Here is the N4TZE, 3 element, 6 meter quad antenna I just finished. This antenna is tuned to 50.130mhz. I used an IFR 2393A, that has its own tracking generator, which I put to good use. It would have been extremely difficult to get this antenna resonant on 50.130mhz without it. This antenna is constructed with the following materials....1 1/4 inch pvc mast that is 5 feet long, 1 inch pvc boom that is 5 feet long, the spreaders are 1/2 inch pvc, screws, nylon rope, and hot glue. The pvc is schedule 40 type. The parts plus the glue was cost $35.00 dollars. I had to get 6, 10 foot pieces of 1/2 inch pvc for the spreaders.
Antenna tuning is completed and before painting. Note that the boom support is not shown in these before pictures. The reason for this is that I wanted the hot sun to beat down on the antenna to see how far it would sag. After a couple of hours of looking at the antenna, and thinking about the possibility of ice, I added the boom support and nylon rope. The boom support was glued into the 1 1/4 inch cross where the mast is. I had enough forethought to use the 1 1/4 inch pvc cross, thinking that maybe I needed to add a boom support.
This is a picture of the feed point where I utilized a variable ceramic capacitor, which is about 2-9pf. What you do not see is that I added a 18pf ceramic capacitor in parallel underneath the variable capacitor. I need just a little bit more capacitance to get the deep resonance I was looking for. There is a calculated length of 75 ohm coax which is the matching to the 50 ohm coax feed line. The measured antenna impedance is 48 ohms. I applied coax seal, that sticky, rubbery substance around the capacitor to keep water out of it.
Here are some close up views of the boom that is going through that 1 1/4 inch pvc cross. See the spreaders that are sitting on a 1 1/4 inch to 1/2 inch pvc tee. See the short piece of 1/2 inch pvc coming out of the tee. The brown spot is where I heated that up with a torch and bent it to match spreader arm. I carefully mated that 1 1/4 inch tee to the spreader using spots of hot glue, a little at a time. Once the glue cooled, I applied a lot of hot glue to fill in the gaps, then added a long threaded bolt through the 1/2 inch spreader, and a long sheet metal screw close to the middle of the 1/2 inch pvc cross, the center of the spreaders.
The pictures below are of the finished 6 meter, 3 element quad, that is painted brown. See the boom support! It helped to add a little up tilt. The picture on the left shows the elements from left to right, director, driven element, and the reflector, see the up tilt? The back side of the antenna is the end of the quad with more boom sticking out. I worked VP5VAC with just 100 watts. The antenna has deep nulls off to the sides, and great directivity.