[Amps] Filter capacitors and L-input filters

[John Lyles]

Here is an old report on the problems inherent in LC and multiple LC section power supply filters for transmitters, for those who want to read about it but don't design around it:

http://www.amwindow.org/tech/htm/tutor.htm
Then download the two part article Power Supply Design and Dynamic Regulation, from GE Ham News.

73
John
K5PRO

> ##  when playing with conventional choke input supplies, not the resonant types that
> henry radio used,  you are in for an eye opener.  When you 1st turn it on,  you get this
> huge  yo-yo oscillation on the P-P  v waveform, that finally settles down.   what psud wont
> simulate is a varying load, like ssb-cw.  Once the supply is up and running, and no more
> soft start involved, is when the trbl starts up.     Every time you hit the key,  you are slamming this
> big load on it...and you end up toggling between full and no load.   Every time you hit the key, 
> that oscillation starts up, and P-P V is sky high, till it settles down.   On cw, that?s next to impossible. 
> 
> ##  By playing around for hrs on end with psud, you can minimize the effect some what. 
> Psud will handle anything from doublers to FWB  to anything else.  Then you can use stuff like
> L-C-L filters or  C-R-C filters, or just C.    Then its easy to see what the P-P  ripple voltage will
> be for any given load, no rocket science here...and the software is dead on for the most part. 
> You can also factor in the Z of the plate xfmr, and wiring back to main panel. 
> later...  Jim  VE7RF