A while ago I bought a couple of 4352A VCO Analyzers, mainly out of curiosity and because they were cheap.
I had since then time to play around with those and wanted to share my findings with the group.
All in all I consider the 4352A a instrument worth having in a well equipped lab especially if your work involves PLL Synthesizers or VCOs.
Basically it allows to characterize VCO and PLL oscillators in one box.
The unit can measure phasenoise, output power, frequency and spectrum up to 3GHz, it contains low noise voltage sources for tuning and supply voltage.
You can measure output power and frequency vs tuning voltage, measure spurs and phasenoise and drift, the unit has a build in ibasic controller that allows to write automation programms and control pll oscillators via serial or paralell interface.
The spectrum analyzer function however is a bit disapointing, it only allows for a span of 10MHz max which is sufficient to find close in spurs but not sufficient for harmonics. The unit can measure phase noise at offsets from 100Hz to 10MHz which is sufficient for most applications, the noise floor of the unit is around -158dBc.
Sure there are better solutions out there but for $300-600 you can consider this box a bargain.
Lothar