HELP - SB-301 LMO

[Chris Trask]

On Fri, 4 Sep 1998, Kastigar wrote:

> Help!  SB-301, mostly dead.  If I substitute a signal generator for the
> LMO, the receiver comes to life.  The B+ is 145v, but drops to +115
> after the tubes warm up (?). The filament voltage is OK, as is the bias
> (either +60 or -59vdc).  The screen (g3) voltage is +135vdc, with the
> tube removed.
>
> Any ideas???
>
        Hmmm...  If the screen grid voltage drops like that, then the tube
is okay.  I would look at the output on a 'scope and see what's there, if
anything.  I would suspect an open capacitor or a solder joint that has
gone south, which will require open Hartley surgery.

        Sorry, I couldn't help myself.  :{)


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