[Erythros]

First question is have you flashed your ROM or anything else since you noticed your signal degrade?

I did notice a reduction in EV coverage after flashing my ROM with JMZ's ROM, which I still use and love.
I then upgraded to Radio version 1.07.06F found here on PPCGeeks.com and my signal is moderately better. (Much more EV and much less 1X)

My suggestion would be to flash the radio to the latest possible and work backwards from there after testing on your phone for about 1 day per radio and see which one works best for you in your coverage area.

The nice thing about flashing your radio is while it flashes your phone in a similar manner to how you would flash the entire ROM, you are usually not required to HARD RESET your device.

I always do a lot of research on the posts before attempting a flash of my ROMS because more than likely you can find the answer you need before having to ask or before screwing up your phone.

As always, backup your PIM information before proceding with any flash.

Disclaimer: Read the instructions for each radio rom, read the posts following the release of each Radio Rom, and good luck.