Monday, 13 January 2014

My mast is up, finally.

After much procrastination, my mast is up and I have a wire HF antenna, pending more elaborate VHF/UHF antenna.

When I say "mast" I mean mast, it is the lower part of a big yacht mast. All aluminium and only weighs about 80 kg. It is self-supporting but has guys for more stability.

The mast tilts toward the camera position with an elaborate hand-driven pair of linear actuators. Using only half the mast (the other piece bolts on the top), makes for easy lifting. It can be left 2/3 down if needed, so it is not an obstacle on the ground and so I don't hit my head on it!
As you can see, "Ace" is not a mini-zebra, per first photo, and is kindly killing the weeds in the second. He is primarily, a Queensland Cattle dog or Blue Heeler, and yes, they are meant to have long tails for my American readers! The shadow in the shadow is "Jet" as in black, our whippet, also in a compromised position.
The tilting device was made at great expense (by someone else) to lift the sample cores on a marine soil-testing rig in PNG, for marine structures, like jetties etc. As such, it is only performing a fraction of its former capabilities. I just saw it in the local Gumtree classifieds.
Some of the guys are secured to steel "Y" posts driven deeply into the ground with a home-made adaptor for a Kango jack-hammer ; much easier than a sledge hammer; "like slicing butter with a hot knife". I have a second one for driving grounding rods.  The Gold Coast Amateur Radio Society, GCARS, has videos most Wednesday nights. Mark managed to find a collection of YouTube videos on grounding antenna masts and towers, which included a specialised jack-hammer device for installing grounding rods; so I just had to have one... (they are available on eBay for the 30 mm jack hammers, but not the smaller Kango). Jack hammers are pretty essential tools when renovating houses around Brisbane because of the shale and rock. I bought mine second-hand twenty years ago and still get good use out of it. (The shirt is very over-size, not that I am exactly slim).
The antenna, just visible in the first photo is a Alpha Delta Single Wire Multi-Band Dipole Antennas DX-EE, 40m and above. It has a very steep inverted "V" (limited by the rope that came with it). A RigExpert AA-600 antenna analyser, used by a non-expert, indicates it needs considerable attention.
I will try to do a post on the RigExpert analyser when I know a bit more about it, but they are very neat devices.
My other HF antenna, a very old Hy-Gain 18AVT all-band vertical, can be seen leaning inside the timber screen in the first photo. The coax connector corroded away. I was looking at a new antenna, but they are expensive in Australia, about $600. I have learned a lot trying to fix the old one. It needs a new bottom loading coil, but the traps and 80m coil seem ok. (Yes, two of the traps are upside down). I will do a bit little more to see if it is repairable.
I want two HF antenna to play with phasing, noise-cancelling. I might try a RX only long wire.


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