General > General Technical Chat

Sketchy Oscilloscope Knob

(1/4) > >>

tayexdrums:
I have an old Hitachi V-423 40MHz scope that was given to me for free. Now I'm definitely not complaining here because of the fact that it was given to me for free. However, there is a small problem with the scope. Sometimes, when I use the calibration output on the scope there will be a distortion in it. I have to wiggle the volts per division knob in order for the trace to get back to the shape of a calibrated square wave. I have taken a video of it which I think will provide more information.

Please let me know if anyone has any advice or information on how to fix it=]

PeterG:
The cause is simple, the cure is hard. It is most likely caused by bad/dirty contacts on the rotary switch. The hard part can be getting to the switch to clean the contacts.

regards

mikeselectricstuff:
If the contact issues are caused by long term non-use, operating the switch a few dozen times may help clean it - always worth a try before diving in.

tayexdrums:
That's what I thought the problem was. I didn't think it was something that was very technical. I took the case off yesterday and looked to see if I could easily get to the switches, but they were definitely down in there. I would have to take some time and take somethings apart=\

I will first try turning the switches a lot to see if that helps though.

Simon:
you could try WD-40, it does not conduct and is well known for cleaning switches and the like

Navigation

[0] Message Index

[#] Next page