[Hallicrafters] SX28 power transformer

[zuu6k at juno.com]

Back in 1955 we had a severe flood in Yuba City, CA. I got water 3 inches
from the ceiling in my house. I worked for Sears as a TV repairman. We
removed the power transformers from the then tube-type submerged TV's and
after removing the covers submerged them in hot paraffin >212 degrees F.
We left them there until the bubbling stopped (all the moisture
evaporated). After dripping dry and cooling off, we reassembled them. If
the customer had not turned it on to try it, we saved a lot of them.

73, Ed K6UUZ


On Fri, 29 Jul 2005 14:28:06 -0500 k0ewu at juno.com writes:
> SOAP BOX #2 ON!                
>         Regarding this "Bring it up slow on the"variac".
> This is of no good as the rectifier cannot conduct till the cathode 
> is
> hot.
> then the almost full voltage is applied.
> If you really want to do this, put a solid stat rectifier in place 
> of the
> tube, 
> monitor the dc plate voltage and the tx input current.if all goes 
> well
> the input current will increase as the input voltage increases and 
> should
> drop down as the caps reform.The dc out will follow the input, but   
> if
> the dc suddenly drops quite a bit
> and no longer increases as the input does--there is a low 
> resistance
> short some where.  
> 
> BUT do not do this if the rig has been stored in a damp or high 
> humidity
> location
> for some months.     next
> 
>  AN easy way to warm the trans former is to apply  dc current of 
> about
> 700 ma to the ac input, short the rectifier socket plate to plate 
> to
> protect from surges as the dc is applied or removed.
> The transformer should warm up from the current in the primary in a 
> short
> time , let it cook this way for 6 to 8 hours, remove the short on 
> the hv
> winding (at the tube socket)
> after the dc is removed
> then use the forming excersize as above.
> I have used this method for years to dry out motors, transformers 
> and
> other ac devices after total immersion in flood waters and other 
> fresh
> water dunking.
> 
> cAN OTHERS ADD TO THIS?  comments?
> 
> JACK----------K0EWU at juno.com
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