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Re: [Amps] step start

To:,, "" <>
Subject: Re: [Amps] step start
From: Paul Decker <>
Date: Mon, 2 Oct 2023 15:54:39 -0400 (EDT)
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Hi Jim,

I was actually using the Harris RF-124 power supply as a design guide, but also 
trying to use parts that I have on hand at the same time.

I'm using a Hammond 193S DC Filter Choke, inductance 1.0H @ 1000mA, 193 Series 
CHOKE 1H @ 1A DC  Seems to be about 5.6 Ohms.

As far as screen transformer, I wound my own transformer repurposing an old 
750VA transformer with an EI-152.4 core. 575V no load with 900mA.  I was just 
using 100K Ohms across the 200uF cap.  

Your question made me look closer and the RF-124 uses 30uF with a 25K 40W 
bleeder resistor.


> What's the DC resistance of the 1 H choke ?  You will want a HD bleeder on
> the screen supply at all times.  If sized correctly, the combo of the HD
> screen xfmr, choke, 200 uf cap + bleeder should provide ample screen
> regulation  for SSB use.   The dynamic regulation should be ample for both
> your proposed B+ and screen supply.
> Jim   VE7RF

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