Hi,

i've a Hameg HM408 oscilloscoper analog /digital.
The problem is this:

in analog mode all it's ok.
When i use the digital mode the waweform is terrible distorted,all 2
traces has a noise(it seem a 50 HZ noise).

What could be???


Thanks for any help.

MAX

Hard to say without looking at the waveform. Some of it may be due to
general sampling or quantization errors.

How's about you put it in analog mode, then probe around the power
supply and see if the power supply voltages are okay, especially around
the digital circuitry?

HI,

thanks!

I've checked all supply voltage and semms to be ok.

Another strange thing(always in digital mode) is that when i move the
trace in the upper zone of the crt the noise linked to signal is
little.
When i move the trace in the lower zone of the crt the noise linked to
signal under test,is terribly magnified!!

mah.............