I have had good luck with an antenna mounted Channel Master Triton III
preamp.

Some other thoughts.

New antennas pick up a signal better than an old corroded antenna.

Coax and twin lead wears out due to weather and sunlight. It may be marginal
and need to be replaced.

A good ground might help signal reception.

The higher the antenna the better the signal.

Any trees grow up in the way of your antenna over the years ?

A VHF/UHF combo antenna is a compromise. A seperate UHF antenna might do a
better job of pulling in the weak signals.