2 Element Quad Project

The whole assemlbly weighs only 21 pounds.

This antenna is being built for 10 meters centered at 28.400 Mhz.

In this image you can see the antenna under construction. Note there is only one strut added at this point. The hardware and support strings and cable have not yet been added either. Click on support strings in the navigation bar to view that part of the construction. 

A step ladder is a very handy tool during construction.

The next two images show the 1 1/2 inch 5 way cross assembly.

All joints are connected with pvc pipe cement. The telescoping couplings are cemented into the 1 1/2 x 1/2 inch bushings, then cemented into the cross. The assembly is attached to the boom also using cement. Boom is also 1 1/2 inches.

It is from the center of this cross that you will be using to make some of your measurements for constructing the spreader arms. Don't cement your spreaders just yet. That will come a little later.

When measuring to cut your boom you must take into account the depth at which it seats into the cross.

This image shows one of the telescoping couplings or spreader arm adjusters extended to show you that you have approximately 2 inches of play when you extend these to tighten up your antenna wire. These are clamped off at their base to stop them from telescoping back in with stainless hose clamps. The one on the upper right has been extended.

When making your measurments for cutting the spreader arms keep the adjusters compressed and subtract 1/2 inch from the total measurement to place the adjuster in the desired slightly slack position for the antenna wires.

This image also shows the alignment between the two cross assemblies. You only have a couple of seconds to align them when cementing. An alternate method would be to bolt one of the crosses to the boom if you feel you would like to do so.

This image shows the connection point for the antenna wires to run through. After measuring and marking your antenna wire you will run the wire through the holes you have drilled in the connectors and tightening the pvc plug onto the wire. This basicaly crimps the wire in place.

Now you can cut your spreader to the desired length, keeping in mind to take into account the distance the spreader arm fits into the connector and the adjuster. The connector is a 1/2 inch slip X 1/2 inch FPT.

This image shows the feedpoint on one spreader arm of the driven element. It is assembled the same way as the last spreader arm except you have two connectors instead of one. The reason for this is so that you can have the antenna wires held solidly in place and have a slack area for your connection to your co-ax cable. This is where you will adjust your SWR by lengthening or shortening your antenna wire. Since the wires are slack in the middle this design makes adjusting easy. Diamond feedpoint shown.

These next two images show the connection point of the strut. The measurement of the strut is the same as the boom length. Note the modified tee connector. Saw about 1/3 off the side of the fitting. This will make it a snap-on connector that can be easily adjusted later. I found out later that they make snap connectors. Oh well, I used the ones I made anyway. These are all 1/2 inch pipe and fittings. 

Here is the strut mounted to the spreader arms. In the finished design I have the strut placed 3/4 ths. of the way out from the adjuster.

Some other construction notes:

The primary mast is 2" galvanized pipe which measures  2 1/2 OD obtained from a salvage yard.

The secondary mast is 1 1/4 EMT steel tubing that measures 1 1/2 OD purchased at Lowes.

The PVC boom is 1 1/2 " with a 1 7/8 OD purchased at lowes.

Muffler clamps were used in all clamping methods. The primary to secondary mast connectors are made with 4 clamps, 2 on each side of a 1/8 inch steel plate that measures 4' X 8". Clamps were bought from an auto parts store. plates were gotten from a salvage yard.

Support strings are 3/32 Dacron purchased from The Wireman.

Rotator purchased from Walmart Online.

All parts were purchased with price, quality and weight in mind.

Rotator support bearing purchased online.

All tape is waterproof  roof flashing tape used to seal wire connections and secure the cables to the mast, purchased at lowes. It is made of rubber, thick and very sticky.

Spreader arms and struts are 1/2" PVC pipe.

Telescoping couplings for spreader arm adjustment are actually used for  PVC  pipe repairs.

The snap connectors on the end of the struts were reinforced with small screws.