I recently released some production changes to the AL572 and AL811H
amplifiers to reduce the chances of damage to radios when tubes fail.
The same basic changes apply to the AL811 as are outlined on this page:
http://www.w8ji.com/arc_protection_al572.htm
These are now factory production changes, including the addition of the gas
protection tubes.
The gas protection tubes are a good idea for multi-op contesting
environments in close quarters.
:-)
The biggest single change to extend the service reliability of an 811H amp
would be to swap in 572B tubes. It won't run more power, but it will take a
whole lot more abuse and misuse to hurt the tubes.
|