Thanks to all of you who responded.

73, Doug W3IIY

Ken Scharf wrote:
Chris Suslowicz wrote:

In article ,
Cmd Buzz Corey wrote:


COLIN LAMB wrote:


"I am planning to replace the four 811A's in my AL-811H amp. Is there
anything special I need to do to accomplish this?? I have read
about "burn
in" but is there anything else?


There is no reasone to "burn in" tubes.



Apart from mercury-vapour rectifiers and thyratrons, of course.

Chris.

In amps with multiple tubes in parallel it is a good idea to use
matched tubes if possible (you can get matched 811A's). Some amps
have bias adjustments for each tube so you can match idle current
on the tubes (don't think yours does though). IIRC the amertron
4 tube 811A amp DOES have a small neutralazition cap, the 3 tube
one does not. The manual should tell you how to adjust the
neutralization, however in most cases it only matters on 10 meters.