[Heathkit] Regulator for PS-9000 Power Supply

[Mark K3MSB]

OK,  thanks to all the replies (especially Ed).   I didn't realize the 5V
reference voltage was internal.

My test circuit now shows the new regulator working,  and old one failing.

Thanks for the help guys!

73 Mark K3MSB

On Wed, Aug 4, 2010 at 8:31 PM, Tom Frobase <tfrobase at gmail.com> wrote:

> From memory, the regulator has an internal 5 volt reference.  Google
> the data sheet.  There is a formula for calculating the resistor
> values ... Tom, N3LLL
>
> On 8/4/10, Mark K3MSB <mark.k3msb at gmail.com> wrote:
> > OK.   I'm frustrated.
> >
> > I got the new regulator in (Thanks John!) and I can not get the test
> circuit
> > to work that's in the spec sheet.
> >
> > It's the regulator with 2 resistors and 2 caps;  this is not rocket
> > science,  but I can't get it to work.
> >
> > Regardless of what values I select for R1 and R2 ,  Vout = Vin (always)
> with
> > Vc = 5.0 Volts.
> >
> > I'm using a 12V regulated supply for Vin.
> >
> > I've tried R2 = R1 = 5K.   I expect Vout to be 10V.
> >              R1 = 5K and R2 = 10K;  I expect Vout to be 7.5V
> >
> > I'm missing something........   nuts.....
> >
> > 73 Mark K3MSB
> >
> >
> >
> > On Fri, Jul 16, 2010 at 2:12 PM, Mark K3MSB <mark.k3msb at gmail.com>
> wrote:
> >
> >> Greetings !
> >>
> >> I'm trying to fix a PS-9000 power supply for the SS-9000 Transceiver,
>  and
> >> I think the regulator is shot.
> >>
> >> The regulator (Heath Part Number 442-685) is the out of production
> >> UA78GKC.   I cross referenced this to ECG1926, but it seems to be out of
> >> production as well,  although it's still available from a few "out or
> >> production" sources;  I have emails out to these places for prices,  but
> >> nothing's come back yet.   I'm wondering if they don't want to deal with
> a
> >> customer that want's only one unit.
> >>
> >> On the off chance....   anybody have a spare in their parts box they'd
> >> care
> >> to sell?
> >>
> >> Thanks
> >>
> >> Mark K3MSB
> >>
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