Ground Plane Antenna 868MHz Meshtastic

Ground Plane Antenna 868MHz (or for other frequencies like 433MHz or 915MHz) for Meshtastic or anything else

i used 1,5mm² (1,4mm diameter) copper wire to find in Europe in the standard NYM cable

or AWG 14 or 15 in the US

-stretch the wire with pliers and benchvice to make it straight

-calculate the wire lenghts (for example here: https://www.dl2fbo.de/lamda-1-4-groundplane/)

and cut them plus a bit extra lenght (plus 10mm or ½")

-you need a proper SMA Pigtail connector

-cut of the IPAX Connector and throw it away

-maybe drill the hole maybe a bit larger to the wire diameter

-the copper ring i made out of the same wire

-bend the ring around a drillbit or somethine

-put the radials through and solder them kind of quickly to the ring

-put a little bend to the top wire to make it more accessible

-put the coax cable from underneath through the hole

-remove 6mm or ¼" of the outer insulation

-wrap the shield so one side, twist an put solder on it

-remove some millimeter or some 1/8" from the inner insulation and prepare with solder

-solder the shield to the ring and the core wire to the top beam

-put the cap on with some silicone or glue

ideally tune it with a VNA

My wire lenghts are for 868MHz 

-the top beam is in total calculated 82mm; measured from the the top plastic tip on the outside 61mm long

-the four radials are in total calculated 92mm; measured from the plastic ring on the outside 81mm long

printed mine on a Bambulab X1C with PETG