Building the V-Hawk, by Ronbo, RevA, 6Aug2015
The V-Hawk is Approximately 50 1/2 inches tall by 41 inches wide. I built my V-Hawk from 14-gauge, 0.061" thick T6061 Aluminum Sheet. I then glued / taped it to plastic sign board. The project took a Day and a Half, and support for the harness still needs to be addressed. By the time I get that done, plus a way to angle it 30-Degrees/45-Degrees/60-Degrees it will be the better part of two days. This is a project for experienced antenna builders. This should not be your first attempt at a harness. The method used by me is for an indoor/attic installation ONLY. It is NOT suitable for outdoor use.
The V-Hawk has two bays and a connecting harness. The centre to centre vertical separation between bays is 0.71M.The dimensions of a bay (in Metres) are shown in this photo. X=Depth, Y=Width, Z=Height. The Bay is symmetrical about the Y Axis & Z Axis.
They are repeated here, for the top right Quadrant of the bay.
X=0,Y=0,Z= 0.283
X=0, Y=0.393, Z=0.223
X=0, Y=0.151. Z=0.102
X=0, Y=0.507, Z=0.0541
X=0, Y=0.08, Z=0
To complete the layout of one bay, repeat these measurements, changing all the 'Y' values to negative. Then repeat again, changing the 'Z' values to negative. Values given are to the centre of the element, and I made all the elements 0.01M (1cm or 10mm) wide. Also note the harness, which you will have to layout from the photos.To improve accuracy, I made Quad paper (apx 1cm by 1cm) in excel and printed it on large paper. I was 5 hours doing the layout. Remember you also have to layout the sign board, so when the antenna is cut out you can attach it accurately.
Once laid out, I drilled small holes in the aluminum at all the inside corners. Do NOT drill holes in the harness!!I also drilled several 1/2" holes to facilitate cutting. I cut the aluminum with scissors. At the four sharp inside corners (X=0, Y=0.393. Z=0.22) the inside hole was drilled 3mm from where the lines intersect, and I removed 3mm from the sharp outside edge to round things off a bit. (The dimensions given take this 3mm 'sharp corner rounding' into account). Aluminum sheeting is sharp. You have a choice-you can wear gloves for the afternoon, or bandages for a month. Safety glasses are also mandatory. Cutting the aluminum took 5 hours.
Once I was done cutting, I glued the aluminum to the plastic sign board. Use an appropriate glue. I used tape to hold everything in place. When done gluing, I weighed it down and allowed the glue to dry overnight.
The next morning I drilled two holes where the 75:300 Ohm Transformer (aka Balun) goes, then cut the centre 2cm vertical strip of metal lengthwise. I could have made this cut prior to gluing, but I was concerned I would end up with a tangled mess if I did that, so I deliberately left this cut until now. Once the harness has been cut, fold the harness upwards by bending the feeds midpoint. I used a pen to ensure a gentle bend.
Patch the break in the electrical continuity (two locations-Orange in photo) where the harness intersects the driven elements of the antenna. Use a remnant to build these two patches. I sanded everything first, then attached the 'Patch' with tape.
Install the balun, (note hole in whiteboard for this purpose) fold at the appropriate angle,and start using it. When installing this antenna, it MUST be vertically plumb.
While this picture was being taken the antenna was picking up physical channel 23 from 92 miles away with 100% reliability & no pre-amplifier. It was mid afternoon and there was no tropospheric enhancement.
A means to support the harness needs to be improvised.
Develop a way to ensure the fold of the antenna is precise- that is secure it top and bottom and ensure the fold angle is consistent.
The sides of the antenna fold out slightly in the middle due to the antenna's weight and height. They need some form of reinforcement.
Finally, if you fold the antenna 60 Degrees, the vertical feeds of the harnessalmost touch. I manually revised the bend points of the harness and kept the gap per spec. This slight revision has minimal effect on performance.