[Boatanchors] Baking moisture from power transformers

[Dennis DuVall]

I was just about to recommend the same procedure. “Cooking” time variable depending on physical size and weight of the transformer, i.e., longer for large units, shorter for for smaller.  Did this successfully with an old modulation transformer (250 W) a while back.  Hooked the primary and secondary in series and ran a DC current through of about 75% of rated for a few days.

Dennis D.  W7QHO
Glendale, CA

> On Dec 22, 2014, at 12:38 PM, Dave Brown <tractorb at ihug.co.nz> wrote:
> 
> If you know the current rating of the secondary, and have a variac, short the secondary via an AC anmmeter and  power the primary through the variac-increase the primary voltage till you get the rated secondary current-this will happen at very low applied primary voltage- and let it cook from the inside for a few days. Once the core has been warm for a day or two its probably OK to stop the cooking and test at full primary voltage-after removing the short on the secondary!
> 73
> Dave
> ZL3FJ