Any VEE Beam design info around ?
 

See Jim Pennino's response to Inverted "V" posting below.

Tam/WB2TT
"DOUGLAS SNOWDEN" wrote in message
...
I am looking for something on the web that describes the optimum
angles between wires, etc. I am not talking about inveted dipole
beams, but a pair of horizontal wires (or sloping wires) that are at
a 30 degree or so angle, usually fed with open wire line.

Thanks

Doug N4IJ

Hi Doug

ie like half a rhombic?

I remember the ARRL antenna book has a graph of wire wavelength vs gain/lobe
performance. Cant imagine it being to much more difficult than that.

Possibly a websearch on rhombics? Might cover the development/theory.

http://www.mindspring.com/~cummings7/rhombic.html has a link at the end to a
Windoze pgm that calculates best wire angles... I didnt try it...

Cheers Bob VK2YQA

I am looking for something on the web that describes the optimum
angles between wires, etc. I am not talking about inveted dipole
beams, but a pair of horizontal wires (or sloping wires) that are at
a 30 degree or so angle, usually fed with open wire line.

Thanks

Doug N4IJ

"DOUGLAS SNOWDEN" wrote in message ...
I am looking for something on the web that describes the optimum
angles between wires, etc. I am not talking about inveted dipole
beams, but a pair of horizontal wires (or sloping wires) that are at
a 30 degree or so angle, usually fed with open wire line.

Thanks

Doug N4IJ

Depends on the length of the wires. Usually ranges from about 70-75
degrees for a V beam 2 waves long, down to about 28 degrees or so for
a 12 wave long V beam.
A V beam 8 waves long would be best around 30-35 degrees or so. There
is info on V beams both in the ARRL ant handbooks, and also the Bill
Orr radio handbook has a section. Dunno about the web...MK

Interesting design on the last page of ARRL's Wire Antenna Classics. It's a
coax fed monobander, made according to formula with 90 degrees between legs
that are 1.25 WL long. As I recall, the feedpoint impedence is 100 ohms, so
the designer connected a second vee in parallel back-to-back to get a 50 ohm
feedpoint. One support mast 0.25 WL high. The elements end near ground
level. By use of a single dpdt relay at the feedpoint the beam can be
steered 90 degrees. It's bidirectional, so f/s is good but f/b is zero. I
believe the designer described it as an "inside out rhombic."

It would be interesting to hear from anyone who has direct experience with
this design.

Tom, N3IJ

"DOUGLAS SNOWDEN" wrote in message
...
I am looking for something on the web that describes the optimum
angles between wires, etc. I am not talking about inveted dipole
beams, but a pair of horizontal wires (or sloping wires) that are at
a 30 degree or so angle, usually fed with open wire line.

Thanks

Doug N4IJ

I was thinking of something like a sloping vee beam. One mast and the wires
sloping towards the ground and supported a short distance off the ground.
Maybe three wires with one common that is switched between one of two outer
wires to change directions. It would be bidirectional and cover most of the
earth. I have antenna books stored that have this sort of info, just can't
get to them right now. I know it is in the ARRL antenna handbook, especially
the older one.

Doug

N4IJ


"Tom Coates" wrote in message
...
Interesting design on the last page of ARRL's Wire Antenna Classics. It's
a
coax fed monobander, made according to formula with 90 degrees between
legs
that are 1.25 WL long. As I recall, the feedpoint impedence is 100 ohms,
so
the designer connected a second vee in parallel back-to-back to get a 50
ohm
feedpoint. One support mast 0.25 WL high. The elements end near ground
level. By use of a single dpdt relay at the feedpoint the beam can be
steered 90 degrees. It's bidirectional, so f/s is good but f/b is zero. I
believe the designer described it as an "inside out rhombic."

It would be interesting to hear from anyone who has direct experience with
this design.

Tom, N3IJ

"DOUGLAS SNOWDEN" wrote in message
...
I am looking for something on the web that describes the optimum
angles between wires, etc. I am not talking about inveted dipole
beams, but a pair of horizontal wires (or sloping wires) that are at
a 30 degree or so angle, usually fed with open wire line.

Thanks

Doug N4IJ