[NJARC] Radio Debugging PS

[Scott Roberts]

Hi Al-
The old ones seemed to be working ok, and they were in good
physical condition: also, I figured since they were dry caps(as
opposed to wet caps)they woud probaby be ok to use... I just
changed them out for the 22/450s John recommended...

Right now I'm checking out one of my mica caps- the end covering
is missing, and I am thinking it may be compromised. It is one of
the mica ones which looks like a white ceramic resistor.(C-31,
.000010mfd) It originally had a ceramic "cap" at each end- and
one is chipped away entirely.

I also replaced the other electrolytic John recommended...

Thanks Al-
I am having fun :) I enjoy learning how this all works...

Scott
 
--- Al Klase <al at ar88.net> wrote:

> Visit our web site - See http://www.njarc.org
> _______________________________________________
> Hi Scott,
> 
> Why didn't you replace the main filter caps when you're
> agonizing over 
> all the minor details?  They're 70 years old, and are the ones
> that are 
> going to kill your power transformer when they short out. 
> Leave them in 
> place.  Cut them dead, and install some new caps below decks.
> 
> While it's a good idea to make sure each tube has reasonable
> plate and 
> screen voltages, it's a fool's errand to carefully measure all
> the 
> voltages, and attempt to access the condition of the set from
> the 
> resulting matrix.  What works?  What doesn't?  Which stage is
> questionable?
> 
> 1.  Signal trace to the BAD STAGE.
> 2.  Make voltage measurements in that stage to identify the BAD
> 
> CIRCUIT.  (Plate, screen, grid, etc.)
> 3.  Turn off the power, and make resistance measurements to
> find the BAD 
> COMPONENT.
> 
> (Testing the tubes is a good idea as well.)
> 
> Clear the first problem and move on to the next one,
> 
> Have fun,
> Al
> 
> Scott Roberts wrote:
> > Visit our web site - See http://www.njarc.org
> > _______________________________________________
> > PS- I replaced all the paper caps, and a coupe electrolytics,
> but
> > NOT the two large electrolytic caps C-44 & C-45, both 16mfd @
> > 400V. I replaced electrolytic cap C-40, 10mfd @ 25v, with a
> 10mfd
> > 450. Is this too big? or just overkill?
> >
> > Scott
> >
> > --- Scott Roberts <ng19delta at yahoo.com> wrote:
> >
> >   
> >> Visit our web site - See http://www.njarc.org
> >> _______________________________________________
> >> Hi Everyone!
> >> I am finishing up my recap on the Hallicrafters SX-16.
> Today, I
> >> checked the voltages on the tubes, using an  Extech True RMS
> >> DMM,
> >> Model 22-816. I am working with about 113VAC house current.
> 10%
> >> tolerances, per manual. Settings IAW Hallicrafters manual
> >>     
> >
> >
> >
> >      
>
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> >
> >   
> 
> -- 
> Al Klase - N3FRQ 
> Flemington, NJ 
> http://www.skywaves.ar88.net/
> 
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> 



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