[Amps] 3CX1200Z7 backup tube?

[Bill, W6WRT]

For what it's worth - I always caution guys about the AL-1200.

If you only run CW and SSB you should have no trouble. On RTTY however
you should hold the power down on the low bands. Twice I burned up the
tank coil on 80 meters during a contest. The first time the tap for 80
meters got so ho it unsoldered itself. After doing a better solder
job, on the next contest the polystyrene rods supporting the coil
melted and the coil twisted itself into a deranged Slinky. 

I sold the amp to a non-RTTY guy, but if I had kept it I would have
cut a hole in the side of the cabinet and mounted a fan to cool the
coil.  This was an old model, circa 1995 or so. Newer ones may have a
more robust tank coil. 

Just a word of advice. 

73, Bill W6WRT