This is very inexpensive GP Antenna for 2m band. Material for making antenne is,
One Conector S0-239
4X50cm AL. rods of 2.8mm
1X50cm Copper rod 2.8mm
4 couplings for creeping cables
NOTE - you can use 3mm rods - not critical .
Simply connect coupling with a screw on its SO conector and tighten. At the other end putting AL rods, tighten and bend at an angle of 45 °.
In the radiating element, use a copper rod, but also we can use and Al. rod.
The recommended length for the frequency 145.MHz. are
radiating element 49.5cm
Length is not critical, and we can leave the elements a little longer. By connecting antenne on the SWR meter can is easily adjusted to 1: 1.1 to 1.2. SWR. Just cut the elements a few mm.
This antenna is not of sufficient strength to withstand high winds, but as a backup, portable or balcony antenna will be very useful. I recommend the power up to 50W FM.