Andy Green wrote: > I looked at this last night, but my setup is too crap to get a sensible > result. All I have around is some old scope probes terminating in BNC, > so I cut one off and used that cable from the tracking generator (it's
Aiii ... if that's from a capacitative probe, that's going to be evil. Here is a very nice article about the various probe types and their characteristics: http://www.sigcon.com/Pubs/straight/probes.htm A bit off-topic: DIY probes are a very good thing to have. In my case, it's not about ringing or bandwidth limits, but I need them to win the daily battle against EMI from the microwave antenna clusters, cellular and other stuff, surrounding my lab at eye level. Here's an example of a basic resistive probe ending in a 2-pin socket for a 0.1" header: http://people.openmoko.org/werner/rigol/r-probe.jpg And here you can see one attached to a header soldered to a GTA02: http://people.openmoko.org/werner/sdio-test-setup.jpg For the scope end, if the scope doesn't have a built-in 50R termination, you can either build it into the BNC connector or use a 50R feed-thru terminator, e.g., Digi-Key 501-1036-ND http://www.tequipment.net/CalTestCT2944.html http://www.dilette.com/main/dilettesales/DL-22_feed-thru_terminator.html For the cable, another option besides DIY would be to buy a pre-made BNC-RG174-BNC cable and to cut it in half. That's actually cheaper than buying the individual components (well, if S&H don't drive the price up): http://www.l-com.com/item.aspx?id=206 In any case, I found that a spool of RG-174 cable and a few BNC connectors are very good things to have around. - Werner _______________________________________________ hardware mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/hardware
