This is a jig for making your own left hand circular polarized FPV 5.8GHz cloverleaf video transmitter antenna for your drone or other RC craft. The information for creating this jig was taken from information provided by a guy named Oscar Liang. The website for creating the antenna including all calculators for the lengths of wire needed to create the antenna lobes can be found here: https://oscarliang.com/make-diy-cloverleaf-antenna/
A properly constructed FPV antenna is one of the most important parts of an FPV video system to get the best range from your setup. My reason for making the antenna was to upgrade the dipole brass antenna on my micro FPV transmitter/camera setup that I purchased some time back from Amazon in the hopes of increasing the transmit distance from the video feed.
I created the antenna using the above pictured 6 inch bulkhead style RP-SMA extension cable purchased from ebay. I cut the female end off of the cable leaving enough cable length for me to slide the cable into the grove on the jig and remove it with the lobes attached. The leftover Male section of the cable replaced the original dipole brass antenna on the transmitter and gave us a connection point for the new cloverleaf antenna. I will make a mount for the transmitter and male cable end to fit it to one of the arms on my hexacopter.
Using the information on Oscar Liang's website I created all of my wire sections using a strand of 1mm center conductor wire from an old piece of RG6 cable. Once I had the 3 lobes made, I stripped the plastic coating from the end of the cable about 2 to 3mm. I folded the braided shielding down and separated it into 3 even sections and twisted them. I also stripped the center insulator as close as I could to where the shielding was folded down. Next I soldered one end of each of the 3 lobes on to each of the 3 braided twists I just made. Once those are soldered on, it's time to put it in the jig. The jig is used to perfectly space the lobes at 120 degree angles to each other, and lay them at the required 45 degree angles to each other. Once you have the lobes laid on the jig, bend the last ends of the lobes out as close to the center conductor as possible and solder the 3 ends to the center conductor while it is in the jig. Once that is done, you can remove the antenna from the jig and you are done.
After the antenna was made, I soldered the leftover male section of the cable to the transmitter.
When I first tested using the original dipole antenna the picture was slightly, but noticeably grainy, and that was with the transmitter right near the receiver. After connecting the transmitter with the new antenna and running a quick video test, I have to say that the video signal received at my laptop was crystal clear. I saw none of the graininess that I saw with the dipole antenna. I have not flown the hex with this setup yet, but I have a feeling that the results will be positive.
Read the information on Oscar Liang's website very carefully and make the antenna right the first time. Using this jig will help you achieve that level of quality that will help your antenna perform at it's peak.
If you find any errors in the information I provided, or have any other questions on this, feel free to leave a comment.