1

2
Original tubes and chimneys

3
Left rear tube with chimney that failed

4
Plate tuning

5
Plate tuning and meters

6
Roller, Plate tuning, meters

7
Amp Front with covers off

8
Failed chimney
(click here for more pictures)

9
Tube that had failed chimney

10
Rear panel removed. Obvious heating on tube near rear panel.

11
Closeup of hot spot

12
Another view of tube with the hot spot.

13
Rear of amp

14
Bottom of amp with tubes removed

15
Odis tightening cooler on new tube.

16
Odis looks at the old tube

17
New tubes and new PTFE chimneys I make, left view

18
New tubes and PTFE chimneys, top view

19
Amp from top right with new tubes and chimneys

20

21
Rear view

22
Meters after wiring change

23
Amp with power on.

2/18/06 We used the W4ZT tube tester to test the old tubes; they were unbalanced and difficult to bias down. New tubes and my PTFE chimneys were installed, a W4ZT bias board was installed replacing the zener and the air opening into the rear chassis was widened.

24
Back on 2/18/06 with new tubes and bias board installed

25
W4ZT bias board up close

26
Under side after mods

28
New tubes, chimeys and new plate blocking cap in place.

29
Another view of plate blocking cap and tubes

30
Over all top view

32
Also new bleeder board

33
NEW TUBES GLOW!
These are new tubes and as you can see the left one is glowing faintly blue and the right one is green!

34
Close up of blue glow.

36
Over all glowing tubes. Amp is keyed and making lots of power.

37
Meter's against the peg

38