[Amps] GU74B's

[Dave Hachadorian]

As several people predicted, my pair of GU74B's does not 
seem to have been damaged by accidentally running them 
without filament voltage. All is fixed now.

Incidentally, this amp is a TenTec Titan III, Model 417. The 
TenTec service tech says this is not the first time they 
have seen this failure in the filament wiring. They 
recommend, and routinely install, a modification to route 
the filament transformer leads more directly to the tubes, 
thereby eliminating a pair of wimpy plugs/sockets in the 
cabling:

1. Unsolder the two green filament transformer leads from 
the Screen Supply Board.
2. Using #18 wire, extend those filament transformer leads, 
bringing them to terminals P1 and P3 on the Input Match 
Board, where the tube filaments are connected.

Did the mod. 50W in / 1500W out. Thanks for your help.


Dave Hachadorian, K6LL
Yuma, AZ



































.