[Amps] L4B Caution

[Paul Baldock]

I suggest you remove the bleeder resistors. They serve no purpose 
other than to speed up the bleed down when you turn the amp off. They 
create a lot of unnecessary heat in the supply.

- Paul   KW7Y



At 10:32 AM 7/25/2013, Ed K0KL wrote:
>I had a bad experience when working on an L4B for a pal. The bleeder 
>resistor mounting
>scheme proved to be a little poor (unusual for Drake). When 
>reinstalled, one of the resistors
>shorted to the mounting screw.
>This bleeder is held in place by a screw that goes through the 
>center of the resistor. Mica slices
>insulate the ends (chassis and screw head). Only thing is the 
>resistor arced through the ceramic
>base material. So I used glass tape to insulated the screw on the 
>reinstalled components. This
>provided better spacing to the center of the screw.
>Note- I replaced the resistors, having the same thing reoccur. Only 
>with the use of the tape did
>the thing calm down. Ordinary electrical tape won't work as it will 
>melt caused by the heat of
>the resistors.
>
>Anyway, that was some time ago, the amp is going strong. Except for 
>a rather weak plate
>transformer, this puppy will no doubt last several lifetimes.
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