[Amps] RE: 4CX250B Screen Supplies

[R.Measures]

On Jul 26, 2004, at 11:24 PM, Ian White, G3SEK wrote:

> R. Measures wrote:
>>> "The real point is that even under these favorable conditions, a
>>> zener-regulated supply (with a capacitor) *still* produces notably 
>>> more
>>> IMD than an electronically regulated constant voltage supply. This is
>>> not surprising, because a well designed electronically regulated 
>>> supply
>>> will have a much lower output impedance than a string of zeners."
>>>
>> To me it is surprising since a 2-tone, 1000Hz-spaced test should 
>> consume constant current from a C-filtered PS whether it is regulated 
>> or not..
>>
> Constant *average* current, yes - but this whole discussion is about 
> the variations above and below that average, within each modulation 
> cycle.
>
The Rate of variation of the modulation cycle in this test was 1000Hz.  
  One would think that a screen PS filter that is suitable for 
100Hz/120Hz ripple would be able to handle 1000Hz ripple.
>
> -- 
> 73 from Ian G3SEK         'In Practice' columnist for RadCom (RSGB)
> http://www.ifwtech.co.uk/g3sek
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>
Richard L. Measures, AG6K, 805.386.3734.  www.somis.org