Back in 2012 I was having issues with com static on a 430W. After installing an alternator noise filter, replacing the ELT and adjusting the squelch on the 430 everything was great. Now, on the last 2 takeoffs the static is back BUT... it only lasts up to around 2,000 AGL then falls off. Climbing to 8,500 then is quiet, cruise is quiet. No power adjustments in the climb and minimal static, if any, in the descent except around 2,000 AGL then all quiet down to the pattern and landing. So it's mostly a full power thing but only up to around 2,000 AGL...hmmm...??? First guess is the noise filter is going bad? Any other thoughts?