[BC] Knight Kit

[Harold Hallikainen]

 > Yes, looking back it's amazing how dangerous they built electronic
 > equipment
 > in those days.  Connecting one side of the AC line to the chassis was a
 > very
 > common practice for cheap electronics in the 1950s and before.  Even the
 > simple precaution of using a polarized plug would have improved safety
 > greatly but manufactures didn't even do that.  I eventually leaned to use
 > a
 > neon-bulb to check line polarity every time I plugged something in.  But
 > it's a wonder we baby-boomer electronic experimenters ever made to
 > adulthood!   (-;
 >
 >  - Nat


As I recall, one side of the line went through the power switch to the
chassis. If the plug was in one way, the chassis was at zero volts (or
thereabouts, it was connected to neutral) when the unit was on, but at
120VAC when the unit was off. Reverse the plug and the chassis was at zero
volts when the unit was off, but at 120VAC when the unit was on. It also
two RCA phono plug inputs with the shells grounded, so your record player
ALSO got to have a hot chassis.

Harold