HP8591E drift at zero span
Hi everybody how are you?
As the title, is the problem that I found in my recently acquired SA
Done all self calibration procedure.
- TG calibration
- Amplitude Calibration
- Frequency Calibration
Setting the TG to 10.000 Mhz at zero span
Counter show at list 7.61 Khz out of range.
I found that the frequency are out of set and with constantly drift and randomly frequency jumps.
Taking a superficial look over the SA, I found over the option101(Fast Time-Domain Sweeps and Analog+Display)
5062-7079 board, some interesting signal to show whit the oscilloscope.
As seen on the screen, the scope show some kind of Arbitrary signal with an average of 19.5 Mhz
and 735mv rms
I suspect that the problem coming from the option 101, but I not sure of that.
I uploaded a couple of videos where the problem is clearly seen.
If anyone has seen this problem before, please comment.
Thanks in advance,
Albert.
Drift of the tracking generator signals on these analyzers is typical. The reason is that there is a free running oscillator in the tracking generator assembly that is used to mix with the 1st LO to create the output signal. This is why the resolution bandwidth of these instruments has to be set to a fairly wide value when using the tracking generator. When you execute the tracking peak function it adjusts the frequency of this free running oscillator to align it such that the output aligns with the input frequency. But it will drift around as you are seeing...
Mike