[Amps] L-4PS Transformer Buzz

[Michael Tope]

On 2/15/2010 10:05 AM, Carl wrote:
> Could be a bad cap, one installed wrong (it will blow eventually but 
> it will get real warm first), missing, miswired or bad equalizing 
> resistor.
> The transformer is trying to tell you to stop!
>
> Carl
> KM1H
>
Carl/Dick, et al.

I triple checked the polarity of the caps before I put the cover on the 
PS and they are installed properly. Also, I didn't see any swelling or 
smell anything from the PWB after I fired up the supply, but I'll pull 
the lid off and take a closer look.

Regarding Dick K5AND's suggestion, the transformer is held is 8 places. 
4 bolts on the bottom, and 4 on the top. I had the bolts on the top out 
to replace the 50Kohm x 50W power resistors used to derive the cutoff 
bias. That may have changed the mechanical pre-load on the transformer. 
Maybe I'll let the PS warm up and then loosen and re-tighten those bolts 
to see if that helps.

Thanks,

Mike W4EF...........