RCA tube set with no picture and a strained flyback

[Notimetolooz]

Originally Posted by Electronic M

If you can't get the scope close enough to the set for the probes to reach you can get BNC extender cables for the probe(s)...Make sure to get the right impedance cable (most scopes/instrumentation use 50-ohm impedance cables).

That's not exactly right. Some high frequency scopes do have a setting for the input that is 50 ohm, however the more typical scope input is 1 Megohm.
Using the 50 ohm input would load down the normal points a scope would measure. Normal scope probes use special low capacitance coax.