[Amps] AL-811H popping fuses

[Tom Osborne]

Well - got it fixed.  It was the filter caps.  Also ran into another 
problem (that I caused) when working on it.

I was going to take the sub chassis with the tube sockets out to check 
the bottom.  After loosening one of the screws, found it was the one 
that held the tube socket in, not the one that held the chassis in. 
After loosening it, I decided not to take the chassis out.

Problem was - now I've got a loose screw holding the socket in as the 
nut fell off.  No problem - right?

Yes, there was a problem.  When I fired the amp up, I was getting a bad 
motorboating sound in the radio.  Rechecked all the caps and they were 
tight.  I took the tubes out and put them back in one at a time to see 
if it made the noise.  Put 3 of them in and all was OK, but when I got 
to the last one, the noise started again.  It was the one with the loose 
screw on the socket.

I had to remove the sub-chassis to get to the bottom of it and put the 
nut back on and now all is OK.  Seems that was holding the ground for 
the grid.  Doesn't work very good when it's loose :-)  73
Tom W7WHY