I try to be a "DIY" type of guy

When my 1st Gen Iphone LCD broke, I bought parts to replace it. Long story short, heres what happened

1) replace LCD screen
2) attempted to replace battery (bad solidering job but got it done)
3) ripped wifi cable during #2
4) replace wifi / cell atenna
5) replace with new battery
6) Upgraded to 2.0.2 software (bad reception)
7) downgraded back to 1.0.4 software (still bad reception)

I really dont know what other part there is to replace. While standing still, the reception is fine but when the iphone is on the go, it loses reception quickly and conversation fades in and out.

What else could be wrong? I spent so many hours working on this I just hate to throw this phone away or sell it for parts.

Please advise