Ed, you're absolutely right. It's the same thing I thought when I started getting interested in buying one of these YTOs.
Especially the 856X series SAs are still today pretty good tools. They have a low noise floor, wide dynamics, low phase noise and digital resolution up to 1Hz. And surelythere are tens of thousands of instruments still in operation around the world. But, nevertheless, the number of YIG oscillators still seems to be too large.
But the biggest problem, I believe, is the high price required to repair them.
Even Keysight, whom I contacted, hasn't sold any in a while, but continues to repair these YTOs by shipping the complete instrument. Sum required? About 3000 euros!
They are probably shipped to the US for repair, I read in another forum that they would be built by the Microsource of Santa Rosa, and realigned on the instrument, but still it seems like an overpriced.
I understand that they are professional instruments, and I don't even want to think about how much a new instrument of similar characteristics costs today, but still they look like giants with feet of clay ...
