@JMR
If you read Jinxie's first post to this thread you will find she does have a "good" probe:
"The scope I am using for this test is a 350Mhz Tek analog one and it can 'see' waveforms perfectly well at half gig when connected with a high bandwidth probe (my 3.5Ghz one) so I know the scope's not at fault.
Any suggestions?"
I assume that at 3.5GHz it is probably an active probe.
Loading is immaterial for comparision and as the "good" probe is rated to 10x the max test frequency it's response can be ignored.
@Jinxie
Just about any BNC T will do thor this as it is a comparison.
