really the only thing you can do to the radio is make sure it is aligned, and that it is receiving on frequency. Although this unit has a frequency counter that will tell you where it's receiving, you cannot successfully put the radio on frequency unless you fully align the radio. In order to align a radio you need a volt meter, watt meter that reads avg watts, and an oscilloscope.
A volt meter and watt meter is easy to come by, however the oscilloscope is an expensive piece of equipment to attain.
You can just as easily tune your clarifier to the correct receiving frequency on the counter.
An easier way to improve your receive on any radio is to make sure the antenna is tuned for best SWR. When an antenna is tuned to the proper length for the best SWR your receive will get better because your antenna will be on Que.
There is also a Schottky diode upgrade that can be done. This consists of changing the detector diodes in the radio to schottky diodes as well as changing a transistor. This mod improves receive in most galaxy radio a great deal.
You can get these as a kit with full instructions on ebay fairly cheap.
You need to replace diodes D1, D2, D23, D24 with the schottky diodes in the kit, then replace TR-17, with the transistor that comes in the kit. Then remove TR-14. and them remove TR-19, and put the transistor from TR-14 in the TR-19 spot.
The Transitor that goes into TR-17 is a 2sc2999. I can't remeber what the Schottky part number is. But like I said, they sell the kits with complete instructions on ebay.
Here you will find all the technical information about your radio, as well as alignment guides.
Here is a link to ebay with an upgrade kit and instructions on ebay.