RLC High Pass Filter Not Working

Question

I have a signal for which I want to cutoff signal till around 3 MHz. Here is my circuit diagram.

The calculated cut-off frequency is 3.4 MHz. But when I use it, is just does not work, it seems to pass all frequencies. I am not using any load, I am just using the probe to measure the voltage across the inductor. Vin is the output from a Colpits oscillator.

Here is a frequency domain snapshot from my oscilloscope. Yellow is the input and green is the output. The reddish vertical line is where frequency is 3.17 MHz, and green vertical line is 0MHz.

I have tried lot of stuff to work it out. But nothing seems to work. In low pass mode things work fine, but in high pass mode nothing seems to work. Your guidance will be greatly appreciated.

Capacitor datasheet (Class II): http://www.mouser.com/ds/2/212/F3101_Aximax-461059.pdf

Inductor: http://www.digikey.com/product-detail/en/api-delevan-inc/1025-04J/1025-04J-ND/4183026

Answer 1

First, go do a simulation of this circuit...R1 at 10 kohms messes everything up. Try 10 ohms instead. But still it should not be passing low frequencies.

Now go look at figure 11 in your capacitor datasheet. Your 10 nF capacitor turns into an inductor at around 3 MHz.

But this circuit should still be blocking low frequencies.

Most likely, your inductor is disconnected for some reason. Either a lead is broken or you have a bad solder joint or you tried building it on a breadboard and didn't get a good contact to the breadboard. So you're seeing just the effect of the RC in series between input and output, but then when the capacitor goes inductive you start to see a low-pass effect because of whatever the load is (10 pF oscilloscope probe, maybe).