[David Light]

I'm having little luck finding exact replacement values for
the HF-87 power supply capacitors. In most applications I would just
go with a larger value and move on. Would this be a problem in this
circuit?

[Peter Wieck]

On Nov 8, 8:42*pm, (David Light) wrote:
* * * * I'm having little luck finding exact replacement values for
the HF-87 power supply capacitors. *In most applications I would just
go with a larger value and move on. *Would this be a problem in this
circuit? *

Electrolytic caps, unless marked as precision caps, may be as much as
-20%/+100% and still be within tolerance.

You have a pretty wide range on the up-side.

Peter Wieck
Melrose Park, PA

[PhattyMo[_2_]]

Peter Wieck wrote:
On Nov 8, 8:42 pm, (David Light) wrote:
I'm having little luck finding exact replacement values for
the HF-87 power supply capacitors. In most applications I would just
go with a larger value and move on. Would this be a problem in this
circuit?

Electrolytic caps, unless marked as precision caps, may be as much as
-20%/+100% and still be within tolerance.

You have a pretty wide range on the up-side.

Peter Wieck
Melrose Park, PA


I would try to find the closest value cap I could,for the first
position,right after the (assumed) tube rectifier. Too large of a cap
here can result in arc-over,and rectifier tube death.
The rest of the caps you can take a bit more liberty with the values.

[Peter Wieck]

On Nov 9, 2:26*am, PhattyMo wrote:
Peter Wieck wrote:
On Nov 8, 8:42 pm, (David Light) wrote:
* * * * I'm having little luck finding exact replacement values for
the HF-87 power supply capacitors. *In most applications I would just
go with a larger value and move on. *Would this be a problem in this
circuit? *

Electrolytic caps, unless marked as precision caps, may be as much as
-20%/+100% and still be within tolerance.

You have a pretty wide range on the up-side.

Peter Wieck
Melrose Park, PA

I would try to find the closest value cap I could,for the first
position,right after the (assumed) tube rectifier. Too large of a cap
here can result in arc-over,and rectifier tube death.
The rest of the caps you can take a bit more liberty with the values.

Sure. If 30uF is OEM, and you add 200uF, you *may* have problems. But
if 30uF is OEM and you go back with anything from about 27 - 47uF, you
will be fine.

Peter Wieck
Melrose Park, PA

[David Light]

On Sat, 08 Nov 2008 23:26:21 -0800, PhattyMo wrote:

I would try to find the closest value cap I could,for the first
position,right after the (assumed) tube rectifier. Too large of a cap
here can result in arc-over,and rectifier tube death.
The rest of the caps you can take a bit more liberty with the values.

The power supply uses a couple of solid state diodes for rectifiers
in a voltage doubler. The caps are 300 uF. I can find 335 uF caps
that will fit well. As another poster said about specs, these are
well within tolerances of the original caps.

[PhattyMo[_2_]]

David Light wrote:
On Sat, 08 Nov 2008 23:26:21 -0800, PhattyMo wrote:

I would try to find the closest value cap I could,for the first
position,right after the (assumed) tube rectifier. Too large of a cap
here can result in arc-over,and rectifier tube death.
The rest of the caps you can take a bit more liberty with the values.

The power supply uses a couple of solid state diodes for rectifiers
in a voltage doubler. The caps are 300 uF. I can find 335 uF caps
that will fit well. As another poster said about specs, these are
well within tolerances of the original caps.


Ahh,Gotcha. Yes,those caps will work fine,as long as the voltage rating
is up to snuff.
If the SS diodes are originals,you might consider replacing them with
something newer.There are alot of good diodes available these days.