On Wed, 14 Apr 2004 17:33:42 GMT, zeno wrote:
I just happen to have a bunch of that black poly 1/2" irrigation tubing,
which cuts up easily, and is apparently a good choice for diy ladder line
because of its UV tolerance.

Hi Bill,

Black is usually indicative of carbon content; but I wouldn't let that
stop me the first time around if it was handy (pop it into the
microwave and nuke it to see if it gets hot - this is not about
microwave frequencies, merely tendency to conduct and to dissipate).

There is no foil-backed insulation to worry about coming into the house
peak or ceiling. I have a bucket of those old porcelin knob&tube feed
thru dealies out in the barn.

Sounds like a done deal.

I am making some masts out of whatever I can recycle, mostly old metal tv
telescoping masts. I will have to guy them if I get them up as high as I
possibly can for the four corners of the loop. I was thinking of using
pulleys and dacron for the guys, pulleys so I can redo the guys after
years...and they look like they are about to fall apart etc. without
having to take down the poles.....or should I use wire for guys? The
masts are metal anyway, maybe wire guys are ok, what do you think?

Dacron, I think, is the more long-lived, goferit. Use wire, don't use
wire; it won't matter much.

As for measuring stubs. Not sure how that appeared as a concern, but
as to measuring in general, attach a known mismatch at the far end and
measure the SWR across frequency. If the readings look better than
you would have reckoned, then you have something wrong along the way
(loss tends to sweeten the appearance of problems). The known
mismatch could be as simple as a direct short at even multiple of
quarterwaves away (or open on odds - whichever). Make sure to account
for velocity factor, or simply compare the physical length to the
measured electrical length of the short/open. This, too, will give
you an indication of line health. You can go farther and calculate
the actual line Z, but who cares? Only guys like me (and that hardly
counts for much).

73's
Richard Clark, KB7QHC