Someone gift me this oscilloscope and I fix some capacitators on it but I see this a bit weired.
The configuration now is two crocodrile wires with a resistor of 2K2 between both red wires, this noise come mostly from the channel 1 on channel 2 I get some noise but a bit lower.
The oscilloscope still a bit dush outside and on switchs, I don't clear all of the switches.
If I mix both channels and add the inverse of the second one I can cancel this noise.
When I set high frecuency as 20us/division and ajust it a bit, I'm not sure about the exact frecuency I saw a lot of noise on it.
Until now I fix some switch, create a new stop for one switch and replace 3 capacitors but now I don't know what I can do with this noise.
Note: the power line is 220V and 50Hz and NO GROUND... I'm replacing the power line wired with a new one but will be in 4-5 months untils I will have ground wires, I life in a old house with wires cover by sewing thread (something like that)