Appreciate the response Tom!
Resistor vs Inductor -- you're absolutely right. In my finished project, I plan to use inductor+capacitor for the reasons you describe, but have been playing with RC filters since I already have many different values of 'R' and 'C' (and currently only 1 value of 'L' -- 100uH). So if I can it working with RC filters at all, I'll proceed to LC.
Cheap capacitors:
- I am certainly using cheapo ebay capacitors. Is there a specific type/material of capacitor most suited to this purpose?
Cutoff:
- I've experimented with many different cutoff values (from 10kHz - 20Mhz) and haven't seen any dent in the noise shown in the images. Are there any drawbacks to shooting low (e.g. <=10kHz), and can I safely assume a lowpass filter with a 10kHz cutoff point will also effectively attenuate a high frequency (e.g. 25Mhz) signal? (e.g. since 10kHz <<< 25MHz, one could expect 25Mhz noise in the signal to be attenuated to ~nothingness?).
Thanks again.