Re: 11801 question (+GPSDO vs OXCO)

Reginald Beardsley
 

Jim,

The SD-22, 24 & 26 use 3.5 mm connectors. The SD-30 & 32 use 2.4 mm connectors. Having been infected with a severe case of "Test Equipment Acquisition" syndrome, I'm trying to cope as best I can. I'm also trying to avoid doing something stupid. I'm playing with things I never even dreamed I could have. And measuring the air gap in an SMA to 3.5 mm connection completely blows my mind!

I'm seeing a slow, persistent 5 ps variation in trace timing even after running for hours. The 11801 uses a 200 MHz OCXO. Even if it is good to 1e-8, 5 ps is 2e-11. But the scanty service data make it hard to know how the horizontal sweep clock is being generated.

Has anyone replaced the OCXO with a GPDSO. Leo Bodnar is of the opinion that the periodic drift is the sampling head.

I plan to test that tomorrow by locking my LeCroy DDA-125 to a 10 MHz reference and then comparing the OCXO output to a 200 MHz signal from the other port on Leo's GPSDO. At least if I can figure out the correct settings for Leo's dual GPSDO for 200 MHz output.

Have Fun!
Reg

Join TekScopes@groups.io to automatically receive all group messages.