E88CC 6922 Amperex tube with Telefunken print 

• US tubes
• all same very strong tubes
• Acid code 7L6 *2F all of them
• code on top 288

Emission all tubes same = Gm 13,500.....15,000  (100% = 12,500 ±2,500 )
Current  all  tubes same = 22....23  mA  (100% = 15mA)

Produced by Amperex NY