[Amps] unstable Ameritron AL811

[simon@creoch.freeserve.co.uk (simon@creoch.freeserve.co.uk)]

Hi all

I am chasing an AL811 that its owner says is unstable - symptoms are unstable 
standing current at rest with no drive.

The amp has been sitting for 2 years unused.

Could this be caps reforming, gassed tubes, or the amp turning into an 
oscillator (TPTG!)?

any ideas anyone!

regards

Simon GM4PLM