06-08-2020, 07:42 PM
It's a Roberts R600, seems a very much less powerful amp than on the Hacker, also 9V rather than 18V.
It could be something other than whiskers or junction. Whiskers are obvious tin dendrites due to too much pure tin plating. I've repaired a leg snapped off at the body, but I don't trust zapping. What about 6 years or 10 years? The tin dendrites grow slowly, but EVENTUALLY they will come back. It's a production defect and NOS Russian military and other parts are available cheaply. I'd have a different view on replacing parts in a pre-1929 set, and I'd do replacement alternate valves with an adaptor rather than changing sockets or cathode resistors.
Anything I've suspected of whiskers has had them when opened. Maybe tomorrow I'll cut the lid off. If it's not whiskers, and it's not like a whisker fault, then we'll never know why it's bad.
It could be something other than whiskers or junction. Whiskers are obvious tin dendrites due to too much pure tin plating. I've repaired a leg snapped off at the body, but I don't trust zapping. What about 6 years or 10 years? The tin dendrites grow slowly, but EVENTUALLY they will come back. It's a production defect and NOS Russian military and other parts are available cheaply. I'd have a different view on replacing parts in a pre-1929 set, and I'd do replacement alternate valves with an adaptor rather than changing sockets or cathode resistors.
Anything I've suspected of whiskers has had them when opened. Maybe tomorrow I'll cut the lid off. If it's not whiskers, and it's not like a whisker fault, then we'll never know why it's bad.
