[old sparks]

Bouval;

Innovative construction idea!

Generally, steel is not the best choice for antennas, especially ferromagnetic steel. I have seen stainless steel used in some commercial yagi designs, but SS has greater losses than AL. On the other hand, the I^2R losses in each yagi element can really add up, but not so much in a collinear antenna like a 4-bay.

The phasing lines in a collinear antenna do provide for some impedance transformation, but this impedance transformation varies as the receive frequency changes.

I suspect that these fat elements have lower impedance than the Winegard HD4400 modelled by holl_ands. With NEC2-based software, I suspect they would be best modelled as 4 (or more)parallel wires, separated by the diameter of the tubing, joined at the ends.

 

[old sparks]

Its all so much easier if you use just 4nec2 or any other NEC engine which account for the relationships, heh.

^this^

Hol_lands provides the NEC input file on his wonderful webpage.

Admittedly, there would be a loss of cardiovascular exercise from the reduction in 'handwaving'

 

[old sparks]

Good point about testing antennas, stand far away as your body acts like a resonator.

Heh! I mean handwaving from a design perspective.

http://en.wiktionary.org/wiki/hand_waving