This thread began as a project to put a full wave Loop Skywire into the air at one wavelength high. It progressed into a 2 element Quad beam.
I have a loop in the attic, but I decided to take a loop outdoors, so I built a 11 meter quad loop and parked it horizontally at 30' elevation.
It is only 10' above the roof ridge. Here are some photos of the building process. Just ask if you don't follow the photos.
The difficult part is done.
With the SWR meter it is 1.1:1 on all CB freqs.
I'll get the analyzer on it maybe tomorrow.
It has a 1/4 wave 75 Ohm matching section on it.
Here are the materials and step-by-step instructions on this single loop:
Here it is:
The dimensions are dictated by the length of the wire, which is viewable in the photo of the calculator I used to determine the wire length, spreaders, etc.
The parts in the above photos are:
two sets of 2" x 8-32 SS screws and nuts with washers.
3/4" soc PVC caps qty 3
3/4" tee all soc
2 feet long 1-1/2" PVC tube
3" x 1-1/2" adapter
6 inch length of 3" PVC tube
one stick of 10' x 3/4" PVC
2 sticks of 1/2" x 10' EMT (conduit)
prepared 6' piece of 75 Ohm coax
some tape to wrap around the EMT to take out slack between its diameter and the ID of the 3/4" PVC.
1. Take the 3 x 1.5 adapter and remove the stop inside the 1.5" end so the 1-1/2" PVC tube can go all the way through a couple inches. This is to make it sturdier than if the stop is in place. Glue the two pieces together as shown in the photos. I used self-drilling screws also for reinforcement.
2. Glue the 6" x 3" PVC tube into the adapter. I used self-drilling screws for reinforcement.
3. Drill two sets of holes into the 3" x 6" PVC tube at 90° to each other offset from each other.
4. Insert the two joints of EMT through the offset holes. Be sure they are inserted half way their lengths. This will form the characteristic cross shape of Quad spreaders. Secure them to each other in the center as you see done in the above photo. This provides stability and assures the spreaders remain in place.
5. Cut the 10' joint of 3/4" PVC into 4 equal parts - 2.5' each. Place caps on three of them, and the tee on the fourth.
6. Drill holes through the ends/caps of the three capped pieces of PVC so the wire can pass through them. Drill two holes, one in each end of the tee for the connector end of the loop as shown in the photos above.
7. Wrap sufficient amount of tape around the EMT spreaders to remove slack between the 3/4" x 2.5' sections when they are slipped onto the spreaders. Do this near the end of the EMT, and at 49" out from the outside edge of the 3" PVC center tube.
8. Slide the PVC sections onto the four EMT spreaders. Thread the pre- measured, pre-cut wire through the holes of the three caps securing the ends of the loop wire with the SS screws on the two sides/ends of the tee. Slide the four PVC sections out equally from the center until the wire is taut.
9. attach 6' piece of 75 Ohm coax. Tape or zip-tie this along the spreader . Done.
Some have said it's hard to tell whether the loop is mounted vertical or horizontal. I hope this helps:
Well, It went up on its edge:
and then because I already had the director stored behind the shed it grew and appendage:
It is 5' 8" spacing.
This photo does not represent the completed project, only what I have now.
Some more work on the antenna.
The driven element is two 18 gauge stranded wires twisted into one.
The reflector is on a hub identical to the driven.
The 2el quad is now 37' to the boom.
The spacing on a new aluminum boom is 80". It seems to have a tighter beamwidth than it did at 74", my last spacing.
Thanks, Paul.
It would be fun to work something up together.
Some of the comments in the post may seem disjointed. It is because I lifted the materials for the thread from a lengthy discussion elsewhere and dropped them in here for the benefit of clusterdx members.
Because I was using the antenna at three different stages over a period of time to each stage it evolve over several weeks to the complete 2el Quad beam.
It was
1. a horizontal loop
2. A vertical loop
3. And a two element beam.
The two element beam had a short run as a Quagi using a dipole type director before I replaced it with a loop reflector. If I recall I thought it demonstrated better side rejection as a Quagi at the time than as a Quad. Looking back I may have noted that at a time when the loop was fed for horizontal polarity.
I am going to have a go at building one of these .. I know this is an old post - But thank you for sharing,
If you do call back to view this thread Charles can I ask - Where did you find the CALCULATOR - could you please post a link.?
Thanks again for sharing
Best Regards,
Peter. 29PD01
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