinking light.
Bruce is right about the airport. I live 2 miles from the Scribner Air Base. My beams are at 40 + ft., but I live in a hole. I have a 60' hill 50' from back door. If I was to put my tower and beams on that hill, I would need a blinking lite on it. |
bruce
| | Posted on Friday, July 12, 2002 - 11:06 am: |
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jyd a cb antenna is restricted to 60 foot what your talking about is comercal or ham antennas and the blinking light is a FAA rule |
Tech833
| | Posted on Friday, July 12, 2002 - 1:25 pm: |
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03,
If you cannot mount your antenna very high above ground level or obstructions but still want a lot of signal, I suggest either a quad type beam or for an omnidirectional antenna, the CTE copy of the Astroplane Radiator.
Neither of these antennas mentioned will lose efficiency as they are mounted closer to the ground. Obviously, getting your antenna as high as possible is the best method, but if that is not possible, then you must choose an antenna which is not affected by close proximity to ground if you still want to 'get out'.
As another idea, the Imax 2000 with the ground plane kit could be used with satisfactory results. |
Marconi
| | Posted on Friday, July 12, 2002 - 8:27 pm: |
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I don't believe 03 is even interested in the rules here. He just wanted to know what he might expect if he did either installation. Knock, knock, wake up guys.
Personally, I don't think he will notice any difference assuming the antennas are working well. You may see a little difference in signal with the higher position, but it won't make any difference as to whether you make a contact or not.
Here is the kicker 03. I don't think you will want either one up there at 40' if you are going to use a pushup pole and not guy it. Even at 30 feet it can take your restful sleep away wondering if it will be in a neighbors stuff one day during a little thunder or wind storm.
Simple! If you have a good, well installed, free-standing tower, then go for it, as high as you can get it.
If you think the Maco is better, then don't even consider the other. You will always be second guessing your decision. Both are good antennas and the Maco could present problems with tuning, but if it is even close to right then it will work fine.
Marconi |
Bigbob
| | Posted on Friday, July 12, 2002 - 11:08 pm: |
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Or 18' above the supporting structure like a 60 story apartment building,now that's gain.hooboy!!!! |
03
| | Posted on Friday, July 12, 2002 - 11:48 pm: |
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Thanks for the info. I am going to mount it on the roof eve peak that is at 20'. I am going to use a 10' pole for the maco and maybe a 20' if I would get the Imax. I know I can go higher with the Imax because it is much lighter and won't fall in the wind. I think I will go with the maco...
THANKS GUYS
03 |
Hoosier Cardinal
| | Posted on Saturday, July 13, 2002 - 10:01 pm: |
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Maybe we should rename the forums from Copper Electronics Forum to the FCC rules and regulations forum...... |
bruce
| | Posted on Sunday, July 14, 2002 - 7:23 am: |
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Hoosier..... Antenna regulation is much more a local issue. Here in pinellas county our building dept allows 35 foot to the top of a antenna then you must have a building permit. The city of st.pete code inspectors have hit a number of cb'ers and a few hams THEY require a engineer draw up the plan for your antenna and it must be good for 125 mph. Now this IS being contested since the FCC has a rule called PRB-1 but PRB-1 realy does not cover building codes and the ARRL is tring to get laws passed to restrict citys from doing this so like i said it an't the fcc beware of your local goverment if they think they can make a buck
bruce |
Taz
| | Posted on Sunday, July 14, 2002 - 8:13 pm: |
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i would have taken the imax. |
Highlander
| | Posted on Sunday, July 14, 2002 - 11:16 pm: |
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Tech 833, I can't find any retailers in North America that have the CTE Top One----do you know of any? |
Tech833
| | Posted on Sunday, July 14, 2002 - 11:40 pm: |
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I bought one about 6 months ago at the local CB shop. I'll ask where he got it from. Also, you may give Copper a try. I would just about bet my favorite toolbox that Suzanne may be able to special order one for you.
The center fed 'Top One' (Astroplane copy) will work extremely well at lower elevations where end fed 1/2 wave antennas will not. An end fed antenna's takeoff angle rises dramatically as you mount it closer to the ground. A top or center fed antenna is not affected in the same way since the voltage node, not the amperage node, is near the ground. |
Galileo
| | Posted on Monday, July 15, 2002 - 12:53 am: |
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Dont worry about multiples of wavelength with these antenna designs....The higher the better..!0 Foot will make a difference in local range.. |
Tech833
| | Posted on Thursday, August 01, 2002 - 11:00 am: |
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Galileo, Unfortunately, that is untrue. 'Local' range is affected just as much as DX is by an antenna's takeoff angle.
Even at 1 mile, a 10 degree difference in takeoff angle can mean 3 dB or more signal. Lowering your antenna's takeoff angle is the single most important thing to achieve in order to increase the range of a lowband station. a 1/4 wave ground plane antenna mounted 50 feet above ground will cover much more earth than a 5/8 wave antenna at only 10 feet above ground. This information is widely available and is covered in-depth by the ARRL antenna book. |
Taz
| | Posted on Thursday, August 01, 2002 - 8:35 pm: |
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I would have put the imax at 40 feet! |
Marconi
| | Posted on Friday, August 02, 2002 - 9:30 pm: |
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Hey 833, I think Galileo was likely referring to JYD's post about his considerations given to setting a ground plane antenna at a particular wavelength height. JYD notes that 36 feet was a significant factor bringing about the better communications. I took Galileo's statement to, more or less, argue that it probably did not make that much difference with a good ground plane antenna. To me, it sounds like he is implying the same thing you noted in your example of the 1/4 wave vs. the 5/8 wave at different heights.
BTW, I am posting a question to you in the discussion area on your report about the Imax 2000 GPK.
Marconi |
Galileo
| | Posted on Saturday, August 03, 2002 - 3:27 pm: |
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Hey tech, I agree with you on that..That was not the point of my post..I did not make myself clear..What I meant was with a groundplane "Type" antenna, wavelength height is not much of a consideration..40 foot would be better than 33 foot..On dipoles, and exotic antenna systems it is an important consideration..So for most of us higher is better as you do cover more earth..Im not real good at putting all this down in writing...Tom Shaw |
dale
| | Posted on Thursday, August 29, 2002 - 4:51 pm: |
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taz i would have gotten the imax2k also |
Disco Duck
| | Posted on Thursday, August 29, 2002 - 9:43 pm: |
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The Imax might be easy to put up but the Maco is a real antenna and it will walk the dog on any Imax anytime.. |
bruce
| | Posted on Friday, August 30, 2002 - 7:40 am: |
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above 1 wave (36 foot) it realy should not matter as for which is best well my take is a 1/2 wave no mater who makes it is a 1/2 wave and if tuned corectly should all work about the same....My mosley 5/8 wave at 2 waves above the ground has worked for 28 years and is just now needing to be taken down. |
the hobo
| | Posted on Friday, August 30, 2002 - 1:48 pm: |
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say hey, the hobo here.. on the imax and maco 5/8
had both up at 72 feet to the bottom of the antenna at the same time, at 50 foot apart.. the
imax is still up, and the freind that bought my maco, has just sold it and bought him a imax????
just me and my nickle.
the hobo
2tx1000
274150 am |
Taz
| | Posted on Friday, August 30, 2002 - 4:44 pm: |
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Well, Im sticking with my Imax. Theres somone out here with a maco and hes a mud duck. Gets stepped on from the truckers even. |
bruce
| | Posted on Friday, August 30, 2002 - 6:04 pm: |
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Taz
id rather a Decebel products Super station master.... 9 DBD gain.... too bad they dont make them for that low a frequency... so i use mosley 3dbd instead. Basic rule is if its the same size its got the same gain.... somehow its always works out that way. |
Tech833
| | Posted on Saturday, August 31, 2002 - 11:23 am: |
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Bruce,
Don't forget about the efficiency of the feed system, the Q of the matching circuit, and the materials the antenna is made of. Those can all contribute to the 'gain' of the antenna as well, maybe even giving a shorter antenna more 'gain' than a longer one.
Taz, what kind of coax is your 'mud duck' using with his Maco V-5/8? There are other contributing factors such as ground conductivity, ground system, power output, cable length and loss, nearby reflection sources, multipath, etc that you may not be considering. There's a lot more to RF coverage than just choosing a long antenna or your 'favorite' antenna.
I can't stress how important the antenna SYSTEM is to overall performance. Your radio's RF output sees everything from the coax connector on the back of the radio onwards as a whole system. Your library should still have a copy of the ARRL antenna book. If not, Fry's Electronics or AES sells it. Check it out. |
Taz
| | Posted on Saturday, August 31, 2002 - 1:18 pm: |
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Tech 833
Hes using rg-213u
Height is 55 feet to the bottom and has flat swr.
He is 6 miles from me.
He runs 2 8 foot ground rods. All his radios amps and meters are grounded. (properly)
He runs a texas star 350 from his house.
There is no reflections in his area.
I think about things before I post, of course I do make errors but who doesnt.
He just doesnt get out, I told his it worked better when he had his antron99 up.
Taz |
bruce
| | Posted on Saturday, August 31, 2002 - 6:47 pm: |
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For years ive heard this " high Q, matching, low loss materals and overall lengh.It is TRUE is incorect things are used or badly done like the famous cushcraft coliner DX arras for vhf/uhf which used polypropoline insulators things can and will go wrong. For WR4ANA we tested 4 antennas hygain, cushcraft, AS and mosley all except the cushcraft were 5/8 wave. the cushcraft " ringo " was far below the the others in fact no better than the 1/4 wave ground plane which was our referance. The mosley was chosen because it had a external matching stub and was easy to tune and after 28 years it is now getting to the point that the COAX is bad so its comming down and im going to take a shot at rebuilding it.
On 52.5 meg haveing built or bought a number of verticals LENGH is the one constant as far as gain I even had a RINGO RANGER 6 DBI gain a 5/8 STACKED over a 5/8 wave for 6 meters 25 foot tall!! on cb it would be 50 FOOT tall.... gosh it worked good BUT could not stand the high winds we get in our summer rains and bent after less than a year. Most name brands do a good job of building the product even cushcraft has come a long way since 74.
Bruce |
Bigbob
| | Posted on Sunday, September 01, 2002 - 12:30 am: |
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How long is his coax,and how old is it from actual date of manufacture,my dad-in-law has some 8-au foam coax,belden,it's at least 30 years old looks as good as it did new.But with a 4watt input to a 50foot section it has a 75% loss and if we use it into a high swr things look good at the radio end,but little or nothing is getting out the antenna. |
Taz
| | Posted on Sunday, September 01, 2002 - 2:10 am: |
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He has 86 feet of it. Manufactured 8/12/01. |
Bigbob
| | Posted on Sunday, September 01, 2002 - 7:42 am: |
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Are the connectors secure?rg-213 is a real p***er to do with out melting the dielectric or getting a cold solder joint or a mechanical connection with flux in the joint.My uncle just folded back the shield and screwed on the connector and soldered the center conductor,we had to take it all down and do it right a year later,haste makes waste.There has to be a reason for his stations lack of performance,if you can discover it,you will have learned something,something as simple as a loose adaptor or so-239 connector center can mean as much as 3to1 swr,if it's before the swr meter how will you know,by manual check.I know you're not stupid,you've probably already checked these,but if not go for it.Because stations just don't get out for no reason there has to be a simple logical explaination. |
bruce
| | Posted on Sunday, September 01, 2002 - 8:26 am: |
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bigbob 2 things i never buy old carbon comp resistors and old coax nither will work |
Taz
| | Posted on Sunday, September 01, 2002 - 2:09 pm: |
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Bigbob,
I have gone to that house with several of my radio friends and we have looked at every little part of that station in and out and through every nook and craney.
We have even had antenna anaylizers over there.
THE ANTRON GOT OUT BETTER! We replaced all the ends!!!! Checked swr at the radio and at the antenna! FLAT!
Tried different radios
Different Mics!
We even put his antron back up and it worked better!!!!!!!!!
Im telling you now that the simple explination that his station dosent get out is his maco. |
Tech833
| | Posted on Sunday, September 01, 2002 - 7:35 pm: |
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Taz,
You mentioned that there are 2 ground rods grounding this system. If the rods were 8 foot each and they were closer than 16 feet to each other, they would cancel each other out. You cannot place ground rods closer to each other than their combined length.
Although the SWR is low, what is the bandwidth? Perhaps the antenna is tuned to some notch resonant spot? It should be better than under 2:1 over 1 MHz.
As for everything else, I'm at a loss. |
Bigbob
| | Posted on Sunday, September 01, 2002 - 8:34 pm: |
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oky doky,I'm not there,you think you could put a pic of his station on this forum?that is the antenna and surrounding area? |
Bigbob
| | Posted on Sunday, September 01, 2002 - 8:47 pm: |
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HEY I just thot of sumthing using a tuner I can get 2 diff. spots flat swr on any frec. you set the tune and load caps at 2 diff spots and the inductor also put a watt meter on end of coax with dummy load,you can tune flat swr with max watts or min,watts with trans. set at max watts the min watts setting(tuner) seems to be tuned into a null and this would react diff with diff antennas,what do ya think bruce am I all wet? |
Taz
| | Posted on Sunday, September 01, 2002 - 11:25 pm: |
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If I get a chance to run over there and take a picture.
There is nothing around his antenna at all for about 70 feet but its highest point is at about 30 feet. |
Magnum410
| | Posted on Sunday, September 01, 2002 - 11:58 pm: |
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I hope this helps the Imax/Maco debate a little.
About a year ago I swithed from a Maco 5/8 to a Imax2000 and I didnt notice any recieve gain or loss, but everybody told me I was alot louder and gave them a little better signal. I didnt change anything but the antenna. The Maco always gave me trouble in weather. SWR problems when it would snow or ice up. |
Taz
| | Posted on Monday, September 02, 2002 - 1:21 am: |
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My point was that the highest point of that object which is 70 feet away is a tree with a highest point of 30 feet. |
Taz
| | Posted on Monday, September 02, 2002 - 1:21 am: |
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IMAX 2000 all the way. |
Tech833
| | Posted on Monday, September 02, 2002 - 11:04 am: |
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The Imax 2000 is indeed a good antenna. A good design with good quality internal components. The only drawback to the Imax is the fiberglass being too weak for the task. I have nothing at all against the Imax, I'm just trying to figure out why Taz' friend is having such disappointing results with his Maco. They should perform about the same.
There should be no performance advantage to the Imax over the Maco or vise-versa. An aluminum antenna like the Maco would be a better choice for windy conditions. Of course, Jay in the Mojave's I-10K is a lot stronger than the Maco by far, and is a must for those who ever experience 70 MPH+ winds. The Imax 2000 I have has been laying over on its side in winds of about 45 MPH and looked like it was about to snap. I already see stress cracks and splitting in the fiberglass after only a few months in the air. It won't last much longer. I have decided to take the Imax 2000 down before it hurts somebody (it is 85 feet at the mounting bracket on a tower above a large parking lot).
I plan to re-fiberglass the two bottom sections using glass cloth and West System epoxy products. I'll report what happens. |
bruce
| | Posted on Monday, September 02, 2002 - 12:32 pm: |
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You can fight it out imax, a99, jay in the middle of no where.... duleing pistols at 20 pases gosh im glad no one brought in a ringo ( yuck) If i cant get a DB produts Ill stick to my MOSLEY (LOL) |
bruce
| | Posted on Monday, September 02, 2002 - 3:28 pm: |
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bigbob my MFJ 945 does strange things too if i tune up on 17 meters i can switch to 50.125 on 6 meters and crazy as it sounds the antenna is close enough that without retunning itas under 2/1 so i dont worry heck its just one less thing i have to do when i switch bands antennas and tunners are so much fun O'buy the way some one made the statment antenna tunners are junk no they are not they " TRICK" the radio into thinking its looking at a good match and in my case it lets me work from 160 meters to 6 meters on a 34 foot long antenna!
Bruce |
Alsworld
| | Posted on Monday, September 02, 2002 - 10:35 pm: |
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okay Bruce,
I gotta ask about the newer cushcraft ringo 2 antenna's. I'm looking at the ARX2B base for 2 meters. Are these antenna's junk as well or do you refer to older versions?
Alsworld |
bruce
| | Posted on Tuesday, September 03, 2002 - 7:04 am: |
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the ringo ranger is a fine antenna the old 10/11 and 6 meter ringos are junk the ringo rangers are the standard for 2 meter fm thousands of them out there i have one its at least 15 years old and still working fine. |
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