One time fixing a BC transmitter where the rectifier bases were arcing
over after a lightning transient came in on the power line, I chipped
off the aluminum from the 872 ceramic and the ceramic socket, then
applied Krylon (red was on the shelf) as that insulating barrier. I'm
sure Glyptal or corona dope would have been better but I didn't have
those in my tool box and the station had the red Krylon on the shelf. I
was 25 miles from the nearest electronic distributor and couldn't find
out if anything else was bad until I could get the plate voltage to come
up. Their insurance company was glad to see me succeed in putting them
back on the air.
73, Jerry, K0CQ
On 6/9/2010 5:42 PM, pfizenmayer wrote:
> When you open it to dust it out - look carefully at the PC board between the
> two HV wires from the transformer - there have been some random arcs
> /tracking there - on mine they even added some Glyptal like black varnish on
> those connections.
>
> 73 hank K7HP
>
> ----- Original Message -----
> From: "Stuart Rohre"<rohre@arlut.utexas.edu>
> To:<tentec@contesting.com>
> Sent: Wednesday, June 09, 2010 12:39 PM
> Subject: Re: [TenTec] Centurion 422B
>
>
>> I once had a low powered rig that developed such an arc over in standby,
>> and it turned out to be a burned out place in the potting of the high
>> voltage transformer winding. It would arc to the metal can in which the
>> transformer was potted. A cure suggested was to heat up the transformer
>> (removed from rig) on a hot plate to remelt the tar and then to test for
>> the fix.
>>
>> But, usually, this symptom is dust accumulation within a linear upon
>> various insulated parts.
>>
>> -Stuart Rohre
>> K5KVH
>>
>>
>> _______________________________________________
>> TenTec mailing list
>> TenTec@contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|