I started out by building, then buying, crossed dipole + reflector antennas for my 137MHz WESAT work. That was back in 1992 when I was in Darwin N.T. When I returned to the UK, the biggest problem was interference from Pager signals at 139MHz. That required better receiver disign rather than a better antenna though. Crossed dipoles work well and are easy to build accurately. The down side of them is that the have a null directly above them.
Over the years the QFH has become popular. I have made them and they do work well. As a first antenna build they can be a little daunting though. I was happy that I started with crossed dipoles and proved my comp,eye receiving system, before trying a QFH. Commercial QFH antennas used to be very expensive when compared to crossed dipoles.
My commercial maritime WESAT system from ICS uses a very high quality crossed dipoles antenna rather than a QFH. That ICS crossed dipoles performs very well indeed, but was very expensive new. There are pro's and con's to both antenna types.
A decent receiver with the correct IF bandwidth is also important for best results. Normal NFM and WFM IF filters found in commercial scanners are far from optimal. A 50kHz IF filter bandwidth is about right.
Fraser