[RFI] Big Farad versus Hybrid Caps?

[Michael Keane K1MK]

On 6/19/2009 4:06 PM, kd4e wrote:

> I need to manage the load-spikes from a SSB modulated HF signal
> through a solid state RF amp.
> 
> Rather than two $190. 90lb batteries I can use one large battery and
> one Hybrid cap and in my intermittent load application be in good
> shape.
> 
> Yes?

No. The cap is of no benefit for the dynamic load application

Because of its relatively high equivalent series resistance, an 
electrochemical capacitor cannot discharge quickly enough to help supply 
some of the current needed on voice peaks.

Used in a car, an electrochemical cap is effective at keeping the 
headlamps from dimming because the filaments in the lamps respond 
slowly. But in that application, such a device doesn't prevent the car 
stereo (or radio) from seeing the same voltage fluctuations under 
modulation. That's why these super capacitors for car audio systems are 
all hype; it's the wrong application for this technology.

73,
Mike K1MK