" Stephen Cowell" wrote in message
. com...

"Jimmy" wrote in message
. com...
In the plan I have for one it calls for a piece of fiberglass rod,
others
bakelite. to keep the two sections of the J at the right sepration.

Are we talking regular J, or Super J here? The
antenna you're describing is a Super, a colinear
array with the middle phasing section. In a normal
J-pole, there is no insulator needed.

If a 2 meter J-pole construction is imperfect enough that
the short and long vertical portions are not exactly parallel
it might require an insulated piece of something to force them
to be parallel. If one builds a 6 meter J-pole the long and short
vertical parts are sufficiently lengthy and flexible that some
kind of insulating brace will probably be required to keep
winds from misaligning them. I recently built just such a 6 meter
J-pole that used a 102" whip to reduce weight and wind loading
on the top of the 1/2 wave radiator side. Even so the original plan
called for a pvc brace to keep the vertical tubes aligned. ( the
whip portion of the 1/2 wave radiator started about 7 inches
above the top of the 1/4 wave matching stub) Both the lower
portion of the radiator and all of the matching stub were of
3/4 inch copper pipe.

Harold
KD5SAK