On Fri, Feb 21, 2025 at 03:02 AM, G8HUL wrote:
....but as has been stated here many times before damage level is far different form that which will give a realistic reading.
The 8568 is different from the TinySA in that its input attenuator is real resistors and can withstand 1W without damage, but there is still the necessity to ensure that sufficient attenuation is selected so that the SA is not overloaded and gives a sensible answer.
The wat to do that is to monitor both the fundamental and the harmonic and increase the attenuation level, and if the harmonic level (or fundamental) varies by more than the change in attenuation then you are not at a level that will give a true answer.
73
Jeff G8HUL
Thank you Jeff for this interlude of sanity.??
I was trained to start in a completely safe input level range, wide sweep, look for all the signals, calculate and note the safe maximum level (as Min attenuation) ,
THEN use the excellent HP attenuation range to sweep the on screen signal level up and down within that range until the fundamental and all harmonics of interest all moved in sync? which I think is what you are describing.? I can't remember this typically being the case at Max/damage input level or even near but who knows.??
Anyway? each to their own ...
Bruce Akhurst