try this simple antenna made from coax cable (and you can use RG-174 cable which is the same diameter as 16Ga wire). make the dimension for each of the two elements (the exposed center wire and the folded-back braid) equal to 19cm. you can skip the part about copper tubing, and just fold back 19cm of the ground braid over the cable insulation. keep the braid intact so it acts like a metal sleeve over the outside of the cable. this will give you a good half-wave dipole (each element, the folded back braid and the center wire are each 1/4 wave) that doesn't need to be supported because it's the end of the cable. at the other end of the cable, the center wire connects to the transmitter antenna terminal, and the shield braid connects to the transmitter ground (either a metal shield or a ground trace on the pc board will do)