[R-390] Is your R390A Power Cord Connected Correctly ?

chuck.rippel at cox.net chuck.rippel at cox.net
Mon Dec 3 23:01:43 EST 2012


Been running into radios where people (quite correctly) add a 3 wire 
cord in place of the 2 wire.  In some casese, the connections for the 
neutral and hot side of the line at the back of the radio. under the 
removable protective cover have been reversed.  The result has been, the 
hot side of the input was not fused and did not switch off.  Rather it 
was the neutral which was fused and switchesd  1 short to chassis 
ground, no fuse would blow and......  Also, the transformer always had 
115V on the primary as measured to chassis ground.  Not a good situation 
at all.

Is yours so configured?  To check, unplug the radio and remove the 2 
nuts securing the rear panel A/C line input cover.   !! Make a 2nd check 
that the R390A A/C line has been unplugged !!!   Pull the fuse and with 
an ohm meter, check continuity from the line side of the fuse to the 
rear panel connection where the black wire on the line cord is 
connected.  It should read 0 ohms.  If there is no black wire, ohm from 
the line side of the fuse to that prong on the line cord which would 
plug into the narrow side of your A/C outlet.

0 ohms from the line side of the fuse to the black wire or to the prong 
which plugs into the narrow side of the outlet is correct.  If not, 
reverse the A/C connection on the back of the radio attaching the black, 
hot wire to the terminal which is connected to the line side of the 
fuse.

Do not make this check and subsequent countermeasure unless you fully 
understand the process and end result.


---
No  trees were killed to deliver this message.  However, a large number 
of electrons were terribly inconvenienced.

Chuck Rippel


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