I would try to stay away from the "A" as its the oldest of the series it will be hard to get some parts. They made changes to each series as they were built.
There is a place here in the Chicago area that repairs the 2001 series Cardinal Electronics in Arlington Heights Illinois. Good Luck, I had a R2001-A that took a power surge and it was un repairable. "73" Paul R. Dumdie Jr. W9DWP/R IRLP-NODE-4455 443.025/2A 145.270/1B/1Z/NAC-293 ARC-Radio-8 KCARES HERD546 EX WB9QWZ WQGG738 AAA5CU/T
