[Boatanchors] Heathkit PS-1 Power Supply

[Ken Kaplan]

It's interesting to note that Heath used a resistor in all of their 
similar power supply designs. I'm sure cost was a significant factor. If 
you use a 7 Hy choke, that will effectively be about a 5,400 ohm 
resistor at 120 Hz (according to my old boatanchor Shure Reactance Slide 
Rule). Just make sure its insulation resistance is adequate as well as 
its current capacity. I'd go for a lower DC resistance choke if you have 
a choice. Let the reactance do the work. I'd also replace those 2 
electrolytic caps. AES has a 33 (C-ET33-450) and a 10 (C-ET10-450) that 
are cheap. Plenty of other sources.

Ken

n2lxm at juno.com wrote:
> Good Evening All,
>
>         I was able to get a few hours on the bench this week and finished
> up on the PS-1 supply. I would like some input on a modification I am
> thinking about. The supply uses a resistor in the range of 300 to 500 ohm
> in between the dual section electrolytic cap. I would like to see a bit
> more filtering and load/line regulation from the supply. Now I know this
> is not a top of the line, super regulated unit. So I am think about
> replacing the resistor with a 7 Hy choke. The choke has about the same DC
> resistance as the resistor that is in the supply now. what difference
> should I see and is it worth the effort to do. Any and all input is
> welcomed.
>
>
>                                 Jeff N2LXM
>                   AMATEUR RADIO OPERATOR
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