Here is a simple, low cost, easy to build quarter wave antenna that works great for many people. It can be used for scanning or with some adjustment as a base antenna. The radials can be made of easy to find number 12 solid copper wire. The vertical radial (A) should be soldered to the center connector of the SO239 and sealed with RTV or another good sealant around the center pin to keep water out. The four base radials (B) should be about 5% longer than the vertical and can be soldered on or bolted to the SO239 mounting holes using 4-40 machine screws. The base radials should be bend downward at about a 45 degree angle and then adjusted as needed. The antenna can be mounted by attaching the PL259 to a mast or wooden dowel rod with a hose clamp, or by passing the coax through a 3/4 PVC pipe. Make each radial a 1/4 wave of your desired frequency plus a little extra. The extra will give you some room to trim things up when you adjust the SWR.

Try this Antenna Calculator for approximate finish lengths.
Some examples starting lengths:

Freq :146mhz
A = 19 1/2 inches
B = 20-1/2 inches
Freq :446mhz
A = 6 1/2 inches
B = 6 7/8 inches