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Aerial Pole and Bracket Tests

Poles & Brackets Tests

A little flex in an aerial pole is no bad thing, it helps take some of the shock force out of the wind loading, but satellite poles must be rock steady if you are keep the dish focused on that little “geostationary” transmitter 22,000 miles above the Equator.  Thus we stock ultra strong satellite masts, 5ft x 1.5” x 16G, 4ft x 2.0" x 14G and 8ft x 2.0” x 14G in alloy and a 6.5ft crank in hot dip galvanised 1.5in diameter steel. They are equally suitable as extra heavy duty aerial poles. Most Sky / Freesat dishes will also fit on a 2" or 1.5" pole (though you will need a V bolt * ), but a few of the older ones [fitted with the little "L" pole] will only take 1.25" poles. Check which type you`ve got !


* Most previous models of Sky / Freesat dish took a 2in V bolt but the Mk 4 introduced about 2010 takes a non standard 2.5" V bolt. On the Mk4 dish Sky also changed the design of the LNB fitting as well so older LNBs won`t fit it. Now that`s either crap design, or they were just being bleedin` awkward, it`s one or the other, take your pick, don`t you just hate Sky ?

Particularly since switchover aerials in loft aerials can work OK in reasonable signal areas and we sell the above “Loft Kits” to mount the antennas. You can just suspend the aerials from string though this can be awkward when aligning the antenna ! The loft kits come with a 2 way surface bracket, these mount perpendicular or parallel. Some people use the latter (with large jubilee clips) to attach small items, e.g. CCTV cameras, to lamp posts or similar, also of use for doing this are the multi angle brackets.


Although some people use loft kits to mount installations outside, we don`t recommend it* and the accompanying picture illustrates why ! Still, at least the flimsy Bacofoil aerial matches the under specified pole/bracket......


* OK for an FM/DAB dipole (in sheltered areas) ?

It`s called a loft kit for a very good reason, it should be used in....... A LOFT ! Cowboy`s bendy pole

Steel poles. Eventually, they all come down....  (Note the 6” pressed brackets)


Then we have Alloy poles. Not only are they rust free but they will flex slightly in the wind (some think this absorbs some of the shock loading) and they`re lighter as well. Both of these will help in putting a little less strain on the bracket, and on your brickwork....  Unfortunately alloy masting is more expensive and (size for size) is slightly weaker than steel unless the appropriate gauge / diameter is used.

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This is one of my favourite pictures on the entire site, in fact I like it so much it`s also on the Sales page !  Nothing shows so vividly the differing qualities of materials used in this trade. Remember that the 1” steel pole was originally galvanised, although as we have already seen it was only “Pre-Galv”. If one looks carefully one can see where the wall became so thin that eventually the pole snapped in the wind. Compare the two alloy poles, the 1” pole`s smaller size and thinner wall are immediately obvious and a 6ft length weighs about 450g. The 1.25” x 16 gauge pole`s superiority is plain to see and a 6 foot length of this pole has a weight of around 750g, that`s 67% more metal....


 In normal usage it will never fail.


Let`s compare the three commonly supplied varieties of 6 ft alloy mast. They can be either straight or of the cranked/swan neck variety. The first type is 1" diameter x 18 gauge, they are the equivalent of 3” fence posts and we would not use a 6ft pole of this type for a TV aerial under any circumstances. In fact I am prepared to say publicly that any installer using such a pole (particularly with a large aerial) should be wearing a Stetson. Having said that, if the installation shown below was done by the house owner one cannot necessarily blame him. I was in a DIY shed the other day and the only 6ft pole they sell is a 1”x 18 gauge, we call them “B & Q Specials”, and they certainly wouldn`t have a pole lifetime warranty !

I wonder where the installer who fitted this 6ft x 1” alloy pole tied up his horse ?

And he (or she !) has only used a 6” chimney bracket.


See our tests of Poles, and also Cowboys` Locker


Incidentally, why has Roy (as in Rogers, as in cowboy) fitted a 5 element DAB aerial ?  Very few people actually need one of those, could it possibly be was so he could charge more ?

Steel poles, they`ll all come down, sooner or later.... Steel poles, they`ll all come down, sooner or later....  2 Steel poles tend to rust from the inside......

Steel Poles rust from the inside !

Chimney brackets

Coffee & Cream


Do you really want that

on the front of your house ? ! ?


It isn`t uncommon to see rusting steel brackets fitted on the apex of rendered walls with huge rust stains stretching out beneath them.... All for the sake of a bit of decent galvanising. The latter is just what you get on a galvanised welded bracket and these are the only type we sell. None of your thin finish "Pre-Galv" here, this is "Hot Dipped" galvanising and it is very impressive. We`ve seen brackets that have been up

20 years plus without a trace of rust staining. In fact we`ve got an experiment running where we`ve actually tried to file off the galvanising finish (on a section of bracket) and left it outside in the rain.

It hasn`t rusted at all in nine years !


I really wonder how anyone, no matter how big a bodger they are, could possibly contemplate using a painted bracket. They must be tighter than a camel`s arse in a sandstorm.......

Remember that it is totally irrelevant how strong the bracket(s) are if the

bodging installer only uses two wall screws , so check he uses four !


The picture above shows

a 6”x 6”, a 6”x 9”, and

a 9”x 9” wall bracket.


All our brackets are of welded construction and “Hot Dipped” galvanised, also see “Wall or Chimney ?” )


Note ! Remember to order the V Bolts with the brackets ! We also sell the wall fixings for our brackets.

There are two opposing views as to which should go at the top. The K is obviously the more robust bracket and the received wisdom is that this should go at the bottom because, being further down, the wall is stronger there. However the top bracket is probably under the most stress (certainly if the wind is blowing the pole away from the wall) and so some think the K should go there instead !  Basically one has to work out the relative importance of the two factors for the particular install being undertaken. For an install at the peak of a gable I would put the K at the bottom, whereas on a strong flat top wall I`d put the K at the top.

Basically it`s six of one,

and half a dozen of the other,

But, if in doubt,

put the K at the bottom !

In the left hand picture we have a 6”x 6” and 8”x 8”(mitre) chimney bracket, and the right hand picture shows the contents of a “Lashing Kit”. The latter includes 5m of pre-terminated wire, 2 x 1.5” V bolts and 6 plated washers (4 x M8 + 2 x M10). As far as we know this is the only pre-terminated lash kit on the market to be supplied with washers. If your chimney is bigger than 5m we can supply a 10m length of the 7 strand galvanised lashing wire. This can be either used instead of the supplied length or used to extend it . Do not confuse this with thinner catenary wire, 7 strand lash wire is approx 3.7mm in diameter and weighs about 65g per metre.

Cheap pressed bracket next to welded bracket

The picture illustrates the difference in construction standard between a pressed Chimney bracket and a welded type. Perhaps even more striking is the amount of rust on the “Pre-Galv” pressed bracket.

Note the “failed” steel pole.

Also see “Wall or Chimney Bracket ?”

Wall brackets T & K brackets T and K brackets

For aerial poles up to 3ft supporting small or medium size antennas we recommend and stock the 6”x 6” bracket (see picture). It is important to stress that a 6” welded bracket won`t (usually) “fail”, it`s the masonary which will go first, because a 6” bracket only spreads the load across the corners of two bricks, see picture on the left.


For other installations using poles up to 8ft and aerials up to the size of a DY14 we sell the 8” mitre bracket. If an XB16 is fitted with an 8” mitre we`d go up to a 6ft pole.  An 8” mitre usually covers three bricks and to a greater “depth”, see picture below left. The mitre bracket should also be used if your brickwork is in poor condition.


Ten foot poles usually require a pair of brackets.


See bracket to pole recommendations



Bertie Bodger`s “Bang Bang” Bracket


Note how the masonry has been pulled out, and that`s out of a wall, not a (weaker) chimney stack......

Bertie Bodger`s Bang Bang bracket 1 Bertie Bodger`s Bang Bang bracket 2 Bracket too small for pole/aerial.... 8 inch mitre chimney bracket in use, QUALITY

An 8 inch mitre chimney bracket in use.

Note the fact that the loads imposed by the installation are spread over three courses of bricks and to a greater depth than the simpler types of chimney bracket, compare to 6” bracket install. This really is a fantastic product, note the pre-terminated lash wire (see below).

Pair of Heavy Duty Chimney

Brackets.   These are exceptionally strong but must be used as a pair with a separate lashing wire each. These brackets come with 2” V bolts as the standard 1.5” size will not fit. Note that the pole can be mounted either side.

Wall or Chimney Bracket ?


The crucial difference between a wall bracket and a chimney bracket is that the former is screwed to the wall whereas the latter is lashed to it, in fact they are sometimes referred to as lashing brackets. It is vital that this difference is appreciated because the main reason that anything bolted to a wall has any strength is the bulk of the brickwork above (and around) those to which it is actually screwed. Unless a chimney is of large proportions it is unlikely that there will be sufficient bulk/weight in it for a screwed fixing to be adequate. The answer is to use a lashing wire to tightly hold the bracket onto the corner of the chimney. For the same reason mentioned above, there should be a few courses of brick left above the installation. J-bolts are used to provide the required tension, though the lashing kits we stock use a pre-terminated eye-bolt on one of the ends so as to simplify/speed up the install. We supply an instruction sheet with the Lash Kits we sell.      


Shared chimney ? What to tell an awkward neighbour……


36" T and K brackets

Also see our Pole Tests (including T & K brackets)            

Quality pole, next to crappy poles. Pre-terminated lash kit, c/w washers.....

Poles / Masts


Who would have thought that something as simple as a TV aerial pole could have so many different types with such wide variations in quality…...


Size for size Steel poles are stronger than alloy poles, so why don`t we stock them ? Well, in the first place steel poles aren`t actually that much stronger than alloy ones, but more importantly, even though they`re galvanised they rust. How come ? Virtually all steel masting sold in this country is "Pre-Galv", that is to say the metal is pre-galvanised before being formed into a tube. On Pre Galv products the galvanising is much thinner than "Hot Dipped Galvanising" and furthermore the weld line up the side of the tube is generally just painted, if that….  Incidentally, steel poles will generally rust from the inside as shown in the picture below. Finally all Pre-Galv products have an exposed unprotected edge where they are cut or stamped out and this is where rust usually starts. Don`t get me wrong, a steel pole will take years (many many years if it`s hot dip galvanised ! ) to rust through to the point where it becomes so thin that a strong gust of wind will break it, but eventually, it will come down.  


See our tests of aerial / satellite poles and brackets and our our pole lifetime warranty.



Heavy Duty chimney brackets, they`ll never fail....

The first dimension in a bracket size is relevant according to the length of the pole which the bracket is expected to support. A longer pole will generate more leverage on the bracket (and the wall.....) and therefore a bigger bracket should be used. The second dimension is the length to the end of the bracket and it is this from which the stand off of the bracket is determined


There are basically three main variants of the standard type brackets used on many smaller installation jobs, that is to say the 6"x 6" bracket (wall or chimney mount). The cheapest of the three is the pressed steel type. It is galvanised but it is of the “Pre-Galv” type. Although this is far preferable to just being painted, it will not remain rust free anywhere near as long as a "hot dip galvanised" bracket would. As the name implies it is just a bent piece of metal sheet (typical thickness 2.5mm) and it is not in the same class (strength wise) as a welded bracket, in fact they can even be bent in imaginative ways......


See Pole & Bracket dimensions.

Definition of a bracket`s stand off Pole strength tests

Finally we have the third type and the only type we sell (straight or cranked). This is the Rolls Royce of the 6ft aerial poles and they are 1.25" x 16 gauge (1.6mm) alloy,

In normal usage, they will never fail.

Why doesn`t everyone use the latter type of  pole ?

Well, two main reasons spring to mind :

They`re more expensive and DIY shops don`t generally tend to sell them.

If a weaker pole (particularly a 6ft x 1") is installed by an aerial rigger, they probably want some "repeat business".


The second variety is the 1.25" x 18 gauge (=1.2mm) aerial pole. They are a bit stronger than the 1” type and fine for smaller aerials, provided the top V bolt is not over tightened which can crush the tubing and eventually lead to failure.

Bodge 2

It must be stressed that T & Ks are used to gain more stand off, not because they`re stronger than a pair of smaller brackets, particularly if the latter are of the welded variety. So long as the pole`s V bolts will fit the bracket there is no reason why two  6x6, 6x9 or 9x9 brackets cannot be used for a 10ft or even 16ft pole. In fact, arguably, the strongest (wall) installation would be using two 9x9 (all angle iron construction) wall brackets. Quite apart from anything else a pair of smaller brackets will have eight wall anchors and four V bolts to secure the pole, as against only five anchors and two V bolts of the T & Ks. Actually, two 9x9s may be the strongest install towards/away from the wall, but in a sideways direction I reckon two 12" Ks may well be the strongest. An area for debate methinks.

T and Ks are also available separately if needed. Two Ks are obviously a bit stronger than a T and a K, but it must be admitted there are relatively few installations where this would be of consequence. After all, the pole would usually fail before the bracket anyway !  On the other hand, each K does have 3 wall anchors, whereas each T only has 2, and that may be significant under certain circumstances.


But do you really  need T & K brackets, when cranked / Supercranked poles are available ? !


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Mounting Aerials on Fascias ?

We sell 3ft & 6ft poles both at 1.25” x 16G.

The 8ft pole is 1.5" x 16G.

Our 10ft poles are either 1.5 inch diameter or 2.0” diameter (both 16G = 1.6mm), the latter type should be used for larger aerials (e.g. XB16s / XB22s) or in exposed locations.

We also sell 2” Pole Couplers, e.g. to join two 2in diameter poles together however we would not normally advise coupling two 10ft (16G) poles together. We`d suggest using an 8ft (14G) "satellite pole" and coupling that to a 10ft pole, placing the thicker walled pole at the bottom (think Eiffel Tower).

The 12ft pole is 2 inch but the thicker 14gauge (= 2mm).


Then there are cranked (or "swan neck") poles (see picture) which are sometimes required if the pole has to clear an obstruction, the eaves for instance. You can use a bigger bracket instead of, or as well as a cranked pole. One should always leave a gap of about 2" to prevent high winds causing the pole to bang against the fascia and also to facilitate maintenance of the latter. Cranked poles can also be used to move an aerials position laterally if this is required to give the antenna more of a clear path to the transmitter (say to avoid another aerial pole) or to avoid an “RF dead spot”.


Our 3ft cranks are 1.25” diameter alloy and as far as we know we are the only people to sell 3ft these, we go the extra mile because we love quality, fantastic !  These poles (and the 6.5ft x1.5in cranked satellite pole) are so strong  they are even suitable for mounting satellite dishes up to 60cm (or more in sheltered locations).

We also sell 6ft cranks at 1.25" x 16G (alloy) and 10ft cranks at 1.5” x 16G (hot dipped galvanised steel), though if using one of the latter in an exposed location with an XB16 or an XB22 I`d be tempted to chop 1ft off the end of it.

NB Overall clearance on a 9”x 9” wall bracket with a cranked pole is approx 17”


For those requiring more “off set” we have a 10ft Supercrank pole in 1.5” x 16G hot dipped galvanised steel. These are particularly suitable for buildings with large overhangs on the fascias. Fitting these is much neater than huge T & Ks and a straight pole. The 10ft Supercrank pole is sometimes used "upside down" to crank a pole back over the roof if birds` little presents to you are a problem.......


Finally we stock a Right Angle Crank, which has an off set of 21 inches. The right angle crank, along with the 6ft L section, is “pre galv” steel. Both are 1.25” diameter, the wall thickness on the former is 16G (1.6mm) and the latter is 18G (1.2mm).


All offsets are approximate, if this measurement is critical phone to check the exact figure.

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Bodge 1

The simple answer is that it`s bad practice and it shouldn`t be done unless there is absolutely no alternative. A bracket mounted on a wall (with the appropriate pole to clear any overhang) is far stronger than just attaching it to a fascia or bargeboard. Furthermore screwing brackets to wooden boarding greatly increases the chances

of rot setting in and makes it more awkward to repaint them as well. Finally, many people will eventually have UPVC replacement fascias fitted, and then the bracket will need moving anyway.


I don`t even want to think about anyone actually screwing an aerial to a UPVC fascia.........

Bracket and pole dimensions How to terminate the other end of the lash wire Pre-terminated lash kit
aerialsandtv.com

Cranked poles


Satellite poles


Loft kits


Pole recommendations


Seam welded v extruded alloy poles


Use of longer poles

Poles and Masts  incl :

Brackets  including :

Loft bracket mounted parallel Loft bracket mounted perpendicular

Shown above left are a pair of 12”and 24” T & K wall brackets, 18” and Heavy Duty 36” are also available. Like all the brackets we stock they are welded and “Hot Dipped” galvanised.

Summary of which bracket to use with which pole / aerial


It is good practice to follow these recommendations, in addition they must

be followed to qualify for the lifetime warranty on our brackets.


A 3ft pole can utilise a 6” welded wall bracket (6 x 6” or 6 x 9”) for any size aerial.

If mounting on a chimney an aerial up to the size of our Yagi18 or DY14 can utilise a 6” bracket but an XB16 / XB22 should use an 8” mitre, to be on the safe side


A 6ft pole can be used with a 6” welded wall bracket for any aerial up to a Yagi18 though, as always, one must make sure the wall anchors are tight. For larger aerials we would use a 9”x 9” wall bracket especially in exposed locations. Since cranked poles put a bit more strain on the bracket it may be advisable to go for a 9”x 9” bracket with a crank, and definitely so if fitting a Supercrank pole.

An 8” mitre chimney bracket should be suitable for all of our antennas on a 6ft pole.


An 8ft or 10ft pole should be suitable for use with a 9 x 9” wall bracket on any aerial, apart from an XB16 / XB22, provided the wall anchors are tight. I would probably advise the use of two brackets (or T & Ks) with an XB16 / XB22, particularly in exposed locations

An 8” mitre chimney bracket would be suitable for a small aerial (e.g. our DM log periodic) but anything larger should use a pair of chimney brackets. These would usually (but not necessarily) be the H/D type spaced at about 12”, or more for an XB16 / XB22 antenna.

I would be wary of fitting a pole of 10ft (particularly with a large aerial) on a small chimney with any size of brackets.


A 12ft or 16ft pole on a wall requires a pair of brackets (often T & Ks, but not necessarily) for any size of aerial and they should be spaced at least 18” apart, or more for a larger antenna.

For chimney mounting a pair of lash kits and two brackets should be used. The latter would usually, but not necessarily, be the H/D type. The spacing should be at least 20” (or 30” for a large aerial) for a 16ft pole and I would be even more wary fitting it on a small chimney !  It should be pointed out that it is very rare to have to fit a 16ft pole on a chimney.


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If mounting an aerial on a chimney which is being used, or ever likely to be used, I`d recommend a cranked pole to try and get the aerial as far away from any smoke and/or fumes. The smoke won`t affect the signal, but it isn`t good for the aerial so I`d also place the aerial on the upwind side (of the prevailing winds, usually from the S or SW) if at all possible. Bear in mind that a smaller end mounted aerial (like a Log Periodic) can sometimes be mounted below the height of the chimney pots.

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Close Up of lash wire terminations

On the left is a “pre-terminated” end, our stock lash kits come with one end like this. The one on the right is made up by the installer, with the lash wire at the correct length to fit round the chimney and hold the bracket tightly on the side of the stack.


See Installing a chimney lash kit.

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When deciding how strong to make your install remember that the weight of the aerial/satellite/weather station is almost irrelevant, it`s the wind loading that counts !


Remember, if you`ve got a big aerial on a long pole and it`s accessible, if particularly high winds are forecast it is sometimes possible to temporarily lower the install for the duration of the storm.

Brackets


Brackets are classified according to their size (from the top pole clamp to the bottom one) and their stand-off, that is to say the distance from the wall (or chimney) which the pole will be when "in-situ". The latter may be significant if the pole has to clear an overhang above it  but bear in mind that these dimensions are to the end of the bracket, 3" to 4” will be "lost" in accounting for the width of the pole / clamps, see picture below.

But always remember you don`t have to use a huge bracket if you can use a cranked pole !


When installing a wall bracket always leave 2 to 4 courses of bricks above the install*, and try to make it 4 to 6 courses if installing the aerial on a gable.


* Depending on the size of the aerial and the length of the pole, and whether you`re using a Black and Decker or an SDS hammer drill to drill the holes......

When it`s called a wall bracket, that`s for a reason. They`re not meant for chimneys. That would be a, what do they call it ?   Ahh yes, a chimney bracket.......    (pictures courtesy of Vision)

Some installers fit “Self Supporting Brackets” (sometimes called “Bang Bangs”) which do not utilise a lashing wire. They have two “L“ shaped pieces of metal which are hammered into the mortar between the bricks, hence the term “Bang Bangs”. Unless access problems are severe (and two are utilised to increase the support) most riggers know they`re a bodge because the strength of the install depends on the mortar around just two bricks at the corner of the stack.


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Question : Why didn`t the installer use galvanised brackets ? Answer :  He`s a tightarse !

Bracket Dimensions

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We are more than willing to give advice to those actually purchasing from us. Could those only seeking information please just find the answer somewhere on this site, or ring an aerial installer local to them, or call the reception advice phone numbers.

Weather Station Installations  including : Joining poles of different diameter


Pole / Mast Caps


Health & Safety Disclaimer


Wall Anchors (Wall Fixings)


Pole Clamps and Couplers  including : V bolts, saddles & pole clamps


Aerial Clamps & Cradles  including : Multi angle bracket


Avians On Your Aerial


Poles, Brackets & Galvanising on test


Also see our pole lifetime warranty and our bracket lifetime warranty.

Poles and Brackets

Subjects on this page are listed in the following order :

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Pole Recommendations


Generally any of our poles are suitable for any aerial, but, bearing in mind wind loading considerations, we have a few specific 4" fence post recommendations, and these are to be followed to qualify for our pole lifetime warranty.


We do not normally recommend fitting any TV aerial or multi element FM/DAB aerial on a 6ft x 1in pole although you might be alright with a DM18Log or an FM or DAB dipole. Six foot x 1in poles are excluded from our pole lifetime warranty.


If fitting an XB16/XB22 aerial on a 10 ft pole we only recommend the 2" variety, the same applies if fitting multiple aerials on a 10ft pole. An XB10 or DY14 aerial would be unlikely to break a 10ft x 1.5in pole but it may move around a bit in a high wind......

The 8ft x 1.5" pole is pretty much strong enough for any aerial though, as is the 12ft x 2in 14gauge.


We don`t recommend fitting XB16/XB22 aerials on 10ft cranks (or 10ft Supercranks) unless cut down by at least one foot, and preferably two foot in exposed locations.


The 4ft x 2in satellite pole is suitable for dishes up to 1m but in exposed locations we only advise use of the other satellite poles for dishes up to 60cm.


Any of our satellite poles are suitable for any aerial (or aerials) under any conditions.


When using a pole coupler we do not recommend coupling two 10ft x 16G poles together unless it is a small aerial, i.e. up to 50N windloading, e.g. a DM Log. Coupling a 10ft pole to an 8ft satellite pole (the latter at the bottom......) is suitable for an aerial up to an 100N windloading, e.g. an XB10. For XB16s/XB22s the maximum length pole we would recommend coupling on top of an 8ft satellite pole would be 8ft, and less in a particularly exposed location.

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#LoftKits

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Maybe (well fitted) plug type wall anchors aren`t so weak.......

Results of pulling out one of our 50mm M8 wall anchors using a tow rope attached to a car !

Pole Clamps


The most basic clamp is the "V bolt" which bolts the pole to its bracket and these are available in M8 x 1.5", M10 x 2.0" and M10 x 2.75" sizes (all internal diameter) .

Note, all our V bolts come with washers.

If replacing a pole even the tightest aerial installer would use new V bolts, mainly because it`s far easier to just hacksaw off the old Vs rather than try and undo the nuts on rusty ones.  

If you have to use V bolts larger than 1.5” make sure you check they will fit the bracket. Some brackets, esp 6" types, only accept 1.5" Vs. You may have to drill an extra hole yourself, or get the file out !  

When using V bolts I would tend to tighten the bottom one more than the top one because if you crush the wall of the pole you will significantly weaken it just at the point where it`s under most strain. In our tests all the poles (unsurprisingly) failed at this point.

The bottom V bolt can be done up as much as you like to ensure the pole doesn`t twist in the wind. Sufficiently tightening the bottom clamp is particularly important if using an end mounted aerial (though we don`t actually recommend end mounting aerials for outside use, not large aerials anyway) or a cranked pole, and especially a Supercrank pole.  Crushing an 18G pole is rather more likely than with the thicker 16G or 14G versions (we only sell 16G or 14G poles).

Also see our Pole Tests (including wall anchors)

V bolts, c/w washers !

Wall Anchors (Wall Fixings)                 (“Rawlplugs” v “Rawlbolts”)


The method used to fix a bracket to the wall is actually a subject of some debate.

Should one use wall anchors of the metal “Rawlbolt” (sometimes called Shield anchors) type or (large versions of) the plastic “Rawlplug” variety ? There are arguments on both sides. The Rawlbolt type fixings can undoubtedly exert more grip on the brickwork, but there is a far greater risk of splitting the masonry if you tighten the fixing too far. Furthermore if one uses an M8 Rawlbolt type fixing the hole in the masonry must be 14mm, and that is a pretty big hole. The obvious answer is to use a smaller one, but even an M6 Rawlbolt requires a 12mm hole and if one gets down to using a Rawlbolt of that size then it`s debatable if it is any stronger (overall) than a well fitted Rawlplug  type fixing. The latter is the type that we stock. The critical point with this type of fixing is that the anchor must be a tight fit in the masonry and be capable of taking a decent level of torque when tightening up. Rawlbolt type fixings are more forgiving in that they can expand further to compensate for a hole which may be a little too big or masonry which may be a little soft. If you do find yourself in the position where any wall fixing won`t tighten up, try removing the screw, hammering some wood slivers (e.g. matchsticks) into the hole to pack it out then replace the screw. If it still doesn`t tighten up sufficiently hammer more wood into the screw hole and repeat the process until the screw will tighten up OK. At one time packing (just) wood in the hole was actually how it was done. Remember, sufficient tightening torque is the name of the game, and providing enough can be applied to a Rawlplug type fixing it is highly doubtful that it would ever fail.

Finally, always remember to ensure that any wall anchor is screwed into the brick, not  the mortar. We once tried pulling one of our M8 Rawlplug type anchors out of the wall (with a tow rope attached to a car) and it pulled half the brick out with it ! (see picture below)

We sell wall screws in standard 50mm and the longer 75mm , the latter is generally used when render on the surface of the wall stops the standard 50mm screw/plug seating fully into the brickwork. Both are supplied with an M10 plug (which requires a 10mm hole drilling in the masonry) and an M8 plated washer.

The SWL (i.e. the force required to pull it straight out of the wall) on a well fitted 50mm screw/plug combination is about 45Kg, though the maximum load would be around double this. A  75mm screw and plug combination would usually have a higher SWL than the 50mm but only if there is no void in the brickwork. If, when drilling the hole, you feel the drill bit has hit a void deeper within the brick (newer bricks are more likely to have voids than older types) then our advice is to fit the shorter fixing so the plug expands into solid masonry.

Rawlbolt and Rawlplug type wall Anchors

Comparison of Rawlplug type and Rawlbolt type wall fixings.


Note the collar on the wall plug, these help to ensure the plug fits the hole properly and tightens up more easily without deforming.


Our wall anchor plugs have collars !

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They could call it the “Rod Hull Rule”.

It`s pity he didn`t fall on that bleedin` bird isn`t it ?

Or perhaps he did ?

Is that a tautology ?

*

Disclaimer

Note. There could be some Health & Safety Bollocks ruling* about trying to fit your own aerial, so consider this sentence to be a concession to that.

But also see basic ladder safety.......

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Flimsy aerial, only suitable for small birds......
Bacofoil Aerial

In addition we stock clamps to attach poles to each other, either a 2" x 1" or a 2" x 2" is available. The latter type will clamp parallel or perpendicular but the smaller one only perpendicularly. If two poles of any length are to be clamped in parallel it is normal practice to use two clamps, also see aerial clamps / cradles and pole couplers.

Avians On Your Aerial


Assuming that their aerial is sufficiently strong I don`t suppose most people mind birds perching on them. After all they may well be tired and shagged out following a prolonged squawk.

However if your aerial is situated over the drive where you park your car, and the aforementioned bird is doing what birds do (or should that be doo doo) then you might not be so hospitable.


You have a few options, apart, of course, from buying a cat with an interest in aerials.


The best line of attack is more a case of defence, and that is to mount the aerial* where the avians gifts to you won`t cause a problem. Generally speaking this involves erecting the aerial over the roof. If it`s on a chimney then that would normally be the case anyway, but if it`s installed on a wall you might need to use cranked pole (usually a “Supercrank"), or an L Section pole or even a side pole to shift the antenna back over the roof. Use of a side pole would probably require a 2x1 clamp and a suitable length of 1” pole.


If all of the above ideas are unsuitable to solve your wildlife worry you could try using fishing line or tie wraps. String the fishing line across the top of your aerial, either from the top of the reflector down to the middle/front elements, or from the pole above the aerial to the same points if that is easier, as it would be with a Log Periodic type antenna.

Tie wraps can also be used to agitate the avians, leave the uncut lengths poking skywards, they don`t like it up `em, apparently. The advantage of using fishing line over tie wraps is that is looks a lot neater. After all fishing line is supposed to be invisible (to fish at any rate).  Make sure the fishing line is UV resistant though.


* Obviously you have to make sure that your aerial is sturdy enough to withstand our feathered friends sitting on it. What you don`t want, is a Bacofoil aerial !

Aerial on a side pole, for the birds

Aerial Clamps & Cradles


An aerial obviously requires a clamp to attach it to the pole and the vast majority of aerials come with a clamp, all the aerials we sell certainly do. Most aerial clamps will accept pole diameters up to 2”, and again all of ours will do so.

Ideally all medium or large aerials should be centre mounted (unless installed in the loft) and cradles are generally used to add support.

In addition cradles move the antenna away from the pole which, for a centre mounted aerial, is particularly important when vertically polarised.


Tilting clamps allow for elevation of the end of the aerial to help achieve the most accurate alignment but more importantly (the possibility of) reducing interference. All our aerials come with tilting clamps except the Log36. The manufacturer`s of the latter maintain that one is not

required for Log Periodic type aerials, though I`d certainly disagree if using one on a boat or caravan.....

Aerial cradle and clamp

The aerial on the above is aligned onto Cow Hill transmitter which is high up on a hill (would that be why it`s called Cow Hill....) next to Fort William which is down in the valley. It must be said that it is rare to require a clamp to tilt this far !  

Incidentally I don`t like the install, it`s on a fascia and it`s a Contract aerial. Contract aerials don`t come with tilting clamps, so did the installer buy the clamp separately ?  Why not just buy a decent aerial, with a tilting clamp, in the first place ? ! ?

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Tilting aerial clamp

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Weather Station Installations


Our customers tell us there are a few different priorities when it comes to mounting weather stations. The wind loading of weather stations is generally much less significant than it is with aerials and satellites, particularly large aerials and satellites. That is to say you don`t need to worry so much about using larger brackets and stronger poles in case the install gets blown down in a gale, so that`s good news. On the other hand we`re also told that having a weather station on a bendy bracket and pole can induce errors in the rain gauge measurements and wind speed readings. So, from that point of view you actually need stronger (i.e. more rigid) bracket and poles !  Anyway, I`m pleased to have clarified that for you........


On the right we have a neat weather station installation which was put up by Nick Beer. He`s mounted his “Davis Vantage View” weather station on a Supercrank pole which is itself mounted on a 9x9 wall bracket. Nick reports that the station is stable in use and provides accurate readings. This install gets the station well away from the walls and/or roof, I`m told it`s a good idea to have the weather station at least 6ft above any wall or building to ensure maximum wind speed accuracy. Note how Nick has painted the bracket and the lower part of the pole the same colour as the wall so as to be as unobtrusive as possible (also see low profile brackets) though it`s still worth using a galvanised bracket  because it won`t rust when the paint wears/flakes off.


Also see “a pole on a post”.

This Multi Angle Bracket has got to be just about the most versatile ever. The plate clamps to a pole (between 1" and 1.5" diameter) onto which can be attached anything from a CCTV camera to a tube (up to 2" diameter) using an additional clamp, see below. Note : this product is not meant to join big poles together or mount large aerials in exposed locations, it`s to attach, well just about anything of relatively low wind loading, and at an angle if required.

#MultiAngleBracket

On the left we have the basic multi angle bracket, on the right its versatility  is demonstrated here with a simple clamp bolted to it.

A 2in diameter pole on a pair of 12in T&Ks

Mounting Aerials on Fascias ?


Wall or Chimney Bracket ?


Summary of which bracket to use with which pole/aerial


Bracket Dimensions

#Low_Profile_Wall_Bracket

T & K brackets are designed to increase stand off but what about when less stand off is required ? ! ?  For those applications use the Low Profile Bracket. These brackets accept poles up to 2 inches in diameter and the stand off is approximately 1.5 inches. They are supplied with a sledge and bolts so you don`t need to separately order a pair of V bolts. You would generally use them in pairs unless it`s a small aerial on a short (3ft or less) pole. Because the stand off is so small the brackets are actually very strong despite only being 1.5mm pressed steel (“Pre galv”).

Note that these brackets don`t allow any adjustment of the poles stand off so should only be used on a flat surface.  (Link)

Obviously the spacing of any pair of brackets determines the strength of the installation and this varies according to the size of the aerial, the length of the pole and the likely winds to be encountered. For small aerials in sheltered locations I`d separate the brackets by at least 1” for every foot of pole, but for large aerials in exposed areas I`d at least double it to 2” per foot of pole. Satellite dishes may require 3”, 4” or even 5” separation per foot of pole, depending on the size and likely winds.

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please help us increase the number of people reading it.


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Galvanising


Standard wall brackets


“T & K” brackets


Low profile brackets


Bracket spacing


Tilting brackets

Tilting bracket

The tilting bracket is specialised for, well, tilting. This product is very handy when you need to point your pole anything other than parallel with the wall (or whatever). This bracket is not intended for heavy duty applications (indeed it will only accept a 1 inch pole), but having said that it`s actually rather stronger than it looks !

The bracket will allow +/- 50deg (approx) of tilt from the perpendicular.


Note that there is an alternative to this bracket, an L Section loft kit, but insert the short of the L section into the side of the supplied two way bracket (see picture on the link). You can now rotate the pole to any angle +/-90 degrees.

It will be noted that if the short section of the L is inserted into the side of the two way surface bracket you can then rotate the longer section to any angle (also see tilting bracket).

Davis Vantage View weather station mouten on a 9ft Supercrank pole and 9x9in walll bracket.

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One problem you occasionally get with some weather stations is they have a mounting socket which will only accept a particular size pole, so, what do you do if you want to fit the station on the end of a pole of larger diameter ?  You can use a mast clamp to attach a short section of smaller diameter pole on the end but that looks a bit Heath Robinson (remember him.....), so an alternative is to fit a short section of the smaller diameter pole inside the larger one using suitable sleeving if necessary. Obviously the longer the overlap between the two sections of pole the stronger and more stable the joint will be. Lastly put a small bolt through the joint to stop the poles slipping.


External / internal diameters of poles.

Sleeving : this packing is simply cut from a spare section of the pole, but any material is suitable, even (for a small gap) insulation tape !

Pole / Mast Caps


Pole caps are plastic caps (or bungs) placed over (or inside) the ends of aerial masts.

Their primary purpose is to prevent wind noise, though I have to say that worrying about the wind noise you`d get from the pole, when there`s an aerial mounted on the end of it, is like the captain of the Titanic worrying how much it`ll cost to clean his uniform when it gets soaked as the freezing North Atlantic water creeps inexorably up his ship...... Actually, it must be said, under certain conditions, you can get a low whistle created when wind blows across the end of a pole, but it`s fairly rare and not usually that loud either.

You could argue that steel poles benefit from mast caps, because they tend to start rusting from the inside first, and the cap helps to prevent the ingress of water, though they also prevent it drying out as well, so it may be worth (just) fitting one to the top of the pole because the last time I checked water flowed down hill. Since all other things being equal we don`t usually recommend steel masts this is all a bit irrelevant because alloy poles (which we do advocate) don`t actually rust.

If you feel you want to use a mast cap I`d advise adding one made of decent quality insulation tape because it`ll last longer as there`s less danger of it splitting and falling off. Place a number of strips radially across the end of the pole, then run a length (stretched) round the outside of the pole to cover and strengthen them.

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Seam welded v extruded alloy poles


I had heard that extruded alloy poles were weaker than seam welded ones but because we only ever stocked seam welded I never gave it much thought. I was told this disparity was due to extruded alloy having a bit of air in it which would also explain why it isn`t as dense as seam welded, maybe someone out there can enlighten us whether this is true ! ? ! However, in May 2013 a mill which supplied most of the seam welded poles to the aerial industry went bust and suddenly there was a major shortage of welded aluminium poles and most of my suppliers were now offering extruded. Well, I thought, I suppose I`ll have to test them, which I did.


The first lot were T4 extruded alloy which is actually meant to be soft so its easier to crank. It certainly is easier to deform, it was so weak I could bend the standard 6ft x 1.25in x 16G pole over my knee. On test it failed with only 5Kg on it. Shite.


Next came the harder T6 extruded alloy, now this was much better, it failed at 20Kg.


Last I rechecked the seam welded which I tested a few years ago, the result was exactly the same, which was somewhat of a relief I can tell you. Anyway, it took 25Kg to fail which is 25% stronger than T6 extruded alloy.


I also checked 10ft x 2in x 16G poles and found the the T6 extruded poles to also be around 20% weaker than welded.

QED.

We only stock seam welded alloy poles…..

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Seam welded v extruded alloy poles on test

Use Of Longer Poles


Theoretically the higher an aerial is mounted the more signal it will receive. It is certainly the case that if any additional height is used to give adequate clearance (preferably by at least 3ft) to an obstruction in the path to the transmitter (e.g. a roof) the additional wind loading and larger bracket(s) required are very worthwhile. However in most cases (assuming the aerial is mounted at “normal” installation height, say 25ft from the ground) unless there is an obvious barrier to the transmission path I have my doubts about just how much extra signal you would get from (say) using a 10ft pole rather than a 6ft. Remember we`re talking the difference in the total aerial height, e.g. from 25ft to 29ft. Obviously if you live in a dip and your reception path is only just clearing the hillside, or indeed is through it, then any extra height may be significant, but generally speaking I wouldn`t expect miracles. Quite apart from anything else reception sites vary from sea level to 1000ft (or more) so how is four foot going to make that much difference ! Having said all of the above, particularly if the aerial is mounted relatively low to the ground (e.g.on a bungalow), and you`ve tried everything else, then a longer pole is always worth a punt !

In April 2008 we did some aerial height experiments to see on just how much extra signal one gets from an aerial 3ft 3in higher (the extra height from a 10 ft pole over a 6ft) and these more or less backed up the advice previously given above.

On a related point if you are suffering from signal problems then moving the aerial laterally may well be more effective than using a higher pole.

Importance of pole height

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2 inch pole coupler

The best method of joining two poles (although they must both have a 2" diameter) is the 2" Pole Coupler, shown right. Apart from looking a lot neater than two 2" x 2" clamps, it had also has the advantage that you don`t "lose" the height of the pole that is required for the overlap between the two aforementioned clamps. It is sufficiently strong that the pole would fail before the coupler.

Note !  We do not normally advise joining two 10ft x 16G poles together. If making up a longer mast we recommend coupling our 10ft x 2” (16G/1.6mm) to our 8ft “satellite pole” (which is 14G/2mm) using a thicker pole at the bottom and the thinner pole at the top. Think Eiffel Tower (stronger at the bottom......).

#CrankedPoles Using of a 9ft supercrank pole to place the aerial over the roof

Low profile brackets look very neat and if standoff is required this can be achieved by using a cranked pole.

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A  2”x 2” clamp is shown above left clamping two 2" poles in parallel (though it`ll actually clamp any 2 poles between 1" to 2"). Note that two are usually required to join two poles together in parallel. The clamp will also clamp perpendicularly, though only a 1.25” to a 2” in that plane.


The 2”x 1 clamp (above right) is holding a 2 inch pole perpendicularly to a 1 inch. It will also clamp 2 x 1" or 2 x 1.25” poles together, but it will only clamp perpendicularly, not parallel.

2 x 1 and 2 x 2 clamps

Think about it, the latter is capable of clamping something as small as one inch to something as big as three and a half inches. Obviously it will only clamp parallel ( ! ) and you`d generally use as a pair. Like they say on the cereal packets the pictures are serving suggestions, the clamps can be used in any number of ways, for instance with or without the centre nuts. Also, if clamping to a square section member, 2 saddles interlaced and “back to back” provide a flat surface, though if using the M10 bar the holes may need drilling/filing out to enable the saddles to remain perpendicular to the studding.

The 2.5” x 2.5” version clamps poles from 1” up to 2.5” (actually 62mm).

The saddles, rod and nuts/washers are all available separately.

3.5in clamp kit, clamps poles even bigger than 3in !

Lastly we have two clamp kits. The 3.5 x 3.5 version clamps two poles from 1” up to 3.5”.

2.5in x 2.5in heavy duty clamp kit The neastest way to install a pole on a fence post

Ever wondered what the neatest strongest way is to install a pole on a post ? You haven`t ? Well there`s one born every minute, so they tell me, but for the rest of you, the answer is to use some 2.5” saddles and some studding, preferably stainless studding (like this). You`d usually use two sets of saddles and get a  very strong but also very neat installation. The picture on the right is a 2” pole bolted to a 4x4 fence post. (Link)

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Thick steel takes years to rust through, but it does, eventually......

The next category up (in terms of strength) is the welded bracket. These are significantly stronger than the pressed variety and are welded together out of steel angle/bar of typical thickness 3.0 to 5.5mm. Welded brackets are available in either painted or galvanised finish. Although there is no difference strength wise between them the difference in finish is chalk and cheese. A painted bracket can start rusting almost straight away and will often show significant surface rust within a few years. It must be admitted that it`d usually take decades for rust to significantly weaken a painted welded bracket, but it will do so eventually, see picture on the left !


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The Vs would usually start rusting 2 to 5 years after installation dependent on the local conditions. It must be admitted it`d take 10X that length of time for a V bolt to rust sufficiently to significantly affect its strength but removing the nuts would be impossible rather sooner than that ! The reason the Vs are the first thing to rust is because virtually all V bolts are (only) zinc plated. It`s not possible to hot dip galvanise a thread, for obvious reasons*. The only way round this is are stainless V bolts, they don`t rust but are obviously significantly more expensive !


* OK, for those it isn`t obvious to, the threads would fill with galvanising and the nut wouldn`t screw up. You can get round this using oversize nuts but how complicated do you want to make it ? Anyway, stainless are superior to (even) galvanised.

It should be noted that the first thing to start rusting on a decent quality install (an alloy [or hot dipped galvanised] pole and a galvanised bracket) would be the V bolts.

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See Zinc plating v stainless corrosion resistance tests