[Boatanchors] Article on changing from 2 to 3 wire power cords

Jim Bromley, K7JEB k7jeb at cox.net
Thu Aug 8 19:42:25 EDT 2019


I faced this dilemma with my 'novice' Hallicrafters S-38D. The situation
was complicated by the fact that the outer case of the receiver is metal
and the chassis kinda floats on fiber stand-offs, but not really, having
a 10K resistor between it and "B-"

I moved the power switch to the "hot" side of power (black wire),
connected "B-" directly to the "cold" side of power (white wire) and
connected the protective ground (green wire) to the metal case (but not
the chassis, that 10K resistor would have fed just enough current out of
balance to trip a ground-fault protector).

I posted the before/after schematic excerpts on the Arizona-AM website.
It is a 200K GIF file, totally safe...

  http://www.arizona-am.net/test/s38d_pwr2.gif

Jim, K7JEB

On 8/8/2019 3:11 PM, Glen Zook wrote:
> Using the ground connection for the neutral AC mains connection was never a good idea!  But, doing so did make transformerless units a little bit safer IF the ground wire was connected before connecting to the AC mains.  If the ground wire was not connected first, then a whole lot more unsafe than with a 2-wire cord.
> 
> 
> Glen, K9STH 



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