Bank Holiday Monday - Mast preparation :)

After my last post on 6M I got to thinking about how I could get a better antenna for 6M, and perhaps 4M and then there's always 2M as well isn't there !

I've had in my mind for several months the idea of a 'temporary' mast to enable me to quickly get some decent (perhaps 6 element 6M beam) up in the garden for weekends and contests.

The basic criteria would be -

1 - Temporary - most important after studying the planning regulations, I didn't want to apply for permission for a mast, especially as I live in a conservation village, whilst I might find antenna's pretty special others (including the xyl) might have other ideas. A 'temporary structure' is defined as one that is not permanently fixed to a building - or other structure.

2 - It must be fast to put up and take down - I want to do radio not build masts etc.!

3 - Would be high enough to get above the house from the back garden

4 - Would be able to be assembled as dis-assembled  by one person (me!)

5 -  Would have minimal impact when taken down (ie must be temporary, not visible and not a structure when taken apart)

I've been thinking about it for some time and in the end decided that an ex mod pump up mast would be best.

Not a SCAM12 - those are massive, and whilst built like the proverbial 'brick out house' they weigh a ton and are designed for a small army to assemble, so what next ?

Then I came across (again via eBay what would I do without it) a Hilomast NK9, a lot more manageable - when pumped up 9M, 2.3M when retracted, 22Kg's of head weight and it weighs approx 21KG, which whilst bulky is manageable for a lard ass like me :)

It was advertised as "possibly in need or refurbishment"  I took a punt and won it just over £100, with semi local collection, I picked it up in my 7 series - couldn't do that with a SCAM12 :)

This was autumn of last year, I got a seal pack from SMC Communications (£70+ ouch!), and then did nothing with it.

Then my 6M post |(and an upcoming 2M low power contest), and I thought I take a closer look at how I could use it.

Well after 6 hours or work, I've replaced all the seals, and now know intimately the inner

The construction of a Hilomast
(c) Hilomast (SMC)

workings of the Hilomast !! - if you've any questions just ask !

I'm was very impressed with the build quality, really good stuff, great to work on, perhaps the equivalent of a BMW or Audi in engineering terms, when I dismantled it, I discovered a hand written note on one of the upper tubes, that it was re-built in 1994, so I doubt that its been touched since then. The top section is slightly damaged, but has no effect on the use of the mast at all.

I did check before working on it and it didn't pump up at all :(  and now after working on it, it not only pumps up, but also stays up (without using the locking handles), so now all I've got to do is work out how to put together a ground mount to help me put it up, and also how guy it to make sure it doesn't fall over with the antenna's on top !!

I've already decided that the cables would be permanent from the house to ground level down the wall in a weather proof box. I've already go a method of getting cables from the loft to the outside world using the a waterproof hole in the soffit (or is it barge board) of the roof, with a removable, flying cable up the mast, including the rotator control cable, to enable quick set up, and keep things tidy.

I recon that I should be able to get it set up for weekend working (I'd have to choose the antenna obviously !) in about 45-60 minutes and then take it down in about the same.

That should give me great gives flexibility  (Contests are only at the weekend, and actually I'm only around then to play radios's), a reasonably good antenna for my favourite bands 6M,4M,2M, and no planning problems as its temporary, I can even drop it down to 7ft when I'm not using it to avoid neighbour problems.

I should be able to store the antenna vertically at the side of the house safely and so not too much disassembly should be needed, and if it does need this its a small price to pay I think.

So next step now I've got a working mast is to get the ground mount sorted out, and get the cables put in permanently. Thinking cap on, I've a few ideas already.

Sorry there's no pictures, I didn't really think until I was finished, that I'd write it up on the blog, silly me :( - I will when I do the ground mount, and of course the final result.

Now how big is a 40M three element beam (!!!) :)

73's

Chris