RadioBanter - View Single Post - Sources for Inexpensive RG-8??

April 8th 04, 07:00 PM

(Brian Kelly) wrote in message . com...
Cecil Moore wrote in message ...

Brian Kelly wrote:
. . . OK but 110 feet of feedline to an antenna at 40 feet is a whole
lot of feedline to deal with under normal installation condx. At least
around here in suburbia.

Hey, but not for field day. Whoever heard of a "field" with no room for
110 feet of feedline?

All depends on the situation. Last thing ya need on FD is more
complications.
Which is why I've gone with coax-fed dipoles on FD for years.

The books give all sorts of figures for "open wire line". But many of
them are for the classic lines made of #14 copper spaced 4 to 6 inches
with ceramic spreaders every few feet. Brown poly TV twin lead with
rectangular holes punched in it is a whole 'nother ball game.
'Specially at high SWRs and when it's wet. Which may not be a
consideration in NTX but is a big consideration in EPA.

Well . . it sorta "depends". In the instant case the FD "field" is one
of my daughters' 1/4 acre back yard, three decent-size hardwoods
spread out in maybe a 120 foot straight line and that's it. The other
op will probably be N2EY and he isn't into deep bush ops either.

I'll do deep bush ops anytime the opportunity presents itself. But
this isn't one of those times.

IF one can figure out to what to do with all
the excess feedline without messing it up.

It can be coiled into a big helix as long as the adjacent coils are
a couple of feet apart. You can run an insulated rope to the antenna
feedpoint and coil the ladder-line on the rope with the coils tiewrapped
a couple of feet apart.

That's slick.

Until the rain falls or the wind blows or somebody walks into it in
the dark.

Biggest headache, though, is switching the various lengths for
different bands.

At the least you would have a conversation piece
to discuss over 807s (the best part of field day. :-) A photo of it would
probably make it into QST since it looks somewhat like a slinky. ;-)

I was thinking more along the lines of sniping one of the orange
barrels which are the Pennsylvania State Flower. They're quite readily
available at construction sites along the PA Turnpike and
slinky-wrapping feedline around one of those should do the job.

Would solve the walking-into-it problem too.

Let's see here, 2.5 feet diameter times Pi . . 7.85398 feet per wrap .
. yeah, that would get rid of most of the ladderline. At worst maybe
I'd need a couple of 'em in series.

QRX for the QST cover shot.

If it were me, (which it ain't) I'd either go with a coax fed parallel
or trapper.

Or build a nice split-coil balanced tuner and run the ladder line
right to the tuner. Real ladder line, or at worst that "fretline"
stuff (which I have squirreled away). Lessee, I got the splitstator
cap, and some nice coil forms, and a smaller cap for the link. Oh
yeah, some real all-copper alligator clips for the taps....

Or do it AG6K style.

--

The big question for any FD antenna is "how many QSOs"? All the
simulations and Smith charts don't count for any points - QSOs do. My
personal best is 629 QSOs with one 100W rig, one op, one mode, three
bands and two antennas. Coax fed trapper set up as inverted V for
80/40, quarter wave groundplane elevated 5 feet with 8 sloping radials
for 20.

Anybody here beat that on FD with only dipoles and verticals?

73 de Jim, N2EY