very interesting information. Thanks.
The 11801 series has what has to be the worst FW anyone has ever written for a scope as you will shortly experience first hand. But they really are *fantastic* despite that. Just watch out for the bugs. If I execute the wrong sequence of operations I get a 1-2 order of magnitude error in the times on my 11801.
IIRC they will interpolate to 200 femtoseconds. Even at coax velocity of 2e8 m/s, that's so small a distance as to be rather "challenging". As in measuring 40 microns "challenging".
Without a detailed theory of operation, schematics, etc, it is nearly impossible to divine what Tek was doing. I'd love to know. The circuitry is so fast, that even 30 years later, Keysight can just barely beat the rise time of the 11801 calibrator.
I've got 2x SD-22, 4x SD-26 and a nice crisp 11801, with another 11801 and SD-26 for parts in CA and an SD-24 in transit. Honest, all I need now is just *one* SD-32 ;-)
Prepare to be amazed. With an SD-24 or SD-26 & the calibrator, you can test RF connectors to 20 GHz as fast as you can connect and disconnect them.
Have Fun!
Reg
