Building a simple LC 15mhz Lowpass Filter?

[rwgast_lowlevellogicdesin]

So I would like to build a 30 and 15mhz lp filter. Everytime I run the info through a filter calculator and then an air inductor core inductor winder I end up with some rediculous 4 million turn inductor no matter what value I use for C. Am I missing something here? I know this can be done with an active filter or even some chip pretty easy but it would be super handy to just use a cap I have and wind an inductor....

[Cmcada]

What is the filter to be used for?

Will an RC filter not suffice?

1.1Ohm
0.01uF

Will get you close to 15Mhz.

I don't know if there is any benefits to using inductors other than power dissipation.

[PA0PBZ]

So I would like to build a 30 and 15mhz lp filter. Everytime I run the info through a filter calculator and then an air inductor core inductor winder I end up with some rediculous 4 million turn inductor no matter what value I use for C.

Yeah, a 15 millihertz filter will need quite a large coil, better try 15 Megahertz 

[rwgast_lowlevellogicdesin]

opps.... I use elctrodroid a nice android app, if you havent seen it pretty handy. The pop up KB was covering Mhz and I was using mHz. Weird I have a huge screen and I still had to flip the stupid thing to make the KB go away so I could select Mhz! But it turns out I need 5 wraps for a 25mhz filter lol.

Im using it for an analog SDR frequency pre-selector , using an R-C in this instance would drop the DB's considerably correct?

[LukeW]

http://www-users.cs.york.ac.uk/~fisher/lcfilter/

I had a quick play around with a 5th-order Cheby lowpass at 15 MHz and I got (in order from input to output) 50-ohm series terminator, 160pF shunt, 692nH series, 335pF shunt, 692nH series, 160pF shunt, and a 50-ohm shunt termination on the output, assuming 50-ohm transmission lines on either end. Change those to closest standard LC values.