HOME BREW 6M HALO

Mast Fabrication

W3DHJ   >>   6M Halo   >>   Mast Fabrication

I played around with lots of ideas for doing the Mast-to-Mount assembly. None of'em really tickled my fancy. Then, one day, I was scrounging (what else?) around in the local thrift shop (where else?), and I spotted a pair of aluminum crutches.

To paraphrase President John F. Kennedy:
Bingo!!


What I wanted all along was a Mast-to-Mount assembly that I could take down easily in the dark, with the wind howling, during a rainstorm, and with a full bladder. So a quick-disconnect was a necessity. Here were a pair of quick-disconnects! Working those detent buttons will allow that lower center tube to pull completely out of its upper, mating tube. Furthermore, you gotta believe the manufacturer's liability insurance requires that the crutches support the average drunken 300 lb. man with a broken leg. So, sturdy it is, too!

The dent buttons on these crutches are just the ticket for easy put-up and take-down.
The outer tube is 1" O.D. A Nice, Standard Size. Perfect!
$2.00!! Yes!, two buck -- the pair - at The Goodwill Store.


After disassembly of the crutches (and saving the leftovers for Future Projects), this is what I had to work with. Great! The two crutch tubes (with the detent buttons) will be slipped into, and clamped at, both ends of a center, 37" long, 1" diameter aluminum mast section. The bottom of the completed mast will slip and lock into a pipe that pierces, and is welded to, the antenna base mount. The top of the completed mast will slip and lock into a mast stub that the halo is affixed to. This mast "stub" just happens to be one of the 1" O.D. crutch sections with the already-existing holes for the detent buttons.

Looking more closely at the lower mast mount, you see a receiving tube that protrudes 5" above, and 3.5" below the mounting plate. This is cut from a piece of stainless steel tubing that I had in my Scrap Pipe Barrel (where else?)

The tube is welded on the underneath side of the mount. About 1" up from the bottom of the stainless steel tube, I drilled the detent buttons' receiving holes. The top of the stainless steel tube is immediately below the worm screw clamp. The worm screw clamp is at the bottom of the 37" section of 1" aluminum tubing and is clamping the mast tube onto the crutch section that has the detent buttons. Thus, squeezing the detent buttons at the bottom of the stainless steel tube permit the mast to pull completely up out of the mount.

Those black 'things' you see are double-sided Velcro straps that I use to 'dress' the coax cable up the mast to the halo.

Here's another view of the mast mount with the crutch section about to be inserted. (Of course, one needs to squeeze the detent buttons to get the mast started down into the base section.)

You can see the holes at the bottom of the receiving pipe. This is the location of the detent buttons for highway driving. The upper button holes can be used when parked -- to gain a wee bit of height over the vehicle.

Here, maybe, you can better see how the crutch pieces fit into the design. The tube from the crutch -- that had the rubber foot -- is clamped inside the 37" mast section such that it extends (with the detent buttons) up into its mating crutch section with the locking holes. Here, the "mating crutch section" becomes a 'stub' of a mast -- bolted to the halo-to-mast block. (More about all this further down the page(s).) I use 'full insertion' here and at the base for maximum sturdiness at 75 (85) MPH.

Here, too, the mast buttons are pushed up to the last set of holes for highway driving. When parked, I could use the lowest set of locking holes.

Also here, you can see:

- the worm screw clamp on the 37" mast section which holds the inner crutch tube (with the buttons up.)

- a Velcro strap holding the coax in-place.

- a "Pull Back Arrestor" string (that'll be discussed further down the page(s).)

So, at the bottom of the mast, it's much the same -- just upside down. And, the stainless steel tube (with its two drilled holes for the buttons) substitutes for the outer tube section of the crutch.

Here you see me about to insert the mast (right hand) into the mast stub (left hand) that the halo is affixed to. This is done first -- then the mast and halo are inserted into the vehicle mount.

(For those of you that have never met me, now you have my picture... Well .... as of 2002)

When it's all put up -- with the mount 2' off the ground -- with the mast built as described -- and using the detent button holes for highway speeds: the halo is 79" off the ground. Whoopee!, you say? Well, I had (uncharacteristically) planned ahead for the time(s) when I would forget and pull into my garage without remembering the halo was up.


Ok, it's taken a lot to get this far. And, you've shown incredible patience.
However, I think I've pretty well explained The Mast.
Next, we move on to "Halo Fabrication":

---

      6M Halo - Initial Halo Fabrication

      W3DHJ 6M Halo - Front Page

      W3DHJ Home Page

Constructive comments and/or discussions:

Last updated: 06-Sep-17 -- Now "Mobile Friendly"