[Amps] Amperex 3-500G

[John E.Cleeve]

Good afternoon gentlemen,
Thank you for the response to my plight. I did check the tube socket  
bases for signs of heat dissipation, changes of plating colour etc. 
but the only signs of any stress is on the tube pin. It is curious, to 
me, that the problem has occurred on the same pin, on each tube. I 
will examine the springs once again, and maybe fit additional clamps 
to ensure that the heater socket/pins remain a tight fit. Sincerely, 
John. G3JVC.