• Probe schematics and spikes

    Hi to all!
    I would display output signal from differential output amplifier: Out+, Out- and signal ground/shield.
    Signal outputs through a 3-way PCB screw terminal block, due I am using oscilloscope probe I only get ground and Out+ using a two short wires, just to collect signal using oscilloscope probe.
    Using oscilloscope probe I read clear signal, I used different oscilloscope probes (I don't remember models, that ones are default probes for MSO46 and TDS210).
    Issue starts when I use direct coaxial cable with BNC connector instead oscilloscope probe: I see spikes I can't understand where they come from.
    I changed cable type (RG58 and others) but with no effect.
    It looks like a low-pass filter on the oscilloscope probe.
    Are there available probe schematics?
    Do you suggest specific cable for homemade probe?
    I'll post image as soon I can.
    Any suggestions/ideas?
    Thanks.