17-07-2015, 08:59 AM
Back to the Real World.
I got the PSU back on the Bench and, after a bit of Head scratching, jumpered up the Load to give suitable values for the -170V and +70V. The Results were, to say the least, unimpressive.
The -170 would still only go to -165 which is odd because I'm sure it did when I first tried it.
Again, I can't think that 5Volts would make a difference to the other Units. Nevertheless, the -170 is the source of all Wisdom for the PSU so it seems a bad idea not to start with it correct.
Here with the Manual's view of the possible problems:-
And the Schematic:-
Certainly everything looks clean, tidy and unstressed.I measured all the Resistors in-situ and they all seemed reasonable - I'm reluctant to disconnect the ones on the Tag Strips unless I have to because of the Silver-loaded Solder, although I have some. However I did disconnect R9 1nd R11 at the Pot end and they measure spot on - they're precision ones. I also tried adding some Resistance to them which made not one iota of difference.
So, there'll be a short intermission while I do some Valve Testing. I haven't got any spares of course
Alan
I got the PSU back on the Bench and, after a bit of Head scratching, jumpered up the Load to give suitable values for the -170V and +70V. The Results were, to say the least, unimpressive.
The -170 would still only go to -165 which is odd because I'm sure it did when I first tried it.
Again, I can't think that 5Volts would make a difference to the other Units. Nevertheless, the -170 is the source of all Wisdom for the PSU so it seems a bad idea not to start with it correct.
Here with the Manual's view of the possible problems:-
And the Schematic:-
Certainly everything looks clean, tidy and unstressed.I measured all the Resistors in-situ and they all seemed reasonable - I'm reluctant to disconnect the ones on the Tag Strips unless I have to because of the Silver-loaded Solder, although I have some. However I did disconnect R9 1nd R11 at the Pot end and they measure spot on - they're precision ones. I also tried adding some Resistance to them which made not one iota of difference.
So, there'll be a short intermission while I do some Valve Testing. I haven't got any spares of course
Alan
