MTS DOES NOT ENDORSE THE ABOVE LINKS, ANGELFIRE ADDED THIS
Filters We have been getting allot of calls about where to find ICOM filters (since ICOM no longer makes them) We have found the INRAD (International Radio) filters to be as good, if not better than the stock/optional filters that ICOM made. Many of the filters are 8 pole, which offer superior selectivity and noise floor performance. They even have filters to enhance your rig (yes almost all makes) that the manufactures never offered! Instalation is well documented, and designed for the Ham to do. If you need assistance, we would be glad to help. If you would like us to do it, we can do that too.
INRAD's informative website is here. INRAD Crystal Filters