[Central-Electronics] Slicer PS-1 help

[K6JEK]

It's alive!  It's alive!  The leaky mica capacitor in the PS-1 was  
the last bad part between nothing much working and  most things  
working pretty well.    I replaced the 4300 pF mica with a 3300 ||  
1000 hand picked to come very close to 4300.

I suppose I should test the few micas that I haven't tested yet.  Of  
the ones I have tested, two have been bad.   All the paper caps were  
bad but the micas seemed to be in places that mattered.

Moral:   Pretty as they are, as faithful as they have been, trust no  
more the mica cap

Jon

On Aug 30, 2007, at 11:01 PM, K6JEK wrote:

> George,
>
> I agree.   In fact, I have now discovered that C8 is very leaky,  
> more of a resistor than a capacitor.   The schematic shows all the  
> caps in the PS-1 as variable caps but they are, in fact, mica caps  
> paralleled by trimmers.  C8 is a goner.
>
> Some of my Collins collector friends have told me that the old rule  
> off thumb that paper caps are probably bad and micas never are is  
> no longer true.   This is the second bad mica cap I've found in  
> this unit.
>
> I'll let you know if replacing this cap made the difference.
>
> Jon, K6JEK
>
> On Aug 30, 2007, at 7:40 PM, George Maier wrote:
>
>> Very nice tip, Jim.
>> Jon: before you get to tweaking, you should take the time to check  
>> the
>> resistor values, and make sure that the fixed caps are not open or  
>> shorted.
>> Not too much chance of them being leaky, but you never know.
>> 73 & good luck,
>> George - W1LSB
>>
>>

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