Sounds about right. ?60 kHz is right in the range of a switching regulator of that era.
I didn’t find a signal source analyzer around the particular lab I frequent, but I’d be very surprised if there weren’t one somewhere in this building. ?Literally tons of vintage test equipment lying around here, much of it from the old Hughes Aircraft days. ?Glad you at least figured out where the spur was coming from.
Jim
toggle quoted message
Show quoted text
On Feb 24, 2025, at 12:53?PM, jmr via groups.io <jmrhzu@...> wrote:
?
Turning the backlight off makes the spurious term go away when probing :)
?
There is a soft menu button that turns off the backlight and pressing this makes the spurious vanish on the probe (that feeds to another spectrum analyser).
?
Also if I do a screen grab via Excel and GPIB (with the backlight ON) the 60kHz spurious is present on the spectrum from the baseband input. But if I grab the screen with the backlight off the baseband spectrum is clean on the grabbed screen image in Excel. A huge improvement.
?
I guess I can live with this when grabbing screen plots as (hopefully) I can add the 'backlight off' command to the excel routine.
?
So screen grabs will look much better. I'll have a look for the backlight command in the programming guide...
