Poles, clamps & brackets

Eyup, may I share my queries with you wise folks please?  I'm relocating shack/antenna (from garage to house) and making a few small changes at the same time, would be good to get suggestions

Currently using a 5m steel (48mm) pole, Shelley clamped to a 5m alloy (41mm) pole with approx. 2 or 3 foot overlap.  So it's about 30 foot of mast and works great but does look a bit clunky.  This side-clamp arrangement fit well in the old location but not really the new one, where a single pole would be better.

Given the ID of the steel is 41.8 and the OD of the alloy is 41.27 maybe they can be telescoped 2 or 3 foot instead...  How would I lock them together - with a cross-cut (slit) on the steel and a heavy duty pipe clamp I guess.  Is this even a safe idea, or are Shelley's the best thing to stick with?  To be clear, they would be treated as 1 pipe afterwards, not fiddled up and down for kicks.

One other thing, I will be using 2 or 3 K brackets from just-below-gutter down, meaning the foot of the pole will be about 10 to 15 foot from the (physical) ground.  I have the opportunity to stand it on a flat roof at 10 foot or raise it a little higher, which would obvs put all the weight on to the brackets instead of the flat roof.

So the brackets need a reet good fixing - what's for the best with old housebricks, can anyone advise on the drill bit and bolts I should look at please?  That gives me the option for roof support or direct-to-wall, so would be good to know if there's a physics thing regarding pole with a fixed base vs pole in 'free air'.  Might not be worth worrying about, that one...

That's ALL for now chaps, but do tell me about other things I should also consider!

The antenna is an A99 at the moment and the only load on the mast.  It seems to be safe-as-houses at 30 odd foot un-guyed, having good sway from about 4m up the steel where the overlap starts.  I'm going up another 10 foot (raising mounts, not extending the pole) and hope it will still be as safe, but not sure if that flat roof would be best to support that bottom steel pole...

Huge thanks in advance

Hi Chris,

Personally I wouldn't suggest any sort of swage fitting or masthead clamping to any poles that weren't being supported above and below the join so think your overlapped Shelley joint would be the best. (Ugly is OK in my book if it's actually safe!)

We can often overthink these things but I think it's better to be over the top than risk a scaffold pole falling on your head, one of your loved ones, or an innocent member of the public. 

We often forget that it's the oscillations of such arrangements that cause the eventual failure and fall of such structures. You only have to think of how we pull a difficult nail from a piece of timber by moving it back and forth until it frees or breaks....similar thing.

With the length of poles you're suggesting to support I'd go for at least three K brackets if they are not going to be ground supported or at the very least two heavy duty brackets spaced well apart.  Think of how we use a yard broom or brush, with two spaced apart hands.

As for wall bolts I've always used expansive bolts for such fittings, plastic Rawl plug type affairs just won't do in this situation. If you have an older house the decent engineering bricks are up to the job but check for 'blown' bricks. On newer builds the brickwork is just a skin so always best to test first to make sure the brick won't blow or split with such a fitting.

Drill bit recommendations? That's always going to be a personal choice but if it helps any I've always used the Erbauer cobalt tips. I have a 1940's house with bricks as hard as granite and these bits have always cut through no problem. They come in SDS and standard types.

Remember to keep yourself safe if climbing ladders for such tasks and follow guidelines. You won't be in a position to blame someone else for your own safety if the worst should happen after a fall. Ladder safety is obviously a concern especially when you consider it's a tested subject for the Radio Amateur exam!

If you're unsure of anything, then get a professional antenna erector in. A reputable tradesman or company have the experience for such tasks.


If all that starts sounding a bit expensive then think about the following....

If a 'concerned' neighbour calls out the fire brigade fearing your antenna will fall - you will get the bill for it.
(Happened to a friend of mine!)

If another 'concerned' neighbour calls the local council about 'safety' concerns - you'll be up the proverbial creek without a paddle unless you can prove it is installed safely. Either way, it could cost you money.

If the antenna and poles falls cutting through the local BT phone lines - you'll get a huge bill!
(Happened to another radio acquaintance, cost him a fortune!)

If the antenna falls on a neighbours property they could very well sue you for damages. Sign of modern times on that one I'm afraid.
(Where there's a blame, there's a claim sort of nonsense.)


Sounds like a lot of "If's", we don't like to think about them and often we ignore them thinking it's a bit of a 'faff'.

The way I think about it is what if it all came crashing down on an innocent.....child?
(Your child, grandchild, neighbours child, doesn't matter who's child.)

Sends shivers down your spine doesn't it? Always guarantees me to get things done safely.


Anyway, my tuppence worth but you're bound to get the old, "Nah, sling it up mate", sort of thing. 
I'm amongst the fewer of the population that admires a well placed high 'twig', often accompanied by the thoughts of, "Phew! I'll bet that gets out!"

But not everyone else has the same thoughts.


Best of luck with it all.

Victor

Victor, you're a star mate, for my 2p got a very good deal out of you

I'm going to stick with the Shelley's so the join stays strong.  I'm happier with that, as I'm no engineer!  You're correct, I would use 2 K's if the pole is sitting on the flat roof, or use 3 K's if fully wall-mounted.

BTW my K's look very well made and arrived quickly from TekEir, where they sell individual K's without forcing an (unwanted) T on you.  The welding and galv. is excellent, and they were 32 Euro all-in for x2, delivered in 3 or 4 days from Ireland.

Yeah I will be using some metal-sleeved rawlbolts as you say.  The garage install was into block (not brick) and I used a different fixing (sleeve-less, like a huge self-tapper) but this time it's brick and I figured a new approach.  Maybe M10 with a 16mm hole but not sure about bolt length until I get a sample brick in hand and figure it out.  They are good old bricks, not the modern stuff.  I'll check out that drill bit - thanks Victor.

I've just read some advice about avoiding the house-corner-brick (which I was actually targetting lol) so am looking for a better spot to stick the drill in.  I'm staying above the flat-roof so I can stand on it to fit the brackets (me and ladders don't get on) and will let the weight of the pole sit on the flat, so the brackets are just keepers really.

Can't afford to get a Pro Installer - have already blown the budget on brackets and bolts - but will be sure to get good free advice upfront, and have one of my more competent (than me) mates on hand when I get stuck in.  Probably the one that owns he SDS drill lol.

Will update further with pictures etc. as we get there.  Thanks for not mentioning the elephantron in the room.  73's

LeedsChris wrote:

 and will let the weight of the pole sit on the flat, so the brackets are just keepers really.

Put something between the pole & the flat roof. As flat roofs are very prone to leaking & don't need any help in doing so.

Cheers Seasick, I hear you.  I'll look for some kind of 'plinth' to raise the pole 12" up from the flat to the lowest K.  A plinth that helps the flat roof remain intact, that sounds do-able, good call

No worries Chris.

Glad my tuppence was of some help, I'm a cheap date.

Honestly, if I've been of help then job's a good'un. It should really be the 'radio' way to help each other out as best we can.

Nice pointer on the corner brick, never thought to mention that, always best to be a brick or two in. Great job with the metal sleeved bolts too and checking them out first. Top man.

The TekEir brackets are damned good for the money and as you say they'll sell you what you want, not what they want(!) They do come highly recommended.


Well Chris, sounds like you've got everything in hand mate and just doing a double check which is great. "Measure twice, cut once" sort of thing, spot on.

Oh, before I forget. The Erbauer drill bits were a discovery after noticing them whilst queuing at the local ScrewFix a while back, so I gave them a shot and they cut through brick beautifully. Well worth it and surprisingly cheaper than other Cobalt tips.

Pictures will be great mate if you can. We can admire your handy work and it may well help out someone else looking to do an antenna install.


I wish you all the best with it, keep yourself safe.

73's

Strange how things turn out, innit?

I picked a good spot away from the flat roof so I could use 3 K's over a 2m spread. My SDS mate came round, goes up the ladder and fires into the top K no worries - he's about 5 seconds into the first brick when my Mrs decides she knows more than any of us about this antenna nonsense and gives us firm redirection. Her first choice was biologically impossible but we did reach agreement eventually...

So it was back to the 2 K plan on the corner plot over the flat roof. Less than perfect, but better than nowt. The brackets have taken a great hold, very solid,  and we placed them as best we could in the limited wall space available. The fixings are M10 75mm Rawlbolts, needing a 16mm drill. You could hang a car off them!

We only got a 1m spread through, so I am only using 1 x 5m alloy pole (41mm) rather than making up a 9m combo pole.

First attempt to erect the pre-joined pole/antenna went a bit scary/wrong when I 'lost' the weight of it and it started swinging around all over as I was dead-lifting it hand over hand up the the side of the extension onto the flat roof. Not the way to do it, trust me.

Second attempt I used my brain.  Set an 8 foot steel pole into the K's to use as a mounting rail, and attached 2 x swivel clamps so I could swing the pole/antenna up safely and clamp it into place. Same as you would do with a ground install really, but into K's.

I have since changed the swivel's over to Shelley's to lock it off properly. The scaffolding gear is very strong but not designed for long term install of parallel poles under side-load (swaying around in the wind). Have to say though, the swivel clamps are superb for the transition stage from ground to air! Never used them before and very impressed.

The pole-to-pole overlap is about 4 foot and starts right above the top bracket, extending above the gutter - meaning my 5m pole starts at 5m height and feedpoint will be around 32 foot above footpath level. That'll do me for now.

The best bit, is my Mrs actually came back in favour of plan #1 eventually. So I have 3 more K's and a 6m alloy scaff all ready to go, and waiting until I can stretch to an 827 to put up as well as this one.

73's

Nice one Chris, glad you've got all sorted out.  


Glad you got it all done without injury too only suffering a butt-clenching moment of 'whoops!' 
Guaranteed to stay in mind and be added to experience that one.

Our 'better halves' are often a great support to us even if it might not seem so at first. I wouldn't be without mine and she does put up with rather a lot.


Thanks for sharing your story and pictures on the forum. Most will appreciate the effort that goes into such installations and it may spur on or helpfully inform others contemplating a similar task.

Great work.


All the best,
Victor