I recently acquired an older Wavetek 2500 signal generator (.4 - 1100 MHz) and HP 54100A 1 GHz Digitizing scope for a project and am having a difficult time in getting an accurate voltage reading using anything other than a direct-connect BNC cable, and even that seems to have it's issues. With the BNC-BNC cable (connected directly between the generator output and the scope's 50 Ohm input) and the generator set to the max output (13dB / 1V), the scope is showing a drop in voltage of roughly 50% over the full range (.4 - 1100 MHz). Is this drop in voltage abnormal or is it to be expected? Here's a list of measurements showing the drop: .4 MHz = 945mV RMS 10 MHz = 892mV 100 MHz = 757mV 500 MHz = 681mV 1100 MHz = 450mV Now, when I attempt the same test using two separate BNC-to-clip cables between the generator and scope (and connecting to grnd) I lose the consistent voltage drop over the full range of freq and instead am seeing random spikes in the voltage as I sweep the entire range. The spikes are repeatable, meaning they consistently appear at specific frequencies. Not being familiar with the equipment and having purchased it used, I was hoping that someone might be knowledgeable enough to know if the hardware is faulty or if I'm doing something wrong in the process. I would guess that the cables are the culprits but what about the 50% voltage drop with the direct BNC-BNC cable? Or is that to be expected as the freq is increased? Thanks for any help!