Assembling Your Antenna System

8/10/2019 Assembling Your Antenna System

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Assembling your antenna system

One step farther up (I)

After your transceiver, the antenna system isthe next most important part of your haminstallation if not the first one. Without antennayou are condemned to look at the sky instead oftaking advantage of its sky waves, Hi !

For the beginner it is not always easy to knowwhat antenna, what tower, what siing or whatrotator to select. f you decide to install a towerand a respectable antenna, here is a good advice."isit other amateurs who erected aerials ontowers or masts, see how their hardware isinstalled, ask them #uestions about the ease ofhandling, if they worked alone, what problemsthey encountered, how they solved them, how allthat is grounded, how long last the assembling,where they purchased their material, at whatprice, etc, to see if you might handle such apro$ect, and if such an installation can be erectedin your garden or on your roof.

%&'( ) W*+ attaching their -element/+m antenna. 0ocument1ustom

2etalworks

f this task is not too difficult to handle for a simple "34HF antenna, for the HF bands thescale of the elements to take in consideration has already did move back some amateurs, and personally wait about two years before installing my tower. ndeed, if the choice of a rotatingsystem is not a problem, the sie of the tower might be one for different reasons 5price, furtivity,authoriation, handling, security, etc6, so it will #uickly become your biggest problem to solve !

We must thus divide this problem in two parts 7 first, discussing the re#uirements to work on

"34HF, then the re#uirements to operate on HF what will automatically lead us to answer tosome #uestions such as what rotator to select, what tower design is the most resistant 8, howto assembly it 8, how to place the antenna on top 8 or how to maintain a tower and itselements 8

9housands radio amateurs around the worldsuccessfully installed their antenna on top of atower, so can already ensure you that this taskis in the capability of any amateur, at thecondition to work safely, with appropriated toolsand knowhow, as much issues that we aregoing to review below.

:o, make one step forward and soon fartherup ! We will successively review the following

sub$ects 7 How to selection a tower 1onstructing the tower base Assembling the tower 9he anchorage system nstalling the antenna system

%-4;< #uad. =nlarge to see an overall view.

f you haven


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Practical limitations of your installation0epending on the country in which you live, any construction made of concrete 5e.g. your

foundations even if they are invisible and will never exceed the ground level6 or an aerialerected farther than >+m away from the street 5e.g. at the far end of your garden6 or at a heightexceeding about ?+ m 5@@element homemade #uad displayedabove 5for -+3?m6, all these buildings are sub$ect to the approbation or refusal of the localordinances 51adastre, 9own ) 1ountry 'lanning Acts, 2unicipality administration, etc6. ;obefore embarking you in any ma$or aerial installation, it is advisable to contact your localordinances and if necessary to apply for planning permission. f it is accepted the permit isusually delivered in a few weeks or after a few months if your building exceed standards 5e.g.erected over >+m away for the street, higher than ?m up, etc6.

;ome municipalities will be very restrictive about this sub$ect while others will let youpractically erect what you want while respecting your neighbouring.

Bf course many amateurs do not ask for this approbation from the moment that theirbackyard or their roof is large enough to erect a beam without disturbing their neighbouring.ut this is at your risks if one day a municipality agent knocks at your door re#uesting yourplanning permission or showing you a legal restriction for the height of your tower or thewingspan of your antenna.

;everal factors are to be considered before installing a tower 7

9he sie and weight of the antenna desired 9he weather conditions 5speed and fre#uency of wind gusts, risks of thunder, snow, ice,

tornado, cyclone, etc6 Cisk of earth#uake and underground stability 9he ease of assembling of the concerned tower Any legal restrictions with local ordinances 5about building, height, distances, etc6 Free space available in garden or on roof 5to prevent that the antenna falls onto the

neighbor


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The light and stealth antennas (II)

efore to begin, say a few words about the light and stealth installations that are used bymany amateurs living in cities or in areas sub$ects to strict regulations. f you live in anantennarestricted neighborhood, you will have to make a compromise between theperformance and the sie of your antenna system.

Bften you will have to fall back onshortened beams, wire beams or evenverticals. ut even in this case a mast?+m high made of thick aluminiumtubing doesn


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For a permanent installation, your mast must resist tothe forces generated by the weight of the antenna and thestrength of the wind. ;o you must select a very sturdymast or a tubular tower made of heavy duty aluminium5light, not too expensive6, steel 5stronger but heavier6 ortitanium 5light, robust, but more expensive6 able to sustaina force over ?++ kg hours long.

We do not improvie the assembling of a permanentantenna. %now that by tempesty wind, gusts can reach?+ km3h 5??+ mph6, the wind exceeding often + km3h5+ mph6 on top of hills. n open fields, your mast or yourtower will #uite regularly be sub$ect to wind gusts inexcess of ??+ km3h 5&+ mph6 too. f you desire to install alight mast in windy areas, can already confirm you that agalvanied steel mast @ mm thick 5?3I wall6 or a chromemoly mast mm thick 53?>I wall6, both telescopic and +mm 5-I6 in diameter, cannot support such stresses and willbend 5say -+J off vertical6 or can even break under windsof ??+ km3h. A towerwork, even IlightI, must replace so

light installations.

An Hexbeam5a @kg wirebeam6.

9o resist to high winds, the other solution should be to lower the mast up to -m high or to tiltit until the ;un shines again. 9his is also valid for towers.

f you cannot invest in such an installation, you can already resolve partly the problem ininstalling the antenna in a lift system, also very practice to service the antenna. Cemain tosecure the tower, but what tower to select 8

Selecting your tower9he selection of a tower is a serious affair that should respect the professional standards

and offer the highest security. 9owers come with a triangular or s#uare base from @+ cm to ?mwide 5?+/+I6. A ?+ m high 5@@


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At left, :@:


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rand new towers are not more expensive than other ham products. ut made of a IsimpleItubular structure, they worth well their price, all the more that their stability can never beensured at ?++L. 9o fix your ideas their price is ranging from M/++ for a @m high 5Nm high 5=93F'(,A( Wirelessand 19A.

9he secondhand market can also provide you reliable models at one third of that price if notless. Bnly one precaution, if you buy a secondhand tower, check the inside of tubings whererust could accumulate or where small cracks could appear. t shouldn


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the towerssold byCohn ndustries, 4; 9oweror 0e %erfare probably among the mostappreciated by the ham community.

ut not be disappointed if you don


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onstructing of the tower base (III)

First, do you respect the regulation 8 Forsecurity reasons, like any ob$ect erected inheight near housings, to avoid that thetower falls on someone or on the housingsby high winds, even if it is bolten in a deepconcrete base 5its top can break6, you mustlegally secure your tower in placing it at adistance of at least ?. times its height fromany infrastructure n taking a ?+m hightower, the legal distance is ?m fromhousings and -m away from theneighbour+ ft6.

Assembling a tower re#uests skills and a serious planning. f this is your first construction,that it is to support a -element #uad or a bigger gun, it should be interesting that you visitsome near building sites to see how they start work on the concrete base or how they constructa big pillar for example. Cead also the ham magaines that regularly publish the works of thebest handymen as well as books devoted to antennas published by ACCE or C;: forexample that usually reserve several pages to masts and supports 5ACCE Handbook, C;:

Antenna File, etc6. Dou could also find these publications in large libraries.f you purchase a new tower, the manufacturer will provide you detailed instructions for

properly constructing the base and assembling the tower. f you have no plan, you can alwaysIcopyI the instructions of any other tower or the ones found in magaines, and if necessaryslightly modify the dimensions to your needs, what most amateurs probably do.

The foundationsAny builder used to work with concrete and steel should tell you that a tower should be

erected over a concrete base reinforced with a steelbar framework on which the feet or thetower base assembly will be boltened. 9his is the classic way of installing a tower safely. 9heconcrete base is driven in a hole from +.?.m depth 5-+>+I6, depending the weight, thelength and the design of your tower. 9his hole is -+L larger than your tower in order to insertwithout problem the steel framework $ust in the middle of the space. 9he hole must be large

enough so that the anchorage system can be partly sunk in the concrete. 'lace at the bottomof the hole a few big rocks to support the framework. 9o keep the li#uid concrete in position, awood form made of fir wood boards cm thick 5-I6 is constructed around the top of the hole. fthe soil is poroux, crumbly like sand or too soft, the concrete might flows into the ground. n thiscase densify your concrete and drive a hole twice as large.
http://www.astrosurf.com/luxorion/Radio/tower-base-hd60-ad8c.jpg


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'lans for installing a concrete base able to support a tower up to /+ m 5?/+ C=bar as long as your hole but shorter, thatwill be placed vertically near the corners of the hole. All ends should be bent to the inside. 9his

frame is consolidated and bond to horiontal loops made of (o./ C=bars wired to the verticalrungs each + cm 5-+I6. ;o you need only @ steel hoops on all the lenght of the framework.

After building check all dimensions and that all segments are well perpendicular to eachanother. t is not mandatory to level the steel framework as it will be sunk in concrete but try toprevent any potential problem.

Although we will review this issue when we I6, sunk at approximatively @3/th of their length in the concrete. 9hey muststand out of the concrete to bolt the base assembly. 9he optional thread will be adapted to yournuts. ut do not work for nothing as, as we $ust told, the anchorage system, bolds and nuts areusually provided by the tower manufacturer.

When all tubular elements are welded and assembled, insert the steel framework in thehole, well vertically, and $ust after put the anchorage system in the middle. ind it to the C=bar


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to create a ground system, called in this case an 4fer ground. 1heck immediately that all isproperly set with the level and the ruler. n case of mistake do immediately the ad$ustment.

The concrete baseFrom the proper installation of the anchorage system will depend the sturdiness and plumb

5verticallity6 of your tower. However it is very hard to see a misalignment of the anchoragesystem with the tower feet or with the mouting base or, worst, a lack of plumb at ground level.9o prevent this type of problem, if your tower base is not too high suggest you to bolt on theanchorage system the first section of the tower mounting base. 9hat will ensure you that all isproperly set once sunk in the concrete. ndeed, in this way it will be much easier to check theplumb on a long panel or a rung of the mounting base, and make if necessary the smallad$ustments before the concrete hardens.

n anticipation of these small ad$ustments, prepare aside a wood board, a wood saw, ahammer, nails, a tape, a level, a ruler and a pencil. n case of trouble these accessories willhelp you to #uicky made a spacer for example, to ad$ust the alignment of the anchoragesystem.

9hen, as your concrete base will have to emerge at bit over the ground and that the concretewill stay li#uid for sometimes after pouring, construct a wood s#uare form around the hole ofapproximatively ?+ cm high 5/I6. 'lace a transversal board on top that will be put down on the

wood form. t will serve to temporary attach the anchorage system to prevent it to sink in theconcrete during pouring and until it hardens.

0riving of the hole ?.m deep 5>


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ground6. Eevel the top and check it is well horiontal. 9his is mandatory if the first tower sectionis welded to an horiontal plate like in the picture displayed above 5below left corner6.

f you cannot drive in the ground over @+ cm depth, what is common in hill areas and ranges,or if you want lighter foundations to support a small antenna 5P -+ kg, /+ lbs.6, you can preparea small hole +x+ cm aside and @+ cm depth only 5-+x-+x?-I6, place the feet of the towerinside and pouring the hole with concrete. Bf course in this case your antenna must be guy

wired.;uch small foundations are perfectly able to support a small beam 5up to -+ kg6 for years

under wind gusts over ?++ km3h 5>+ mph6. t cannot resist long times to winds blowing over?-+ km3h 5&mph6 on heavy or very long Dagis. n this case, to increase the security of thissmall installation suggest you to sink in the foundation a small wire netting, without to forgetthe maintain the tower with guy wires, but we will see that later.

n all cases check with accuracy the level and plumb of your base and anchrorage system.fyou don


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Among other manufacturers 9yco =lectronicscan provide you different kinds ofconnectors to permanently $oin your steel bars, bind them to rods or other wiring

systems.

ut for what reason the concrete could explode 8 9ower base concrete explosion is causedby an arc that takes place within the concrete between two pieces of metal that arenot electrically connected to each other. ;ince the concrete almost always has moisture, the

heat of the spark caused by a lightning strike expands the moisture and weakens or destroysthe concrete. y bonding the metallic elements of the tower base together, you achieve twothings 7 no potential for a spark within the concrete and you create a 4fer ground. A strapemerging off the concrete can then be use to ground your hamshack as we will see in thepages dealing with thelightning protection.
http://www.telecomosp.com/copper/groundhw.htmhttp://www.astrosurf.com/luxorion/qsl-lightning-protection.htmhttp://www.astrosurf.com/luxorion/qsl-lightning-protection.htmhttp://www.astrosurf.com/luxorion/qsl-lightning-protection.htmhttp://www.telecomosp.com/copper/groundhw.htmhttp://www.astrosurf.com/luxorion/qsl-lightning-protection.htm


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Assembling of the tower (I")

Although a tower is bulky and relatively heavy, itsinstallation on its base is not difficult at the condition to usethe proper techni#ue and good tools. 9he lightest towers ?+m high 5@@


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very hard sole with a deep pattern like any good range boots. Dou can also use work shoeswith steel inserts in the soles or even military Icombat shoesI.

For your safety it is of the uttermost importance that you borrow or buy a safety belt. 9his isin fact a generic term that we must divide in - elements 7 first, the leather belt, at least cmwide or -I, which length is ad$ustable to the perimeter of the tower like an ordinary belt. t isindependent of the security hardness 5but has to be attached on it6. 9hen you need either of a

strap snapor a safety belt with seat harnessthat you will attach around your waist. 9his is a?+ cm wide 5/I6 belt including a leather belt and some fasteners to attach various steel loops ortools.

From left to right, a full body harness with four 0rings 5- hips, ? back, ? chest6, a seat harnessbelt with a 0ring at each hip and a lanyard with gorilla hook. 0ocuments B(" ;afety elt.

9hese items come in various designs including the full body harness crossed on your chestand in your back. For your information a safety belt with seat harness cost about M?++. 9akealso some useful accessories like two steel loops50ring6 for the harness or the strap snap,several gorilla hooksor lanyards N+ cm long 5@ ft6, one or more solid bucketsto transportlittle tools or larger accessories on up the tower 5no more than ?+ liters or @ gallons6, etc.

9o put together the various sections of a tower three more accessories must enter in yourcollection of the most useful tools 7

a pulleye#uipped with a ring and encasted in wood or metal to prevent the rope to $umpout of the wheel. t will be attached on top of the gin pole 5see below6 or any convenienthook to lift heavy load on the tower.

a manila hemp rope. 9wice as longer as the height of your tower, it is used with the pulley.Always select the rope offering the highest resistance, and the larger supporting thestrongest strenght. A diameter of about - cm or +.I will make the $ob.

a gin pole. 9his is a special metallic pipe of about /m long 5?@


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t


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9he gin pole is of course useless 5or almost6 if you assemble the tower horiontally and erect itin position in pulling at ?-+ people on ropes.

:in poles are made to clamp onto rungs of Cohn (o.- to (o./towers like the W+W


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the services of ironworkers and of a crane, using a plaform attached to the shaft to assembleyour tower, and behind it of a good gardener !

Assembling of the tower (")

The guy wires

Cadio amateurs use guy wires to attach the towersupporting their antenna, but they usually know fewthings about the physical properties of these IcablesIexcepting that they prevent the tower of falling ! t istime to remind you some notions.

:uy wires attached at various heights along thestructure restrain the tower against the strength of thewind, translating the lateral force applied upon thetower in a downward compression force onto the base.

9herefore their tension must respect the manufacturerm high re#uire often to be guyed in the middle and on top toprevent too much swing, an heavy duty tower ?+m high 5@@m, &.-.&m, ??.&

?-m and ?&.??&./m e#uivalent to +?/ ft, ?-+ft, -/-N ft, @N/+ ft and & ft. 9hus, for a?+m high tower, which guy anchors are placed at a distance e#uivalent to &L of the towerheight, the longest guy wire is ?-.m long 5/? ft6 minus twice the @+cm re#uired for the thimbleand clamps, so we fall well in the ??.&?-m range. f the guy wire is a bit shorter than this valueit is in resonance on -+m and ?+mO if it is a bit longer it is in resonance on ?m and ?+m too. Atmidheight of this tower, the guy wire is Nm long minus twice @+ cmO here also we fall well in thegood lenghts.
http://www.astrosurf.com/luxorion/Radio/guy-wire-rohn-n3rr.jpg


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Above, from left to right, the installation of the rotative guy rings at W+D"AOthe rotative guy ringsat anchors sold byAntenna ;ystemswith their H@+ telescopic mastO the guy colar using tor#ue

brackets at W*@%.elow, =H; steel guy wires attached to their anchors at %/GA. (ote thesafety cable in IeightfigureI passing through the turnbucklesO a model of guy wire sold by thefrench company0*;C Antennasusing high resistance polyester protected with a ICislanI

polyamid $acket. 9he price of this guy wire is -.-+ Q3m, and at last the roof anchorage system at

W*@%.

:uy wires are generaly made of twisted steel strands able to support a pulling of severaltons. t can optionally be protected with a '"1 $acket. 9he amateurs should use the standardIham approvedI wire of =xtra High ;trenght grade =H; @3?>I or /.&mm thick. =xcepting forlight installations, do not use an aircraft cabling system as it sustains a strenght only &+L asstrong. (ew material allow also to build IplasticI guy wires, in fact made of high resistantpolyester protected with a polyamid $acket. 9hese new design are however more expensivethan the ordinary steel cable.

9o transform a steel cable in a guy wire, buy the re#uire metering to avoid the resonanceand fold back the open ends of the cable on a distance of about @+ cm 5?-I6 around a thimbleto prevent the wire of breaking due to the sharp bending. 9he excess of wire should be tightlyattached along the guy wire with three of more miniclamps, leaving a few doen centimeters of

wire free. 9his free end will be strengthened later, when all will be installed in the case youshould have to ad$ust the cable lengths, using a serving tool or pliers and wrapping a thinmetallic wire around the guy wire.

(ote that if you plan to pass the guy wire in a close loop to attach it to an anchor 5to a steelloop fixed on the colars attached on the tower or in the eye of a turnbuckle for example6, don


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allowing to ad$ust the tension on the guy wire without twisting the cable. ;elect a model whichIeyesI are compatible with the sie of the thimble or smaller than the sie of the bolts if yoyattach them to the loop of an anchor. n case of problem you can also use snaplinks. At last, toprevent the turnbuckle from working loose, it is recommended to pass a safety cable in afigureheight fashion in the eyes of the turnbuckle.

9wo methods for attaching guy wires to an anchor. n both cases to make a good anchor,the tilt should be about /J. (ote at left that the foot of the anchor is towards the tower,the force is perpendicular to the wires direction. At right the guy wires and guy anchor

and placed the same direction. 9he single e#ualier plate is an alternate method ofattaching two or more guy wires at the same anchorage point. n this second example, toprevent a potential break of a turnbuckle, the guy wires are secured with a safety cable in

figureeight fashion that is passed across the thimbles and the eyes of all turnbuckles.

The guy anchors and colars9he guy wires must be tightly attached, one side at several places on the tower, the other

side to guy anchors buried in the ground. 9he guy anchors should be made of stainless steelbars, ?m long 5/+I6 for @/ cm wide 5?-I6. Dou have the choice of the model 7 plane, in form of

Ebracket, like a stick with a loop at one end or even using tubing. 9here must have one ormore large holes on top to attach a heavy bolt or any other fixing means. f you need to attachmore than one guy wire to the anchor, buy an single e#ualier plate accepting @ or more guywires and attach this plate to the anchorage system.

First drive a hole ?m depth 5/+I6 and + cm wide 5-+I6 in the ground, if possible tilted at /Jin the direction opposite to the tower. Fill it with @+ cm 5? ft6 of concrete and sunk the anchorson ?3/ to ?3@d of their length. 9he emerging part of the anchor must not exceed ?+ to @+L ofthe anchor length. As displayed in the above graphs, you can either tilt the anchor in thedirection perpendicular to the pulling force, thus the feets of the anchor to the tower 5leftdrawing6, or place it in the same direction as the guy wires 5right drawing6. When the concreteis hard, fill the hole with soil and mark it well as an obstacle. n the dark you could forget it andfall head on on it !


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"ery few anchor shafts are galvanied. When drivenin the ground and partly sunk in the concrete, they cancorrrode. ndeed, the shaft itself acts as both anodeand cathode and its high conductivity makes it aperfect electrical path between the two parts. 9heconcrete and soil act also as two different electrolytes.We are thus in presence of chemical reactions ableweaken the metal resistance. n addition, the soil hasless oxygen $ust above the concrete anchorage andconse#uently, less resistivity. 9his phenomenoncauses corrosion that is most strongly in effect in theshaft underground area located between the groundlevel and the concrete. =xperience has shown that thisis the area most likely to deteriorate and cause thetower to fail. 9he anchor can also experimentcorrosion due to Istray currentI if for example yourtower is located close to electrified railways or if thereare welding or plating works. 9hese operations putalso direct current into the ground. 9here are productto protect your anchors against these effects. 9hey

consist in coating the shaft before driving it into theground.Anchor :uardfor example provide suchproducts against corrosion and very instructivepicturesshowing damage that might happen. 9hey areserious... 'roducts exist also to protect steel againstrust using cold galvaniing to name rite products.

A steel anchor driven in the groundand not protected against corrosion

will become rusty and see itsmechanical strength weaken. Dou

must protect it.

f the depth is limited to a few doen cm use halflenght anchors. Fill the middle of the holewith concrete so that ?3@ of the guy anchor is sunk in the concrete. (ote that freestandingtowers do not re#uire guy wires as the wind acts in compression and uplift upon the structure.

0o not attach immediately the guy wires. Attach first the guy colars on the tower assuggested by the manufacturer. For large towers they come often like rotating steel rings tobolt to the tower tubular structure. Without these accessories and more instructions, suggest

you a method similar to the drawings displayed below.

'lace around the tower, at each third of the heigth or at the middle and on top, a large colar.Dou can use either rotating guy colars or steel strips mm thick 5-I6, ?+ cm wide 5/I6 and -+cm 5I6 longer than the length of the tower sides 5so ?+ cm on each side6.
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2ost of the time to attach your guy wires to the tower, the manufacturer of your towerprovides you two or three rotating steel guy rings to bolt on the tubular structure. fyou don


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Installing of the antenna system ("I)

Eike the tower building, you must plan and thinkseriously about the way that you or maybe withyour team will proceed to the assembling andinstallation of the antenna system, what includesthe rotator, the supporting mast , the antenna andthe cabling system.

9his procedure is probably useless to place alight antenna that you can carry alone in one handand that does not re#uire hours of preparation toknow how to process, even if you have to place iton a sloping roof. 9his procedure rather concerns atypical bulky and large antenna that you cannotraise on top of a tower without assistance 5bothmechanical like adding a pulley, and human6.

;ee first if the tower or the antenna manufacturerhas not left some instructions. n all cases, here

also simulate at ground level the full installation. tis by far preferable to be warned before than haveto say sorry after !

Assembling a low band HF antenna onan **9owere#uipped with a ringrotor.

f you work with a team begin by assigning to each people a determined role according theirskills 7 what element of the antenna with what tool each people must assemble, who stands onground, why for, who climbs on the tower, at what time, who install the rotator, the antenna,who check the security and clean the ground, etc.

9he $ob must be divided in several steps 7 Assembling the antenna on the ground 'reparation of the area to raise the antenna and accessories nstalling the rotator and the mast nstalling the antenna 1onnection and fixing of the cabling system 5rotator and antenna6.

Assembling of an antenna is never adifficult task if you follow strictly theinstruction manual. With a screwdriver,pliers and a wrench this a $ob that lastbetween a few hours and...one or twodays.

When your antenna is assembled it istime to simulate the installation andimagine how you will raise this bulkyantenna there up as well as itsaccessories.

We will take the example of a standard

antenna assembled on top of a mast.9here are other solutions among whichthe installation of a rotating ring at anyheigth of the tower coupled with a 91ringrotorlike on the picture displayed atleft taken at(@CC. 9he antenna in fixedon the ring and all the tower rotates.

For a ordinary pylon, begin first by installing a gin pole or a simple pulley on top of the mast.f necessary, to avoid to lift a load too heavy 5over @+ kg, >+ lbs.6 attach a second pulley at the
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base of the antenna so that you can use all your weight when pulling, rather than the solestrengh of your arms. n all cases use a rope at least twice as long as the height of the tower.

9hen install the rotator on its platform and place the mast as described in the instructionmanual. 9o increase the resistance to wind and reduce the lateral force endured by the rotatoryou can add $ust above the rotator a thrust bearing as explained previously. Dou will attach allre#uired cables later. Cemember than the lower is the rotator the weaker are the constraints

that it will have to support.

At left, blue print of the main elements and siings of an antenna system. At center the rotator andthe thrust bearing installed at (+C. At right the installation of a typical rotator and its thrust

bearing.

%aising and fi&ing of the antennaAt last take the antenna. 9ie a rope around the balance point of the boom 5>+ cm to ?m on

each side or -@ft6 so that the antenna will be lift in horiontal position using the pulley5s6. f it isa long Dagi you can also lift it with the boom parallel to the tower but you will have moredifficulties once arrived on top to rotate it in position in both the vertical and the horiontalplanes.

efore raising the antenna verify that during the ascent it will not hit the tower or will not beblocked by any obstacle like the guy wires or the insulators. n this case you can build a ItrackImade of two ropes $oined over the tower 5near the pulley6 and tight more far than the guyanchors, thus forming a E over them, on which the antenna boom will slide to the top of thetower. ut it is maybe easier to attach two additional ropes to both ends of the antenna boomso that you can pull on them to move the antenna away for any obstacle.

When all is ready, clear the tower area from all useless tool and potential obstacle. 1heckthat the ropes are not intermingled and place them well apart, out of the antenna area and thepeople


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;ome steps of the installation of the @ stacked and phased encher ;kyhawk Dagis on top of a/+m tower in Cohn (o./ at W+D"A. :uys are a combination of +.-I =H; steel and >&++R

'hillystran.

0o never exert antagonist forces in the same time, like pulling strongly the boom toward youto avoid an obstacle and in the same time pulling it vertically. alance your strains because theboom is vulnerable to horiontal forces and might break apart, all the more if it is made of fiberglass. Avoid also that the antenna rotates during the climb in using the two additional ropes tiedand the ends of the boom to stabilie the antenna. Bnce arrived on top, one people is enough

to place the antenna and bolt it on its mast.When the antenna system is properly attached you can proceed to the installation of the

cabling system, the cables to power and control the rotator and the antenna feed line orcoaxial. Ceserve the installation of the ground system and the lightning protection for anotherday, but as soon as possible.

After this first installation attach slightly the cabling system on top of the tower then let it runsfreely to the ground. 9ake the time to place your cabling system in a flexible pipe ?+-+ cmwide 5/I6, the ends being protected with a piece of insulation. 0rive a narrow trench5excavation6 less than @+ cm depth 5P?


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each @+ cm 5?+J without pulling or binding the cable. ut conversely to not let the cables flap in thewind as they can be damaged under high winds.

"oilS, there we are, the antenna system and the tower are in place and work as expected !

think having nothing forgot.

Additional securityFor security reasons, to prevent

kids to climb on the tower, shield itslower part. ACCE published anarticle in the I6 and @ cm wide 5?.-I6. 9heyare fixed each + cm 5-+I6 on theleft vertical side and inside eachpanel. 9heir sie must be suited tothe diameter of your rungs. Dou canalso build these brackets in boltingtogether two Ebrackets upsidedown. ;o, for a s#uare tower your

need either of ?- Tbrackets or -/Ebrackets. 9hen drill one hole ineach plate and stick inside a bolt inorder to screw a removable doorknob from the outside.

1onstruction of a shield made of aluminium panels?.m long e#uipped of Tbrackets 5a Tbracket and a

doubleE versions are shown6. 9hey are installed on thelow part of the tower between the rungs 5see

explanations below6.

9o put the panels in place in the tower, move them from right to left and slightly tilted to youto $am the brackets around the vertical rungs then push them in position, they will stand up ontheir own weight. 9hen unscrew the doorknob. 9he panels must be difficult to extract for a kidalthough detachable in screwing the doorknob in the panels and taking the brackets out ofrungs in moving the panels to the side opposite to the brackets 5right6 and slightly tilted to theoutside.

0o not forget also to ground your tower and the antenna, and to install a lightning protection.

I'layingI with high voltage and current, this time this is not a $ob that has room forexperimentation...

To read'All about ightning protection

Cemain the maintenance. 1heck the state of your installation regularly from top to bottom,the antenna of course, but also the rotator housing, the fixings 5bolts, anchors, etc6, the base ofthe tower and the tension of guy wires. 1heck whether an hardware is missing, spots of rust,
http://www.astrosurf.com/luxorion/qsl-lightning-protection.htmhttp://www.astrosurf.com/luxorion/qsl-lightning-protection.htm


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structural defects like cracks or bindings. Fix immediately any problem, reinforce if necessarythe concerned element before it becomes a danger.

At last, think also to the dismantling of your tower. 'roceed like we did but in reverse order.For the bulkiest installations it is preferable to entrust this task to a specialied company thatwill do the $ob using a crane to minimie the risks of accident.

:ood luck !

Take care assembling an antenna system

f you are not confident and used to erect antenna towers, do notentrust the $ob to close friends or socalled skilled radio amateurs...Dour life and the one of your friends is more important that sparing afew money in doing the $ob yourself without competences.

Here is the comments of Gack, an ironworker in this regard 7 Ithereare some places and some $obs where if you make a mistake, people,either yourself or others or both, will be killed. Amateur Cadio is notdefined as one of these occupations, and no amateur has anybusiness working aloft with rigging and e#uipment unless he wasproperly trained in that field. 9hat certainly doesn


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happen between +?+ meters 5+/+ ft6. After that, you

Assembling Your Antenna System

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