Monday, July 18, 2011


(I couldn't resist the title).

What's a "LineDragon?" It's a way of supporting vertical feeders for a balanced transmission line and getting them around the roof overhang and gutters. Sunday, I designed and installed the Mk. III:Mark I was a simple section of unpainted 1/2" plywood screwed to one of the joists (or are they rafters?). It worked but it was off-center to the natural drape of the line. A season's worth of weather left it with a permanent skew and wanting to delaminate. Mark II was the center section of the present edition and a 2x4 spacer, but even it wasn't close enough to where it needed to be, so I got out the good miter saw and a drawing pad and ended up with what you see. Short 2x4s screwed to the joists support transverse pieces that in turn hold two more short sections that support the upright, this time in line with the straight-line path between the feedpoint of my G5RV double-Zepp antenna and the feed-through insulators that bring it into my basement ham shack.

The vertical portion, with its "mouth" holding one of the spreader insulators,* bears a resemblance to the prow of a Viking ship and thus, the LineDragon!

More details: You can clearly see the insulator being "chomped." It is held in place by the tension on the feedline leading on up to the center of my antenna (there's another little cheat up the way, a kind of X-brace that carries it clear of the peak of the roof).

Here's the view from below. I installed the 2x4s on the joists first, tacked the transverse pieces in place, then found the proper position for the support assembly by trial and error, clamped it to the transverse pieces and removed it as an assembly to install the fasteners holding that subassembly together. The way, I did the bare minimum of trying to hold parts in place overhead with one hand while driving screws with the other. Even cheating with a battery drill, that's way too much effort!

All done in a mad rush to get it installed before my house-painter returns on Tuesday. I'm probably going to be shooing birds out of it next Spring.

Feel free to borrow and adapt the idea behind this gadget, if it's something you could use.
* Simply short lengths of semi-rigid irrigation tubing, with holes drilled to clear the wire and narrow "V" cuts so you can snap it in. This clever idea -- and the all-one-wire antenna and feedline -- was invented, developed and sold by the late Gary Gomph, W7FG; his antennas and line live on at True Ladder Line, as does his callsign at the Gomph Memorial Radio Club. (Another memorial page at this link). W7FG also founded Vintage Manuals, Inc. He'd sold it a few years before his untimely passing and it's still around.


  1. I *thought* that was Gary's ladder line! It has a distinctive look to it.
    Works great, too!
    Very sorry to hear he's SK. I bought many manuals, and a bunch of the ladder line, from him.

  2. Rafter. Joist is for floors.

  3. North said...
    Rafter. Joist is for floors.

    ...and ceilings. Horizontal is joist, angled is rafter.

  4. farmist: Dad always said if you walk on it, it is a joist, if you look up at it then it is a rafter. Master carpenter for decades. Likely a regional terminology difference, though.

  5. If you're in an (unfinished) attic and you don't walk on the joists, bad things happen!

  6. For most people it is not a mistake you make twice...