I’ve got a mast!

To be honest I’ve been so busy chasing QSO’s all over Europe and Eastern Europe the past few months I’ve been neglecting my pile of projects and housekeeping, so now that the weather is good it seemed like a good time to do something about getting my 30 meter 1/4 wave counterpoise antenna off of the top of the rotten fence post in the middle of my back garden and up onto something more becoming!

Back in March I started hatching a plan based on the advice of Mike (G0JMI) from Alton Antenna Arrays. Mike suggested trying http://www.aluminiumwarehouse.co.uk/ as a source of cheap aluminium tubes to build a sectional mast. The original plan was to use a 2.5m length of 40mm diameter 16swg tube and a 2.5m length of 44mm diameter 16swg slotted inside each other to give the overall 5m height. The 44mm section is fixed in position by driving a circular stake into the ground and slotting the aluminium over the stake.

It’s a very neat and cheap solution compared to the prices you pay for bespoke masts from radio suppliers! The only snag I had was the absence of any decent lawn or earth at the point I wanted to site the mast to anchor it. The joys of concrete! I looked at trying all sorts of anchoring solutions until I had the inevitable Gru “Lightbulb!” moment. (If that just passed over your head, watch Despicable Me and all will become clear). I’d got a perfectly good fence post set in a Metpost socket anchored in God knows how much concrete at the far corner of the garden behind the shed. There was potentially enough of the wood available to attach a square section tube to it.

I decided on a 5m 1.5″ x 1.5″ x 16swg tube costing a whole £16. The pisser was then having to pay the same again for delivery but you can’t have everything! A quick rummage around eBay provided a nice end cap to keep things dry inside, a few dog bone insulators and 100ft of Paracord. The local builders merchant came up with a cleat hook, eye bolt and some M6 coach screws.

Yesterday I nearly wet myself at the sight of a courier carrying the largest loo roll innard known to man up the drive. I was expecting a strip of aluminium not this thing!

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Ironically it took more effort chopping the cardboard tube up to get it in the bin than putting the mast up.

Now naively, 5 meters doesn’t sound much inside my head, but when I held the tube up against the house it all came into perspective. Perhaps a shorter one would have done?

Now the whole idea of having a hobby is not to hack your neighbours off with it. Never has that been more true with amateur radio! There are huge great sections in the exam syllabus for the radio exams about EMC and interference and alongside that there’s the professionalism of the sport, which says wherever possible don’t go sticking a thing that looks like a 5 meter light sabre in your garden for fear of causing a bit of neighbourly angst! To coin a phrase “With great erections, comes comes great responsibility”. (I’m sure someone can correct that misquote for me!)

Liberal application of a hacksaw reduced the height to an item akin to a high level washing line, which is not an uncommon sight in the back gardens of the numerous back to back terrace runs in the local area.

Now the next hurdle to overcome was anchoring this thing down in a safe and secure manner. I genuinely didn’t want it to come crashing down in a storm on my neighbours let alone anyone else’s property!

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The weapon of choice to overcome this hurdle was a coach screw, more than one to be honest. Anchoring it in both horizontal planes meant it was going nowhere! Seriously, this thing is solid which is very reassuring.

Strangely, when I did my exam one thing that stuck in my head working through the Advance! course material was the paragraph about rusty bolt rectification. I don’t know why it stuck in my noodle, but it did because I then got a question on it in my exam, which was a banker! Then, last month RadCom had an in depth article on metallurgy including corrosion, rusty bolt rectification again! Now with all that in mind, preventing galvanic corrosion between the aluminium mast, steel fixings and so forth was top of my list. A top tip from my man at CP Fastenings was to heat shrink everything and place either nylon washers or insulating tape between surface unions. Worth the 5 minutes to do it, as in the salty atmosphere of the south coast of England, things corrode quite nicely with little encouragement!

So with all that in place and a few holes drilled we were off. Now typically, none of the other bits I had ordered had arrived so overnight a temporary lashup was made which could be easily undone when all the final pieces were to hand. Despite the 16mph gusts of yesterday the temporary fitting hadn’t budged! Again, reassuring.

Today, everything else was waiting for me on the door mat when I got home. So in no less than 15 minutes, everything was in place and the 30 meter counterpoise antenna was fixed to it’s new home, looking no more imposing than a washing line. I’m more than happy as I now have the ability to experiment further. My trusty 728HFA limited space antenna is hidden beneath the eaves of the house and works a treat, but admittedly being able to swing it through 90 degrees and run it away from the house and all the electrical noise it contains would be an interesting experiment. That’s for another day.

In the meantime, I can enjoy the rest of the summer sunshine / pouring rain beneath my new washing line.

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