Owen Duffy wrote:
On Thu, 05 Jan 2006 15:30:56 GMT, Cecil Moore wrote:


jawod wrote:


I will assume that balanced (air) feedline is homebrew. What
recommendations are there for spacing between the twin lines? Number of
spacers per foot? If homebrew, how to keep spacers from
migrating...will small wire "stays" modify feedline characteristics?

For all-HF-band operation with relatively high SWRs, the
spacing doesn't much matter. 2"-6" is a practical range.
Spacer spacing depends upon wind conditions. Two foot
spacing seems reasonable at my QTH. Some spacers pinch


Did you really mean two foot spacing. This imperial measurement system
can be a bit tricky sometimes.

50 cm, then




the insulation on the feedline and thus stay in place.
Very small tie wraps could also be used.

--

On Thu, 05 Jan 2006 19:48:55 -0500, Amos Keag
wrote:

Owen Duffy wrote:
On Thu, 05 Jan 2006 15:30:56 GMT, Cecil Moore wrote:


jawod wrote:


I will assume that balanced (air) feedline is homebrew. What
recommendations are there for spacing between the twin lines? Number of
spacers per foot? If homebrew, how to keep spacers from
migrating...will small wire "stays" modify feedline characteristics?

For all-HF-band operation with relatively high SWRs, the
spacing doesn't much matter. 2"-6" is a practical range.
Spacer spacing depends upon wind conditions. Two foot
spacing seems reasonable at my QTH. Some spacers pinch


Did you really mean two foot spacing. This imperial measurement system
can be a bit tricky sometimes.

50 cm, then

Well Amos, I misunderstood the two foot spacing to be wire spacing
rather than spacer spacing. Both spacings are discussed in the space
of one paragraph, and it is a little open to misinterpretation. I
thought he may have meant wire spacing and two inches rather than
feet... hence the reference to the measurement system. Cecil did clear
it up.

BTW, two foot is closer to 60cm (60.96cm).

Owen
--

Hello Jawod,

I have buit a twin leed for my center feeder dipole with PCV tubes:
http://www.barbaxoops.com/modules/xc...&album=7&pos=2

Tubes are after filled with glue. You can see here the final result (click
on the picture to enlarge it):
http://www.barbaxoops.com/modules/xc...&album=7&pos=4

Spacing is 5 cm
Distance between spacers is 60 cm

It has been installed for 3 years. It has resisted to many strong winds.

Good luck

Regards

Jean-Marc
F4DRH
www.barbaxoops.com







"jawod" a écrit dans le message de news:
...
I will assume that balanced (air) feedline is homebrew. What
recommendations are there for spacing between the twin lines? Number of
spacers per foot? If homebrew, how to keep spacers from migrating...will
small wire "stays" modify feedline characteristics?

This is all about feedline to simple dipole or inverted V.

Thanks,

a new (old) ham

jawod aka john

"jawod" wrote in message
...
I will assume that balanced (air) feedline is homebrew. What
recommendations are there for spacing between the twin lines? Number of
spacers per foot? If homebrew, how to keep spacers from
migrating...will small wire "stays" modify feedline characteristics?


I've heard some use well-varnished dowels as well as pvc pipe, and pieces of
scrap vinyl siding cut to size and drilled for spacers.
and for stays, I've heard epoxy, super-glue, and hot-melt glue works.

If the pieces of vinyl (siding scraps) were folded into a "V", then drilled
for the wire on each side, the springiness of the vinyl would probably hold
itself in place without glue.

spacing of spacers would depend on the stiffness of the wire. Use common
sense - just need to keep a consistent spacing. It would take more spacers
for flexible, stranded wire than for stiff solid wire. 10 guage solid wire
is stiffer than 20 guage braided stranded wire.