[Amps] SB 221 filter capacitor replacement

[R.Measures]

On Feb 20, 2005, at 1:28 PM, Barry Norman wrote:

> Hello all,
>
> It's finally time for me to replace the original filter caps in my 
> SB221. A
> few questions:
>
> 1) Total capacitance with stock caps are 25uF (8 200uF in series), 
> should I
> increase capacitance to minimize voltage drop under load?

Hello, Norm === It won't make all that much difference if you use more 
C, but Heathkit was not known for using a surplus of filter-C.
>
> 2) Are the 105C rated caps worth the extra few bucks over the 85C?

Not if you have terminal cancer.
>
> 3) Are the different series choices only a reflection of the temp 
> ratings or
> are there other differences as well?

You can buy Panasonic's low-ESR, long-life 105ºC units for little $$ 
extra.  Digikey is a good source.
>
> Note: I've already replaced stock equalizing resistors with 100Ks. Also
> using a Peter Dahl replacement HV transformer.

Did you add a stepstart?
>
> Thanks for your suggestions,
>
> Barry Norman KF4WGR
>
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>

Richard L. Measures, AG6K, 805.386.3734.  www.somis.org