I have seen some comment on power amplifier tubes for the above Drake transmitters, but I would like some definitive information. My T-4XB uses 6JB6 and the T-4XC and TR-4C use 6JB6A's. I do not know the brand names on the current tubes as I have had no need to open the cases.
1. The 6JB6-6JB6A should be interchangeable as long as all tubes are the same in one transmitter? 2. I believe I remember that Sylvania was the tube of choice? Are there any other manufacturers' tubes that will work satisfactorily? Are there any that absolutely will not work? 3. Are there any substitutes (6KM6) that will work? I have seen 6KM6's on the auction site that are claimed to be excellent substitutes. 4. If this has been hashed out before, please tell me and point me to the archives. Thanks. Dick KC9UB
