777 MHz scanner antenna

I made this j-pole to connect to my SDR scanner.  The included STL's are for the 3d printed radome and the base. The antenna element is #10 bare copper ground wire.  I purchased some 10' long SMA Male to SMA Male assemblies off amazon and cut them in half to solder to the antenna element.  Dimensions for the #10 copper antenna element:

772 MHz Downlink Frequencies: 10" long side, 3.35" tuning stub, 0.875" separation

856 MHz Downlink Frequencies: 9.125" long side, 3" tuning stub, 0.875" separation

You will need to use a VNA or antenna analyzer to find the 50 ohm feed point.  I stripped the coax and held it up to the antenna where I thought it should be soldered.  Then I slid it up or down until I got good return loss in the desired frequency band.  I marked that point with a sharpie and soldered.

I made two antennas because I use two Airspy SDR's to scan.  One is tuned to 772 and the other to 856.  You could split the difference in the measurements above and make a single antenna for a SDS200 Scanner or similar equipment.  Just buy the coax assembly from Amazon with the connector you want so you don't have to terminate the coax.

I printed the base upside down.  I used supports to help with bed adhesion and also the bridging inside.  This puts the supports inside the base where you can not see them, for a more attractive looking base.  If you have awesome bed adhesion, you may not need supports.  I printed the radome on it's short side with a  brim and a draft shield to prevent warping.  The radome is a neon green PLA from Amazon, I don't remember the manufacturer name.  It was whatever was cheapest on Amazon that day.  The base is Prusament Galaxy Black PLA.

I added another STL.  This is a form to help bend the wire to fit into the radome.