Suggestion to measure a 27Mhz signal accurately and repetably, certifiable / calibrable ...
We measure it normally with an specialy designed loads, the load as rg174 cabling 95 cm long, a precision resistor and an inductance with adjustable core and a 1.5 k 30w high precision resistor. We use inductance resistance and capacitance effects in the measurement, but basically its an voltage attenuator for a scope input. We have different scope models. Current passing thru the load is around 450 ma, witch is around 300 watts ??
I cant divuldge anything else / schematics of the loads we use
But i can say its unreliable, if the inductance move physically, the read value change, if the rg174 wire is pinched, or changed with an almost identical lenght the read values change, the rg174 wire heat....
Lots of things affect the read value, and what bothers me the most, the department fiddle with the scope compensation screw to fit the value between scopes, each scope has its own deficated load. And for reference we have a very stable 27Mhz reference signal, but it use the same load technology
We use an BK Precision 2kv x100 scope probe red color, i cant find the specs or part number at the moment.
I need some suggestions to measure this signal amplitude correctly, a power meter ?? I need to measure it maximum half a minute.
And can be calibrated ...
thks