CRTs are very rare for the R2000 series. It is, however, possible to use an
Ocilloscope as a replacement, since the original scheme used an electrostatic CRT:

Here is how I have connected an ocilloscope to the R2001.

The scope is used as a replacement for the CRT. The scope must have X, Y, and Z inputs.

    X = Vertical.
    Y = EXT Horizontal input.
    Z = Blanking input, which is often found on the back panel of the scope.

The video will be inverted (negative) unless you construct a simple video inverter.

Connections to the R2001:

All connections are to test points on the A-2 board which is next to the CRT.
The test points are in order as noted. Also note that the LV supply will not
operate with out the HV supply connected.

R2001A,B,C:
    Vert: TP4
    Horiz: TP1
    Z (video): TP8
    TP1 is toward rear of the chassis.

R2001D:
    Vert: TP1
    Horiz: TP6 
    Z (video): TP1
    TP1 is toward the front of the chassis.

Set the scope for Ext Horiz, set Vert and horoz gains for the desired scan.
Adjust scope Intensity, and 2001 Intensity for adequate display. The only
R2001 front panel control which will be inoperative is the Focus.