I received as a gift a pro-2018 scanner, purchased at Radio Shack.
Any help with the following issues would be apprec iated

-The frequency for SFO tower is 120.500. However, on that frequency,
I can only hear transmissions coming from the aircraft, not from the
control tower.

-The frequency for the local police department is 488.312. However,
after entering this on the keyboard, only 488.300 shows on the
display. The transmissions are somewhat scratchy.

Any way to improve the above.

Thanks

Don