[R-390] Opening The Power Transformer

[Bob Camp]

Hi

I suspect it depends very much on what caused the transformer to fail. If a lightning hit / line over voltage caused an arc then you will get a carbon track somewhere. If a short on the secondary plus shoddy line fuse caused an over temperature situation, you will get a very different failure.

Bob

On Mar 17, 2013, at 11:23 AM, g4gjl at btopenworld.com wrote:

> Does this failure mode apply to R390A and R390/ 391 transformers also?
> 
> Pete
> G4GJL
> 
> 
> 
> 
> ________________________________
> From: Steve Hobensack <stevehobensack at hotmail.com>
> To: r390 reflector <r-390 at mailman.qth.net> 
> Sent: Sunday, 17 March 2013, 14:45
> Subject: [R-390] Opening The Power Transformer
> 
> I have posted this message before, sorry. The power transformer can be easily opened by hammer tapping a putty knife through the solder seam. The failure of the winding will most likely occur where the high tension winding enters the small porcelain bushings as it exits the metal casing.  The tar potting material will carbon track to case ground here. The tar can be removed in this area with a heat gun and screwdriver. 
> Steve N8YE                           
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