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In the 2400 series manuals, the table that defines the measurements for voltage and ripple state (for ripple measurement):

p-p Ripple at Two
Times Line Frequency

How is this supposed to be done? With a 60Hz line frequency (U.S.), is this supposed to be performed with the scope measuring the ripple triggered at 120Hz or am I misinterpreting what's being stated? Is it simply assumed that any ripple will present itself at twice the line frequency (full-wave rectification) and the scope being used to measure this will simply trigger at that frequency (assumedly using a fairly slow sweep speed to better see the waveform)?

Thanks,
Barry - N4BUQ

They are referring to ripple produced by the 120 Hz variation from the
full wave rectifier at the input. Set the measuring oscilloscope to
line triggering; that is what it is there for.

Barry, it's what you suggest, it will be ripple after double rectification. But the repetition frequency is still 60 Hz; only in case of ideal symmetry the frequency appears as 120 Hz.
Hence set the trigger mode at LINE.
If you trigger on the signal then the trigger circuitry will normally recognize 120 positive (at + slope) level crossings per second. Depending on sweep speed and hold-off time you have two alternating waveforms superimposed, or "at random" one of these two (maybe stable, maybe now and then jumping to the other waveform).

Albert


---In TekScopes@..., <n4buq@...> wrote :

In the 2400 series manuals, the table that defines the measurements for voltage and ripple state (for ripple measurement):

p-p Ripple at Two
Times Line Frequency

How is this supposed to be done? With a 60Hz line frequency (U.S.), is this supposed to be performed with the scope measuring the ripple triggered at 120Hz or am I misinterpreting what's being stated? Is it simply assumed that any ripple will present itself at twice the line frequency (full-wave rectification) and the scope being used to measure this will simply trigger at that frequency (assumedly using a fairly slow sweep speed to better see the waveform)?

Thanks,
Barry - N4BUQ