That was uncharitable, it could be that you don't understand the beast at all so I'll give some pointers:
1) It MUST be in a shielded enclosure, not just a metal box but one that is RF SHIELDED. That means the ends that Luftek provided are nice for mounting the connectors but they are NOT shielded. And if your box is still anodized where they come together then it is NOT shielded. Shield the device FIRST then move on to the next step which is:
2) Power supply. It MUST be a linear if you don't want spikes.
Computer power supplies and wall warts don't cut it, they CREATE spikes because they are switching supplies.
Get a linear power supply THEN you can do the next step which is:
3) Isolate the computing system noise over the USB cable.
Ferrite beads will help here, though a proper large ferrite doughnut and multiple turns of the USB cable through it will attenuate most of the noise, one at each end will pretty much cover that entry point.
OR you can do it right by double shielding inside the enclosure between the USB external socket and the onboard USB socket via capacitive bulkhead passthrough posts in the shielding divider. Same for the power connections.
THAT is the way it is done professionally.
While you are at it use a USB cable that does NOT have power leads to keep the ultra noisy computer power supply off the line.
After that if you have spikes with the antenna's disconnected you might have something to complain about otherwise they are ENVIRONMENTAL and you are going to have to track them down in your house, your neighbours house, the power poles up and down the street, etc etc ad nauseum.
In fact if you don't see spikes with the antenna disconnected then ANY spikes you see are external to start with.
A mistake a few here have already made.
Did you understand all of that? Because if you haven't done ALL of that then you haven't even started to quiet down your SDR.