You can make a simple variable frequency oscillator with just a LM358, just takes a very few components, connect your pickup across a capacitor, something between .1uF and 1 nF Apply the output of the VFO to the pickupu/cap circuit though a 10K resistor, using a pot connected as a frequency control on the LM358 sawtooth VFO circuit below, then just connect your scope across the pickup/cap and turn the pot and you will see the resonant frequency as a sharp rise in the mV range on your scope.
You connect a 1K to 10k pot to +Vcc (let us say at the positive of a 9V battery powering this circuit), other side of pot to ground, the center of the pot goes to the +VC* point shown on the schematic below.
The transistor in the circuit can be any general purpose npn transistor such as 2N3904 etc.
The resonant freq is 1/((2*pi* (SqrRoot(*L*C))) or the 1/Period that you see the best peak to peak action at on your scope.
Hope you can do the math.
http://www.allaboutcircuits.com/vol_2/chpt_6/2.htmlAs far as the Hantek, goes, here is a really bad review of the software that is used with it:http://www.google.dk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0CCgQtwIwAQ&url=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DbEuPtWE8FOI&ei=X6T_U5XDAaShyAOS74HQCw&usg=AFQjCNG0bdw79SXhE1KxNaTC1HhfT45fpQ&bvm=bv.74115972,d.bGQ