Sean Breheny wrote:
> 
> In practice, I have found small electrolytic capacitors to have quite a low
> impedance to HF range RF signals (just by trying them for bypassing,not a
> scientific study ;-) SO, I would suspect that you are right, Robert.
> 
> It all depends on the self-resonant frequency of the cap. Below that freq.,
> it will act like a cap. Above it, it will act like an inductor. I don't
> know what typical values are for a small electrolytic.
> 
> ESR might actually make a MUCH bigger differnce than inductance,come to
> think of it. The ESR of a small electrolytic can easily be 20 ohms. So, if
> I'm figuring correctly, it would never appear to have a lower impedance
> than 20 ohms. I also think that ESR may increase with frequency (due to
> dielectric losses).

Actually, the Panasonic HFS series 105¡, 16V 100µF (p/n ECE-A1CFS101)
has only 1 Ohm of impedance at 100Hz and 0.1 Ohm at 1kHz.