ORIGINAL MESSAGE: (may be snipped)
On Sat, 12 Oct 2013 09:44:39 -0700, W7RY wrote:
>That is incorrect Bill.
>
>The schematic of the SB-1000 (an looking at the one currently on my
>bench) clearly shows the open interlock controls the one and only AC
>power relay to the rest of the amplifier. No filament or high voltage is
>present with the interlock switch open.
>
>Unless you count the voltage not yet bled down from the filter capacitors.
>73
>Jim W7RY
REPLY:
Maybe I wasn't clear. The schematic for the SB-1000 is correct in the sense
of how it SHOULD be wired, but if you follow the step by step instructions
in the construction manual, you will get the safety defect mentioned above.
Remember, this was more than 20 years ago and subsequent production may have
the defect corrected. Like I said, I never heard back from Heath so I don't
know.
In any event, owners should make the simple test as originally described.
With the cover removed, power up the amp and see if there is any HV present.
If the meter shows zero, you are OK. If it shows any amount of HV, you have
some rewiring to do.
As I recall, the amount of HV was not the full amount but only a few hundred
volts or so. Just enough to kill you.
73, Bill W6WRT
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