hp-23 PC board update

[mike bryce]

Hola!

Here's a update on the HP23 supply PC board project

GOOD NEWS

I got the two new prototypes for the HP23 supply built. An big improvement
in the way parts fit on the board. there's extra room now for larger bleeder
resistors for the +800 volt supply.

Added extra 125 uf @ 450 volt cap to the screen supply
Added 100k bleeder to screen supply
Added .33 ohm current limit resistor to screen supply
Added 17 watt dissipation heat sink for screen regulator regulator
Increased capacitance in bias supply


BAD NEWS

The screen regulator is still a problem. The NTE part that Dan Hall, KJ7FX,
specified is no longer being made. There is no replacement part.

Various other transistor have been tried and none have worked as well as I
liked.

Right now, the screen supply still remains the hold up



GOOD NEWS #2

Now having said that, I have modified the PC board to allow you to reuse the
swinging choke in the supply. I have one HP23 wired as such and it is now
running an hw101 as I type this.

The choke is removed and placed under the chassis. The remainder of the HP23
circuit is done by the PC board. All filters, rectifiers and bleeder
resistors are mounted on the PC board.

For those of use that only want to use the HP23 series supply with the
heathkit gear, this will work just fine.


GOOD NEWS #3

If I decide to go with the PC board that uses the old choke, there will be a
sizeable price reduction in the "KIT" price. The no longer available
transistor sells for about $10 a pop. Throw in the necessary support parts
and the total saving could hit almost $15-$20.


--
Mike Bryce WB8VGE
SunLight Energy Systems
"Electricity at the speed of light"

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