Mains Input Filter

[Ranger14]

I am repairing a Tek 2215 Non A and one of the upgrade was to get rid of the noisy  transformer.. Well I can't get the parts for the upgrade and saw in the post they installed a mains input filter.. Right now it has the standard computer style plug and manage to find a common mode mains input filter.. Would it make any difference to install the common mode mains input filter vs a standard plug to pcb

Thanks

[Jwillis]

A mains line filter keeps power spike and line transient noise from entering your circuit .In your case a oscilloscope.A good one will have surge suppression as well.So for an instrument like your oscilloscope I would put one in.It's a little extra peace of mind.
   

[FrankE]

Go for it. They're a few bucks and you should be able to find one of a suitable form factor to easily retrofit into place.
I 'm not familiar with the model but as you stated 'old' it'll no doubt be pre EN 55011 CISPR 11 era whatever the US eq

If you have equipment with switched mode power supplies they can put guff on the mains. Input filters work both ways and attenuate the guff and transients going onto the line.

Perhaps worth  fitting appropriate line filters on other older electrical appliances,