"Richard Harrison" wrote in message
...
Jim Richardson wrote:
"Could you build a colinear of a single long line bending it back at 90
deg. every half wave---?"

See the "Super J" in the "ARRL Antenna Book", page 16-25 in my 19th
edition. That is more or less how it is made. The two 1/2-waves,
in-phase, are end-driven with phase inversion provided by a
short-circuited 1/4-wave stub between them.

At frequencies higher than 2-meters, this would work for more than (2)
1/2-wave sections. The practical limitation is mechanical.

Best regards, Richard Harrison, KB5WZI


Hi Richard

About 45 years ago, I designed a vertical collinear array of dipoles for
1.7 GHz (actually 1,700 Megacycles then). That antenna was a series 1/2
wave sleaves located below a coaxial dipole. The nice aspect was the
simplicty of its feed. The "beam squint got fairly great since there were
alot of passively excited 1/2 wave elements
I had capability of measuring the radiation patterns from the antenna, so
I can assure that the concept you propose will work.

Jerry