Gene Pink
Well-known member
Alexandru marian said:Now let's kill the 150,250,350 etc
Actually, it is 50, 150, 250, 350..., a 50 Hz fundamental, with odd-order-harmonics extending well up into the Khz. A typical line frequency buzz.
Since there is 50 Hz in there, the only place 50 Hz should exist in that circuit is the transformer and the diodes. Everything after that should be just the 100Hz ripple, unless something is mismatched. Grossly different diode forward voltages, transformer secondary winding a turn or two off on one side, a large difference in turnoff, (or as I think of it, "stuck-on") times between the diodes, any of these could let some 50Hz past where the diodes connect together to form your B+, and all of them quite unlikely.
But consider this possibility: One of the diodes could be leaking in reverse, somewhere right up near the 775 PRV that these diodes see. That could spew out some sharp spikes 50 times a second, and would look like your noise floor spectro graph.
Just a shot in the dark from left field, but I would try a new set of diodes, of at least 1KV PRV, perhaps 1N4007's, if they will handle the current you need. What is in there now?
Gene
