[R-1051] Fuses

[Steve Hobensack]

The same thing happens to the hi-tension terminals on the r-390a power 
transformer.
....Steve...N8YE

>From: "Geoff Fors" <wb6nvh at mbay.net>
>Reply-To: R-1051 Discussion Group <r-1051 at mailman.qth.net>
>To: <r-1051 at mailman.qth.net>
>Subject: [R-1051] Fuses
>Date: Mon, 7 Feb 2005 15:53:25 -0800
>
>A couple of years back I posted a comment regarding blown fuses on 1051's.
>I have found that sometimes the high voltage terminals of the power
>transformer arc to ground through the rubber seal between the case and
>porcelain insulator.  Apparently the rubber becomes conductive with age due
>to carbon content.  Anyway, the transformer can be repaired by carefully
>crushing the porcelain insulator sleeve, digging out all traces of the
>rubber seal, and creating a new seal and insulator out of good quality 
>epoxy
>such as J-B Weld (pay no attention to the "steel" logo on JB Weld; it 
>hipots
>well past 1 KV!)
>
>This problem sometimes shows up as intermittent fuse blowing, but usually
>once the arc starts it carbonizes the whole seal and creates a constant
>low-resistance short to the case.
>
>Geoff Fors
>
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