Screw driver antennas are nice but I find them lacking fot 75 meter mobile, so I use a 6 inch bug catcher, but it is not convenient to QSY as you need to change taps for even a few kHz change. Instead of changing taps I mount a tuning stub just below my capacity hat made out of a portable radio telescopic antenna and a bronze electrical ground clamp which you can find at Home Depot.
Drill the set screw hole on the clamp to the antenna diameter, sand the plating of the end of the antenna and then solder them together. Mount as shown and with the antenna collapsed tune the bug catcher to highest freq desired on the band. I find that I can cover about 150 kHz on 75 and the whole band on forty. You can carry a measuring stick and notes st be able to quickly adjust the antenna to a desired freq.