Due to it's size, I was reluctant to model Hi-VHF 4-Bay Bowtie w Reflector Screen,
esp. knowing that it might take several HOURS to run, assuming 2inx4in Grid Size.
And NO, you can't simply make it smaller to reduce the Gain a bit without ALSO
totally messing up the SWR...for example babblin5's way too small 4-Bay U-Tube Defect...
F/B Ratio with Reflector (at about 3 x 4.5in = 13.5in Seperation) would be in the
range of 15-20 dB, similar to UHF CM4221, if it were Rescaled....more for Angled Reflectors.
Hi-VHF 2-Bay & 4-Bay dimensions were tweaked for Hi-VHF Band, so a 4nec2 run would be
needed to find out for sure....and mounting it near the ground also needs to be modeled....
If you want a smaller antenna, consider the 5ftx5ft Hi-VHF 2-Bay Bowtie:
Or the smaller, lower Gain Hi-VHF Loop with Screen Reflector...or the simpler, but
even lower Gain Hi-VHF Loop with Loop Reflector, with high F/R on ONE Channel:
An array of Reflector Rods can be used in lieu of a Screen Reflector (like CM4221HD).
But I haven't (yet) modeled this configuration with the Hi-VHF antennas to determine
the "best" Lengths and Spacings.....but I think this approach would COST MORE....
Bear in mind that the Size of the Reflector Screen can have a profound effect on
Gain. If it is too small bad things can happen to Gain and SWR....up until the point
Gain pokes out the BACK of the antenna!!!
Also bear in mind that whatever building is behind the antenna is acting as a very
large Reflector, whether you intended it to or not. Walls can be metallic, such as
the chicken wire in stucco or Aluminized Foil in insulation....or moisture in wood.
To estimate what an enclosure does, a 4nec2 run should be undertaken, using
different sized enclosure models surrounding the chosen antenna model....