| Author |
Message |
    
cobra
| | Posted on Tuesday, February 25, 2003 - 1:52 am: | 
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Hi,
I am going to put up this monster on a 70' tower soon. Most people in my town run a-99's and a strong station has a Maco 5/8. I have a Army Stick about 30" at the base. Anyway, what increase in s units should I see from the Stick to the beam? A local said I might gain 2 S units and it will be like I am running an amp but I am really barefoot to the people I usually talk with.
T H A N K S |
bruce
| | Posted on Tuesday, February 25, 2003 - 4:56 am: |
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4 elm = about 8 DBM or about 1.5 real s units NOW most meters are way off so if you see 2 units i would not be suprized. |
Number 5
| | Posted on Tuesday, February 25, 2003 - 5:39 pm: |
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If you have That Thing That High You will deffently beat the maco in a normal situation of talking Dx. But There is always a chance it can beat you If the condtions are right for the MAco. Just be careful Using it. When i had mine my local cb radio people were mad at me becuase i was bleeding on every channel if i was pointed there way. Maybe That DAvemade had something to do with It???
73's
Number 5 |
DeadlyEyes
| | Posted on Tuesday, February 25, 2003 - 6:33 pm: |
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Re The Point Of Diminishing Return....
For every antenna system or amp there is a point of diminishing return. A general definition of this is that point at which it becomes not worth the vast investment of $$$$ to achieve just a little bit of benefit. This is of course something you must decide for yourself. Where you draw the line is up to you of course.
BUT since you seem to be committed to putting up a nice tower how about a very nice antenna to go with it. And I am not talking a little four banger. I am thinking along the lines of a Super Lazer 500. No sir not the 400 but the full size kick heini 500 model. Heck big towers look very nice with big antennas. And that super lazer 5 will certainly give ya bang for your buck. If I remember correctly the calculated multiplication factor is over 50 to one.
Hmmm, I think our friends at Copper even sell the Lazer 500. |
bruce
| | Posted on Tuesday, February 25, 2003 - 7:18 pm: |
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cobra the antenna will make your 4 watts look like 30 into a a-99 and the best part it will increase recive the same amount. As for bleed over the beam will have no effect a beam unless its totaly coroded and detunes should not change your signal bandwith at all. |
cobra
| | Posted on Tuesday, February 25, 2003 - 8:51 pm: |
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I Live In a kind of richy neighborhood. When they see The antenna im putting and tower. They might run me out of the neighborhood. LOL |
de
| | Posted on Wednesday, February 26, 2003 - 6:58 pm: |
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Re cobra
Before you get too far into the antenna project you need to check to see if you have any restrictions on external antennas in your neighborhood. If there is a covenant tied to your property restricting/prohibiting external antennas and you put one up you are inviting a nice big legal action against you. |
Bigbob
| | Posted on Saturday, March 01, 2003 - 5:36 am: |
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GO with the lightning 8 lower profile,more gain,and much much lighter(copper wire vs aluminum tubes)instead of lazer 500. |
de
| | Posted on Saturday, March 01, 2003 - 10:44 am: |
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Re Bb....
Wire? Is it a quad type antenna? Just curious, could you list the stats on the antenna? |
Tech808
| | Posted on Saturday, March 01, 2003 - 12:30 pm: |
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de,
Yes, It is a 4 Element QUAD.
Boom: 15'2"
Elements Enamel Protected Copper Wire
Spreaders Rugged Fiberglass
Spreader Length 13' 7" Longest
Gain 14.6
Front to Back Ratio 38db
Wind Area 3.8 sq Ft.
Weight 20lbs
Power Handling Capability 8KW
Turning Radius 10' 1"
Hope this helps you some.
As soon as we get a little decent weather here in Central Illinois, I plan to have one up in a couple of weeks.
Subject to good help showing up! 
Lon
Tech808
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bullet 151
| | Posted on Saturday, March 01, 2003 - 1:35 pm: |
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ive run several quads and in my opinion after 5 elements youd be better off stacking beams than going longer on boom length. two four element quads will have better performance than the long 8 element beam.
this you can take to the bank! |
Tech833
| | Posted on Sunday, March 02, 2003 - 11:29 am: |
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But the longer beam would have a lower take-off angle than two 4-element quads side by side. Unless you stacked the 4-element quads one above the other with full-wave spacing (36 feet apart), you will not get lower than the takeoff angle of a single 8-element quad.
Lower take-off angle means longer transmit range. |
bruce
| | Posted on Sunday, March 02, 2003 - 9:31 pm: |
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lon 14,6 DBI? on a 1/2 wave boom with ground inhancement maby.... on 440 i got for 10 elems quad about 13 DBD measured still 11 dbd is nothing to sneeze at |
Bigbob
| | Posted on Sunday, March 02, 2003 - 10:19 pm: |
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Signal Engineering recommends 8 ground radials at least 36' long with 8 additional radials in between at 18' in length,these last 8 are optional,for lowest angle of radiation.They reccomended I do this to clear that 100' hill 8 miles to the north.They were trying to send me a program to calculate this when my cpu went down,just got on line again yesterday.My new comp.tower has 2.2gig celeron processor,256mb ddr sdram,60gb ultra dma hardrive,64mb ddr sdram graphics with 64mb shared video memory.Is this good,I'm not sure? |
de
| | Posted on Sunday, March 02, 2003 - 10:26 pm: |
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Re 808...
Not bad that would put the effective multiplied to be about x32. And a theoretical S Unit gain of a little over 3 S units. Not too bad
DE |
Sixkiller505
| | Posted on Tuesday, March 04, 2003 - 7:09 pm: |
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tech 883- have you seen the lighting 4 plus?? boom 17ft-gain i5.1-fb 40db-side44db----- and they are made by the same company 505 love country |
Tech833
| | Posted on Wednesday, March 05, 2003 - 11:54 am: |
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Not only have I seen them, I assembled and installed one for my dad several years ago.
It performed better than he expected. He was very happy with it. According to him, he was now a 'big strapper'. I am learning the CB lingo a little at a time. |
Bigbob
| | Posted on Monday, March 10, 2003 - 12:25 am: |
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HEY YOU GUYS,signal engineering recommended 8 36 foot ground radials attached to the base of my mast for my white lightning,I don't have enough room,bruce said I could use folded radials,but I forgot to ask him what the spacing between the legs should be,you guys got any ideas? |
Marconi
| | Posted on Monday, March 10, 2003 - 5:49 am: |
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Hey Bigbob, it would be nice to have them all fanned out in a perfect circle and all cross tied together every 4' out in a circle or so, but if you have to bend them to fit the perimeter and/or the landscape and forget the cross-tying, then do it. If you have the room a couple of 72'ers or longer wouldn't hurt either. Don't forget a couple or three 8' ground rods placed around and attached a foot or three away. |
bruce
| | Posted on Monday, March 10, 2003 - 7:39 am: |
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BOB WHY????? is this for " GROUND INHANSMENT" if so to work you would have to have the antenna CLEAR of everything for at least that far and it dosnt sound like you have all that much space. Ive tried this trick in the past and to be honest it did little for me. |
Tech833
| | Posted on Monday, March 10, 2003 - 12:45 pm: |
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Marconi,
You don't need to bond the ground wires except at the center point. It makes no difference at all to bond the ends or middles of the ground system.
Bruce, you must have had very poor ground conductivity. Adding a ground wire counterpoise beneath an antenna on 27 MHz. should decrease the takeoff angle considerably.
The more wires (greater than 1/4 wavelength) the better. Ask the engineer of your local AM broadcast station what the ground system looks like. Duplicate that! |
bruce
| | Posted on Monday, March 10, 2003 - 1:40 pm: |
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The ground here is sand just sand and at 50 mhz i tried 8 wires at the base of a 45 foot tower holding a 4 elm beam they made no diffrence at all so much for " ground enhancement"..... well at least they gave a good ground for lighting. |
Bigbob
| | Posted on Monday, March 10, 2003 - 8:39 pm: |
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S.E. recommended 8 36'radials and 8 18' radials tied at center to bottom of mast,this was in reference to 100' hill straight north 8 miles,actually a ridge 10 miles wide,between me and in-laws station 90 miles north in u.p. of micigan.10 miles north of that ridge is 44 miles of lake michigan.Their tech said it would bring down take off angle such that it may increase signal strength as much as 3db at lake level,he tried to send me program software by e-mail but could not said he would get it to me one way or another.Said to be absolutely sure I would have to take remote measurments myself several different days to rule out weather conditions,sounds like fun digging in the grass,wheeee,lawn.By the way sandy soil with water everywhere 7' down winter,spring,summer,fall,soil is moist to touch at 2" depth even now at -2 ferenheit HAVE I GOT GROUND CONDUCTIVITY OR WHAT? |
bruce
| | Posted on Tuesday, March 11, 2003 - 4:37 am: |
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They are talking ground enhancement which 833 also said works but i have had little luck with it. Now if your beam is up under 36 foot it could be a efective way to gain some .... it always looks good .... on paper. |
Bigbob
| | Posted on Tuesday, March 11, 2003 - 8:18 pm: |
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I would imagine the denser the electromagnetic field the greater the effect,thus 36 feet would seem to be the upper limit for 4 watts @ 27mHz. |
bruce
| | Posted on Tuesday, March 11, 2003 - 9:47 pm: |
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once you get 1 wave away from the ground any effect starts to go away and the take off angle should be almost at minumn. Its a neet effect but ive never got it to work for me although at low frequencys like 17 meters with enough space i would like to try this ! |
Tech833
| | Posted on Tuesday, March 11, 2003 - 11:51 pm: |
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More than a full wave can make a difference. In ground systems, wavelength is not as important as gaining ground conductivity. Think of an antenna as a transducer. It's job is to induce a current half into the air and half into the earth. The ground system is required to complete the capacitor and induce current into the earth. The diameter of the disc does make a difference in the capacitive value in a ceramic disc type capacitor, right? Same thing, although to a lesser extent in this case. |
bruce
| | Posted on Wednesday, March 12, 2003 - 12:36 am: |
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833 im well aware of what you are saying and its correct however om 6 and up i have never been able to show it works ..... i guess its this SANDPILE! |
Tech833
| | Posted on Wednesday, March 12, 2003 - 9:45 am: |
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Well, starting around 6 meters and heading up, it will have little to no effect, Bruce. Sorry about that!
The good news is, starting around 6 meters, the antenna elements themselves get small enough that stacking elements for high gain becomes practical. Maxrad makes dipoles designed for stacking for 6 meters and up. You can buy 4 dipoles and coax harness and mount them on a tower or tall pole and get 9 dB of REAL gain in an omni antenna.
If you wanted to do that on 11 meters, it would require at least a 160 foot support structure. Not very practical, especially since the part 95 rules state that a CB antenna can't be more than 60 foot AGL or 20 foot above the roof of the building it is on, etc. |
bruce
| | Posted on Wednesday, March 12, 2003 - 11:30 am: |
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833 you mean cb has RULES?..... if i get the chance to put up a 17 meter antenna other that the G5RV it would be interesting to see just how muh effect all of this would have at 18.1 mhz Back in the early 70's i ran 4 stacked 6 meter squalos a very neet antenna for ssb i still have one of the squalos and im going to put it back up maby on the same pole that the copper skylab is going.... stay tunned! |
Bigbob
| | Posted on Wednesday, March 12, 2003 - 10:18 pm: |
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But,the question still is,what is the spacing between the legs of the folded radials.Can they be in the shape of a J or a U or an L,say with equal length legs.My mast is up against the east end of my house,no problem crawl space,got 75' to the east,14' to the south,18' to the north,you see my problem?Oh by the way what if I tied the 80'steel frame of my mobile home to the mast? |
bruce
| | Posted on Wednesday, March 12, 2003 - 10:34 pm: |
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Theres a idea use the frame? i think as 833 said just lay out as many as you can and he says you will see a improvement by your own dimentions you have enough room for several of them the rest i would just S shape them if need bee |
Tech833
| | Posted on Wednesday, March 12, 2003 - 11:54 pm: |
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The ground radials are most effective if they are not bent, but straight. You are better off having short radials in some directions than bent ones. |
bruce
| | Posted on Thursday, March 13, 2003 - 12:37 pm: |
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833 have you ever experimemted with a decoulping skirt of radials mounted 1/4 wave down from the ground plane??? |
Bigbob
| | Posted on Thursday, March 13, 2003 - 7:08 pm: |
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Maybe I can sneak around the fence on both sides at night and bury the wires,I know this is getting strained but what gauge do you recommend,18 enameled or 12 house wire. |
Tech833
| | Posted on Friday, March 14, 2003 - 11:03 am: |
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Bruce, Yes.
Bigbob, Do not use enameled wire. You must use bare copper wire. I suggest nothing smaller than #10. For AM broadcast stations you usually see #10 or #8. I rarely see #12 anymore, but there are a few out there. #12 does not last long and tends to be damaged easier. Rather than wait until night and jump the fence and trespass, why not contact the neighboring land owner and ask permission? |
Bigbob
| | Posted on Saturday, March 15, 2003 - 5:47 am: |
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Yeah,good idea. |
bruce
| | Posted on Saturday, March 15, 2003 - 10:14 pm: |
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833 how did it work for you? i was thinking of doing that to the skylab? |
Tech833
| | Posted on Sunday, March 16, 2003 - 11:55 am: |
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It won't make any difference you will be able to see on 6 meters. It made a lot of difference on some SW stations in the 15 MHz. band since we couldn't get the half wave dipole towers up any higher. |
Tech833
| | Posted on Sunday, March 16, 2003 - 11:55 am: |
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It won't make any difference you will be able to see on 6 meters. It made a lot of difference on some SW stations in the 15 MHz. band since we couldn't get the half wave dipole towers up any higher. |
Tech833
| | Posted on Sunday, March 16, 2003 - 9:01 pm: |
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I must have been using my echo keyboard to type that message. |
bruce
| | Posted on Sunday, March 16, 2003 - 10:33 pm: |
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Thats OK
Thats OK
833 MOST of my 40+ years in radio has been spent on 6 and up for years i worked in R&D MMwave ( 96 GHZ)and on 800 and 400 meg public safety systems As for ham radio 6 is my band and realy enjoyed 6 meters its nice to be getting back on there .... since 1966 i have 35 states worked and im a rag chewer not a dx hound. I still have to had the " ground enhancement" effect work for me..... hummm 17 meters i wonder....The SKYLAB is built ill get it up this week and send a photo of COPPER'S newest 6 meter antenna! |
Bigbob
| | Posted on Monday, March 17, 2003 - 6:39 pm: |
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Why not a ground-plane 1/4 wave below the base of the antenna at maybe 90 degrees or 120 degrees,I've seen some old folded ground planes with the extra radials that were used at 47mHz,why not 50mHz? |
