[GreenKeys] Re: Dovetrons

[Doug Alderdice]

At 12:01 PM 2/14/05 -0500, Roy Morgan wrote:
>At 05:24 PM 2/12/2005, Doug Alderdice wrote:
>>I measure 60 VAC between the frame of the Dovetron to either the shield 
>>or audio out line of my computer's sound card.  Tried reversing the line 
>>cord to the Dovetron and same result.
>
>This sounds like the classic line fllter bypass problem.
>
>The Dovetron Tempest units have a robust line RFI filter installed, and 
>MUST be plugged into a well grounded outlet.

I found that out the hard way.

>Short fix: run a wire from the Dovetron chassis to the computer chassis.
>
>Better fix: put a 1:1 600  ohm transformer between them in the audio line.

Built up a little perf board last night with exactly that on it for "the 
next time," but will also be putting a proper 3-wire power cord on the 
thing, too.  Just didn't have any 3-wire cord stock on hand this weekend so 
threw a 2-line one on it for testing and trying out the audio 
stuff.  Poof.  Meanwhile I am printing just fine with my old HAL ST5000 off 
the remaining working audio channel on my computer.

Doug.