[Amps] AL-1200 3CX1200Z7 Tube

[Dennis W0JX]

The AL-1200 is now supplied with the 3CX1200Z7. The change was made in early May and Ameritron had the amp with new tube on display at Dayton this year. There are several circuit changes, mainly a different filament transformer, different chimney, no socket, and the neutralization circuit has been removed because it is no longer necessary.

There is an interesting sidelight to this change. The catalog at Dayton advertised the AL-1200 with a 3CX1200D7. The engineers told me that they ordered a bunch of these tubes from Eimac but could not make them work properly in the AL-1200 chassis. Fifty D7's were sent back to Eimac and the switch was made to the 3CX1200Z7.

This should serve as a warning to AL-1200 users with the A7 tube. That version is going to become "unobtainium."

73, Dennis W0JX